JP6908474B2 - Wafer cleaning device - Google Patents

Description

The present invention relates to a wafer cleaning device that cleans the outer peripheral edge of a wafer.

When manufacturing a wafer having a flat surface in the manufacturing process of a semiconductor wafer, for example, a columnar ingot is thinly cut with a wire saw or the like to obtain a disk-shaped wafer. Since undulations are often present on both sides of the wafer, a rotating grinding wheel is brought into contact with the cut surface of the wafer, and the undulations on the cut surface are removed by grinding.

In performing the grinding process, for example, a protective member is formed of a liquid resin on one surface of a disk-shaped wafer. Then, by grinding the other surface of the wafer, the waviness of the other surface of the wafer can be removed. After that, the protective member is peeled from the wafer by a peeling device, and one surface of the wafer protected by the protective member is ground to produce a wafer in which waviness is removed from both sides and the thickness is uniform.

However, when the protective member is peeled off, a resin (protective member) peeling residue may occur on the outer peripheral edge of the wafer, and if this resin peeling residue is present, the wafer will have an even thickness when one surface is ground. do not become. Therefore, the resin left after being peeled off is removed by washing with a roll-shaped sponge. A cleaning device equipped with a roll-shaped sponge that cleans the outer peripheral edge of the wafer supplies cleaning water to the sponge and rotates the wafer and sponge while pressing the sponge against the outer peripheral edge of the wafer to perform cleaning. (See, for example, Patent Document 1).

JP-A-2015-170741

When the wafer is washed as described above, the sponge is pressed against the outer peripheral edge of the rotating wafer, so that the side surface of the sponge is scraped and consumed. When the sponge is exhausted, the sponge cannot be sufficiently brought into contact with the outer peripheral edge of the wafer to be newly cleaned, and cleaning cannot be performed. Further, for example, when the cleaning device is stopped for a long period of time, the sponge is completely dried and contracted, so that it takes time to impregnate the sponge with cleaning water to inflate it and restore its elasticity. If the sponge starts cleaning a new wafer in a state where the elasticity is not fully restored even if the sponge absorbs the cleaning water, the sponge cannot be sufficiently brought into contact with the outer peripheral edge of the wafer, so that the cleaning is not possible. Will be enough.

Therefore, in a cleaning device that cleans the outer peripheral edge of the wafer, the sponge can be cleaned in order to prevent insufficient cleaning due to the small area of contact of the sponge with the outer peripheral edge of the wafer. There is a problem to be able to recognize whether or not it is in.

The present invention for solving the above problems is a waiha cleaning device for cleaning the outer peripheral edge of a waiha, which has a holding means having a holding surface for holding the waha and a roll shape on the outer peripheral edge of the waha held by the holding means. A cleaning means for contacting the outer surface of the sponge to clean the outer peripheral edge of the wafer, a moving means for relatively approaching or separating the holding means and the cleaning means in the direction of the holding surface of the holding means, and the sponge. The holding means includes a washing water nozzle for supplying washing water and a judgment means for determining whether or not the sponge is in a washable state, and the holding means causes the outer peripheral portion of the wafer to protrude and the central portion to be sucked by the holding surface. A holding table for holding and a rotating means for rotating the holding table around the center of the holding surface are provided, and a light projecting unit that emits measurement light and a light receiving light that receives the measurement light by sandwiching the sponge. The measuring light has a width, a predetermined width of the width is shielded by the sponge, and the light receiving portion receives the measurement light that is not shielded by the sponge. If the light receiving amount of the light receiving part is larger than the preset light receiving amount, it is judged that the sponge cannot be washed, and if the light receiving amount of the light receiving part is less than the preset light receiving amount, it is judged that the sponge can be washed, and the sponge is held. The determination means makes a judgment in a state where the means and the cleaning means are separated from the outer peripheral edge of the wafer by a predetermined distance from which the sponge contacts, and when the determination means determines that the sponge can be cleaned, the holding means and the cleaning means are used. It is a waiha cleaning device that cleans the outer rim of the waha by positioning the means at a predetermined position and bringing the outer rim of the waha held by the holding means into contact with the outer surface of the sponge.

It is preferable that the light emitting portion and the light receiving portion are arranged in the holding means.

In the wafer cleaning device according to the present invention, the holding means and the cleaning means are brought close to each other by the moving means so that the light receiving amount of the light receiving portion becomes a preset predetermined light receiving amount, and the holding means and the cleaning means are brought close to each other. A second determination means for determining whether or not the sponge is in a washable state is provided in place of the determination means, and the second determination means is such that the distance between the holding means and the cleaning means is large. If it is closer than a predetermined distance, it may be determined that cleaning is not possible, and if it is more than the predetermined distance, it may be determined that cleaning is possible.

The waiha cleaning device according to the present invention includes a first storage unit, and the first storage unit stores the amount of light received immediately before the sponge is determined to be washable by the determination means, and the first storage unit is used. It is further provided with a third determination means for determining that cleaning is not possible when the difference between the amount of light received stored by the storage unit and the amount of light received when the determination means determines that cleaning is possible this time is larger than a preset difference. Then, it is preferable.

The waiha cleaning device according to the present invention includes a second storage unit, and the second storage unit includes the holding means and the cleaning means immediately before the second determination means determines that the sponge can be cleaned. The distance between the two is stored, and the distance stored by the second storage unit and the distance between the holding means and the cleaning means when the second determination means determines that the cleaning means can be cleaned this time. It is preferable to further provide a fourth determination means for determining that cleaning is not possible when the difference is larger than a preset difference.

The waiha cleaning device according to the present invention has a holding means having a holding surface for holding the waha and a cleaning means for cleaning the outer peripheral edge of the waiha by bringing the outer peripheral surface of the roll-shaped sponge into contact with the outer peripheral edge of the waha held by the holding means. A moving means for relatively approaching or separating the holding means and the cleaning means in the holding surface direction of the holding means, a cleaning water nozzle for supplying cleaning water to the sponge, and determining whether the sponge is in a washable state. The holding means includes a holding table that protrudes from the outer peripheral portion of the wafer and sucks and holds the central portion on the holding surface, and a rotating means that rotates the holding table around the center of the holding surface. A sponge is provided with a light projecting unit that emits measurement light and a light receiving unit that receives measurement light across a sponge. The measurement light has a width, and a predetermined width of the width is shielded by the sponge. The light receiving part receives the measurement light that is not blocked by the light receiving part, and the judgment means determines that the sponge cannot be washed if the light receiving amount of the light receiving part is larger than the preset light receiving amount, and the light receiving amount of the light receiving part is equal to or less than the preset light receiving amount. If this is the case, it is determined that the sponge can be washed, and the determination is made in a state where the holding means and the cleaning means are separated from a predetermined distance at which the sponge contacts the outer peripheral edge of the wafer. Therefore, when the sponge is worn out and has a small diameter, it cannot be sufficiently contacted with the outer peripheral edge of the wafer and the cleaning becomes insufficient, or the sponge to which the cleaning water is supplied swells sufficiently. When the wafer is in a state where it is neither dry nor elastic (dry and hard), it cannot be sufficiently contacted with the outer peripheral edge of the wafer and the cleaning becomes insufficient. It is possible to make a judgment before the start of cleaning. Then, when the determination means determines that cleaning is possible, the holding means and the cleaning means are positioned at predetermined positions, and the outer peripheral edge of the wafer held by the holding means is brought into contact with the outer surface of the sponge to clean the outer peripheral edge of the wafer. , It becomes possible to appropriately clean the outer peripheral edge of the wafer for each wafer.

Since the light emitting part and the light receiving part are arranged in the holding means, the holding means is positioned at a predetermined position, so that the light emitting part and the light receiving part are positioned at appropriate positions and the sponge can be washed. It is possible to make it possible for the judgment means to judge whether or not the light is present.

In the wafer cleaning device according to the present invention, the holding means and the cleaning means are brought close to each other by the moving means so that the light receiving amount of the light receiving portion becomes a preset predetermined light receiving amount, and the sponge is formed by the distance between the holding means and the cleaning means. A second determination means for determining whether or not the cleaning means is possible is provided in place of the determination means, and the second determination means cannot be cleaned if the distance between the holding means and the cleaning means is closer than a predetermined distance. It is judged that cleaning is possible if the distance is more than a predetermined distance. Therefore, when the sponge is worn out and becomes smaller, it cannot be sufficiently contacted with the outer peripheral edge of the wafer and the cleaning becomes insufficient, or the sponge to which the cleaning water is supplied is sufficiently inflated. When the wafer cannot be sufficiently contacted with the wafer due to its lack of elasticity (dry and hard) and the cleaning becomes insufficient, the second judgment means is used for cleaning. It becomes possible to judge before the start.

The waiha cleaning device according to the present invention includes a first storage unit, and the first storage unit stores the amount of light received immediately before the sponge determines that the sponge can be washed, and the first storage unit stores the light reception amount. The determination means is further provided with a third determination means for determining that cleaning is not possible when the difference between the amount of light received immediately before the last time and the amount of light received when the determination means determines that cleaning is possible is larger than a preset difference. Even if the sponge is judged to be washable, it is possible that the sponge is not actually fully inflated and is in an inappropriate state for cleaning the outer periphery of the wafer. In some cases, a third determination means can further determine whether the sponge is in a washable state.

The waiha cleaning device according to the present invention includes a second storage unit, and the second storage unit is a distance between the holding means and the cleaning means immediately before the second determination means determines that the sponge can be cleaned. The difference between the distance immediately before the second storage unit memorized and the distance between the holding means and the cleaning means when the second determining means determines that cleaning is possible is a preset difference. By further providing a fourth determination means for determining that the sponge cannot be washed when the size is larger, even if the second determination means determines that the sponge can be washed, the sponge is actually sufficient. If the sponge is not inflated and may be in an unsuitable condition for cleaning the outer periphery of the wafer, the fourth means of determination should be used to further determine whether the sponge is in a washable condition. Can be done.

It is sectional drawing when the wafer cleaning apparatus is seen from the side. It is explanatory drawing when the wafer cleaning apparatus is seen from above. It is a flowchart explaining the flow of each process performed in the case of removing the waviness of one surface and the other surface of a circular plate-shaped wafer. It is a schematic explanatory drawing explaining the state which the protective member is formed with the liquid resin on one surface of a wafer. It is a side view which shows the state which holds the protective member and grinds the other surface of a wafer. It is explanatory drawing which explains the state which the holding means was positioned at a predetermined position from the side in order to judge whether or not the sponge is in a state which can wash the outer peripheral edge of a wafer. It is explanatory drawing which explains the state which the holding means was positioned at a predetermined position from above in order to determine whether or not the sponge is in a state which can wash the outer peripheral edge of a wafer. It is a top view which shows the state which the measurement light is shining on the sponge which is not consumed and which swells sufficiently by absorbing wash water and has elasticity. It is a graph which shows the example of the signal (light receiving amount value) output from the light receiving part to the determination means. It is a top view which shows the state which the measurement light is shining on the sponge which is exhausted or is not swelling enough even if it absorbs wash water. It is a graph which shows the example of the signal (light receiving amount value) output from the light receiving part to the determination means. It is explanatory drawing which explains the state which the holding means was positioned at a predetermined position from the side in order to judge whether or not the two sponges are in a state which can wash the outer peripheral edge of a wafer. In the explanatory view from the side, the state where the measurement light is projected onto the two sponges that are not consumed and have sufficient elasticity due to the absorption of the washing water. be. When one sponge is worn or not sufficiently inflated and the other sponge is not worn and is sufficiently inflated, the state in which the measurement light is projected onto the two sponges is seen from the side surface. It is explanatory drawing when seen. When the other sponge is worn out or not sufficiently inflated, and one sponge is not worn out and is sufficiently inflated, the state in which the measurement light is projected onto the two sponges is seen from the side surface. It is explanatory drawing when seen. It is sectional drawing when the outer peripheral edge of a wafer is brought into contact with the outer surface of a sponge, and the sponge and the wafer are rotated to wash the outer peripheral edge of a wafer from the side. FIG. 5 is a cross-sectional view of a state in which the cleaning means and the holding means are tilted by the tilting means when viewed from the side during cleaning of the outer peripheral edge of the wafer. It is a perspective view which shows an example of the spinner cleaning apparatus which cleans one surface and the other surface of a wafer. FIG. 5 is a cross-sectional view of a wafer cleaning device provided with a second determination means instead of the determination means when viewed from the side. It is explanatory drawing when the wafer cleaning apparatus provided with the 2nd determination means instead of the determination means is seen from above. When the holding means is brought closer to the washing means by the moving means in order to judge whether the sponge is in a state where the outer peripheral edge of the wafer can be washed from the side. It is explanatory drawing. Description of the case where the holding means is brought closer to the cleaning means by the moving means in order to determine whether or not the sponge is in a state where the outer peripheral edge of the wafer can be washed from above. It is a figure. It is sectional drawing when the outer peripheral edge of a wafer is brought into contact with the outer surface of a sponge, and the sponge and the wafer are rotated to wash the outer peripheral edge of a wafer from the side.

(Embodiment 1 of Wafer Cleaning Device)
The wafer cleaning device 1 shown in FIG. 1 is a device for cleaning the outer peripheral edge Wd of the circular plate-shaped wafer W held by the holding means 3 with the cleaning means 2.
The holding means 3 includes a holding table 30 that protrudes from the outer peripheral portion of the wafer W and sucks and holds the central portion on the holding surface 300a, and a rotating means 31 that rotates the holding table 30 around the center of the holding surface 300a. There is.

The holding table 30 is formed in a circular shape having an outer shape smaller than that of the wafer W, and includes a suction portion 300 made of a porous member or the like and communicating with a suction source (not shown), and a frame body 301 for supporting the suction portion 300. .. The holding table 30 can suck and hold the wafer W on the holding surface 300a which is the exposed surface of the suction portion 300 and is flush with the upper surface of the frame body 301.

The rotating means 31 arranged on the lower side of the holding table 30 includes a rotating shaft 310 whose upper end is fixed to the bottom surface side of the holding table 30, and a motor 311 for rotating the rotating shaft 310. The axial direction of the rotating shaft 310 is the Z-axis direction, and the center of the holding surface 300a of the holding table 30 is located on the extension line of the axis of the rotating shaft 310.

On the lower side of the holding means 3, a moving means 4 for relatively approaching or separating the holding means 3 and the cleaning means 2 in the direction of the holding surface 300a of the holding means 3 (in the present embodiment, the Y-axis direction) is arranged. It is installed. The moving means 4 includes a ball screw 40 having an axial center in the X-axis direction, a guide rail 41 arranged in parallel with the ball screw 40, and a motor 42 for rotating the ball screw 40. A movable block 34 having a nut that constitutes the holding means 3 and is screwed into the ball screw 40 is slidably arranged on the guide rail 41. When the motor 42 rotates the ball screw 40, the movable block 34 is guided by the guide rail 41 and moves in the Y-axis direction, and the holding table 30 arranged on the movable block 34 via the rotating means 31 is a movable block. It moves in the Y-axis direction with the movement of 34.

The wafer cleaning device 1 is composed of a storage element such as a CPU and a memory, and includes a control means 19 for controlling the entire device. The control means 19 is connected to the moving means 4, the rotating means 31, and the like by wiring (not shown), and under the control of the controlling means 19, the moving operation of the holding table 30 by the moving means 4 and the rotation of the holding table 30 in the Y-axis direction. The rotation operation of the holding table 30 by the means 31 is controlled.

For example, the moving means 4 includes a Y-axis direction position detecting means 45 for measuring the position of the holding table 30 in the Y-axis direction. The Y-axis direction position detecting means 45 reads the scale 450 extending in the Y-axis direction along the guide rail 41, and the scale 450 fixed to the movable block 34 and moving together with the movable block 34 along the scale 450 to read the scale of the scale 450. It is provided with a unit 451. The reading unit 451 is, for example, an optical type that reads the reflected light of the scale formed on the scale 450, detects the scale of the scale 450, and detects the position of the holding table 30 in the Y-axis direction.

The moving means 4 may not include the Y-axis direction position detecting means 45, and the position of the holding table 30 in the Y-axis direction may be detected as follows. For example, the motor 42 of the moving means 4 is a pulse motor that operates by a drive pulse supplied from a pulse oscillator (not shown). Then, the control means 19 detects the position of the holding table 30 in the Y-axis direction by counting the number of drive pulses supplied to the moving means 4.
Alternatively, for example, the motor 42 of the moving means 4 may be a servomotor, and the rotary encoder may be connected to the servomotor. The rotary encoder outputs an encoder signal (rotational speed of the servomotor) to the control means 19 after the operation signal is supplied from the control means 19 to the servomotor. The control means 19 calculates the amount of movement of the holding table 30 in the Y-axis direction from the encoder signal sent from the rotary encoder, and detects the position in the Y-axis direction.

For example, the side wall 212 of the cleaning box 21 of the cleaning means 2 is fixed to one end of the guide rail 41 of the moving means 4, and the holding means 3 and the cleaning means 2 are attached to the other end of the guide rail 41 by the −X axis. A tilting means 10 capable of tilting clockwise or counterclockwise when viewed from the direction side (the front side of the paper in FIG. 1) is connected.

The tilting means 10 comprises a rotating shaft 100 having an axial center in the X-axis direction, a motor 101 for rotationally driving the rotating shaft 100, and a connecting member 102 to which the guide rail 41 is fixed and rotating with the rotation of the rotating shaft 100. I have. The wafer cleaning device 1 may be configured not to include the tilting means 10. Further, the cleaning means 2 and the moving means 4 may be tilted in advance, and the tilting means 10 may tilt only the holding means 3.

The cleaning means 2 includes a roll-shaped sponge 20 and a cleaning box 21 for accommodating the sponge 20 inside, and is rolled on the outer peripheral edge Wd of the wafer W held by the holding means 3 inside the cleaning box 21. The outer surface of the sponge 20 is brought into contact with each other for cleaning.

The sponge 20 is formed by forming a sponge having a predetermined thickness into a roll shape (cylindrical shape), and in the example shown in FIG. 1, the sponge 20 is arranged in the cleaning box 21 so that the longitudinal direction is parallel to the Z-axis direction. It is installed. The sponge 20 is, for example, a sponge made by foam-molding polyurethane, and becomes swelling and elastic by absorbing washing water from a state in which it is dry, shrinks, and hardened. The outer surface of the sponge 20 is a cleaning surface for cleaning the outer peripheral edge Wd of the wafer W.

The sponge 20 is rotatably hollowly supported inside the cleaning box 21 by the sponge rotating means 22, and its position in the cleaning box 21 is fixed. The sponge rotating means 22 includes a rotating shaft 220 that is inserted through the sponge 20 and supports the sponge 20, and the rotating shaft 220 is attached to the top plate 210 of the cleaning box 21 via a bearing (not shown). A motor 221 that rotationally drives the rotary shaft 220 is connected to the upper end side of the rotary shaft 220.

The cleaning box 21 has, for example, a columnar outer shape having a cavity inside, an exhaust port 210a is formed on the top plate 210 thereof, and a drainage port 211b is formed on the bottom plate 211 thereof. A drain hose (not shown) is connected to the drain port 211b, and the drain hose communicates with a wastewater tank or the like. A wafer entrance 212a into which the wafer W enters is formed on the side wall 212 of the cleaning box 21. The wafer entrance 212a is formed by cutting out the side wall 212 in the shape of an arc slit.

An air curtain forming means 24 is arranged in the vicinity of the wafer advance entrance 212a in the cleaning box 21. Two air curtain forming means 24 are arranged so as to sandwich the wafer W entering from the wafer advance entrance 212a from the vertical direction, and as shown in FIG. 2, the cleaning box 21 is arranged when viewed from the Z-axis direction. It extends in an arc shape along the wafer entrance 212a. The air curtain forming means 24 ejects compressed air from the vertical direction to the wafer W that has entered the wafer advance inlet 212a, and forms an air curtain that covers the wafer advance inlet 212a by the flow of the compressed air. This air curtain prevents the cleaning water adhering to one surface Wa or the other surface Wb of the wafer W from flowing out from the wafer entrance 212a to the outside of the cleaning box 21.

As shown in FIG. 1, for example, two cleaning water nozzles 29 for supplying cleaning water to the sponge 20 are arranged in the cleaning box 21. The cleaning water nozzle 29 communicates with a cleaning water supply source (not shown) that stores cleaning water (for example, pure water), and injects cleaning water onto the sponge 20 from an oblique direction in the vertical direction. The cleaning water supplied from the cleaning water nozzle 29 to the sponge 20 flows down to the bottom plate 211 of the cleaning box 21 and then drains from the drain port 211b to the outside of the cleaning box 21.

As shown in FIGS. 1 and 2, the wafer cleaning device 1 includes a determining means 5A for determining whether or not the sponge 20 can be cleaned. Further, the wafer cleaning device 1 includes a light projecting unit 50 having a built-in light source and projecting measurement light across a sponge 20, and a light receiving unit 51 (not shown in FIG. 1) that receives measurement light. The light projecting unit 50 and the light receiving unit 51 are arranged, for example, so as to face the tips of the support bars 35A and 35B fixed to the movable block 34 of the holding means 3 in the X-axis direction. A transmissive photoelectric sensor is formed by the light emitting unit 50 and the light receiving unit 51, and the light receiving unit 51 sends a detection signal (value of the light receiving amount) to the determination means 5A.

The support bar 35A and the support bar 35B shown in FIGS. 1 and 2 are integrated with the arm portion 350 which is fixed to the side surface of the movable block 34 by a fixing screw or the like (not shown) and extends in the + Y direction, and the tip side of the arm portion 350. A light emitting portion 50 is provided at the upper end of the support portion 351 of the support bar 35A, and a light receiving portion is provided at the upper end of the support portion 351 of the support bar 35B. 51 is arranged. Therefore, as the movable block 34 moves in the Y-axis direction, the light emitting unit 50 and the light receiving unit 51 move in the Y-axis direction. The height positions of the light projecting unit 50 and the light receiving unit 51 in the Z-axis direction are substantially the same as the height positions of the wafer advance entrance 212a formed on the side wall 212 of the cleaning box 21.
The light projecting unit 50 and the light receiving unit 51 are not arranged in the holding means 3, and can be moved in the Y-axis direction independently of the movement of the movable block 34 of the holding means 3 by a moving means (not shown). You may.

Hereinafter, each step in the case of removing the waviness of one surface Wa and the other surface Wb of the circular plate-shaped wafer W will be described. FIG. 3 is a flowchart illustrating the flow of each step to be performed when removing the waviness of one surface Wa and the other surface Wb of the circular plate-shaped wafer W. The wafer cleaning device 1 shown in FIG. 1 according to the present invention is used when carrying out an outer peripheral edge cleaning step for cleaning the outer peripheral edge of the wafer shown in FIG.

(1) Protective member forming process of supplying resin to one surface of a wafer to form a protective member The wafer W shown in FIG. 4 has a circular plate-like outer shape, and one surface Wa and the other surface are provided. A swell (not shown) is formed in Wb.
First, in order to grind the other surface Wb of the wafer W, as shown in FIG. 4, a protective member is formed on one surface Wa of the wafer W with the liquid resin S1. Specifically, for example, the film S2 is placed on the flat holding surface 90a of the holding table 90 shown in FIG. 4, and a predetermined amount of the liquid resin S1 is supplied onto the film S2 from the resin supply device 91. The resin S1 has, for example, a property of being cured by ultraviolet rays. Then, after the holding means 92 sucks and holds the other surface Wb of the wafer W, the holding table 90 is positioned below the holding means 92. Then, the liquid resin S1 is spread by the wafer W held by the holding means 92 so that the entire surface Wa of one surface of the wafer W is covered with the liquid resin S1. The liquid resin S1 also wraps around the outer peripheral edge Wd of the wafer W, and the outer peripheral edge Wd is also covered with the liquid resin S1.
Next, the liquid resin S1 is irradiated with ultraviolet rays from the ultraviolet irradiation mechanism 93 arranged inside the holding table 90 to cure the liquid resin S1, and the protruding portion S2a in which the film S2 protrudes from the outer peripheral edge Wd of the wafer W is formed. The film S2 is cut into a circle having a diameter larger than the diameter of the wafer W so as to be formed, and the protective member S shown in FIG. 5 composed of the resin S1 and the film S2 is formed.

(2) First Grinding Step of Grinding the Other Surface of the Wafer with a Grinding Wheel Next, as shown in FIG. 5, the wafer W on which the protective member S is formed is conveyed to the grinding device 94, and the protective member S is transferred to the grinding device 94. The wafer W is suction-held on the holding surface of the chuck table 940 of the grinding device 94 so that the other surface Wb that is not formed faces upward. Then, the grinding wheel 941 rotating from above the wafer W descends, and the grinding wheel 941a is brought into contact with the other surface Wb of the wafer W to perform grinding. After the other surface Wb of the wafer W is ground by a predetermined amount to remove the waviness, the grinding wheel 941 is separated from the wafer W.

(3) Protective member peeling step of peeling the protective member from one surface of the wafer after grinding The wafer W is then conveyed from the grinding device 94 to a protective member peeling device (not shown). In the protective member peeling device, for example, the protruding portion S2a of the protective member S of the wafer W shown in FIG. 5 is gripped by the gripping clamp, and the gripping clamp holding the protruding portion S2a and the wafer W are relatively outside the wafer W. The protective member S is peeled off from one surface Wa of the wafer W by moving it radially from the peripheral edge Wd toward the center. However, the resin residue of the resin S1 constituting the protective member S may be generated on the outer peripheral edge Wd of the wafer W.

(4) Wafer W for cleaning the outer peripheral edge of the wafer The wafer W from which the protective member S has been peeled is transferred from the protective member peeling device (not shown) to the wafer cleaning device 1 according to the present invention by the transport means 18 shown in FIG. Be transported. The transporting means 18 includes, for example, a suction pad 180 having a disk-shaped outer shape and sucking and holding a wafer W on its lower surface (suction surface), and an arm 181 that supports the suction pad 180 and can move in the horizontal direction and the vertical direction. It has.
The transport means 18 that attracts and holds the wafer W moves to the upper part of the holding table 30 shown in FIG. The suction pad 180 that sucks and holds the wafer W is positioned above the holding table 30 so that the center of the suction surface substantially coincides with the center of the holding surface 300a of the holding table 30, and then descends onto the holding surface 300a. Wafer W is placed in. Then, the holding table 30 causes the outer peripheral portion of the wafer W to protrude from the holding surface 300a and sucks and holds the central portion of the wafer W on the holding surface 300a, and the suction pad 180 is separated from the wafer W.

For example, the sponge 20 of the wafer cleaning device 1 is prepared so that the outer peripheral edge Wd of the wafer W can be cleaned. That is, the washing water is supplied from the washing water nozzle 29 to the sponge 20, and the sponge 20 is prepared to swell and have elasticity by absorbing the washing water. After a predetermined amount of washing water is supplied to the sponge 20 from the washing water nozzle 29, the supply of washing water is stopped.

As shown in FIG. 6, the moving means 4 moves the holding table 30 holding the wafer W in the + Y direction, and under the position detection by the Y-axis direction position detecting means 45 and the control by the control means 19, the Y-axis direction. The holding table 30 is stopped at the position Y1 in. The position Y1 is a predetermined position for the determining means 5A to determine whether or not the sponge 20 is in a state where the outer peripheral edge Wd of the wafer W can be washed, and when the holding table 30 is positioned at the position Y1. The light projecting unit 50 emits the measurement light. As shown in FIGS. 6 and 7, the measurement light emitted from the light projecting unit 50 in the + X direction passes through the wafer advance entrance 212a of the cleaning box 21 of the cleaning means 2, and a part thereof passes through the sponge 20. The light is received by the light receiving unit 51 while being shielded from light.
The position Y2 in the Y-axis direction shown in FIGS. 6 and 7 is a position where the outer surface of the sponge 20 comes into contact with the outer peripheral edge Wd of the wafer W when the holding table 30 is positioned at the position Y2. Even if the holding table 30 holding the wafer W is positioned at the position Y1, the outer peripheral edge Wd of the wafer W and the sponge 20 are not in contact with each other.

The determination by the determination means 5A as to whether or not the sponge 20 is in a state where the outer peripheral edge Wd of the wafer W can be washed is performed, for example, as shown below. FIG. 8 shows a case where the sponge 20 is not consumed and the sponge 20 has sufficiently swelled and elastic due to the absorption of the washing water. The diameter of the sponge 20 in this case is defined as the diameter R1. For example, the light projecting unit 50 passes the light emitted from the built-in light source through a rectangular slit long in the Y-axis direction, converts the transmitted light of this slit into parallel light (measurement light) through a collimator lens, and converts the measurement light into parallel light (measurement light). While maintaining a predetermined width (for example, width D1) in the Y-axis direction, the light is projected in a straight line in the X-axis direction toward the light receiving unit 51. In FIG. 8, only the sponge 20, the determination means 5A, the light emitting unit 50, and the light receiving unit 51 are shown, and the other components of the wafer cleaning device 1 are omitted. In the above embodiment, the measurement light forms a predetermined width D1 in the Y-axis direction, but the measurement light may form a columnar shape having a width D1 as a diameter.

As shown in FIG. 8, the measurement light for the predetermined width D2 of the width D1 is shielded by the sponge 20, and the remaining measurement light not shaded by the sponge 20 is received by the light receiving unit 51. Then, the light receiving unit 51 that receives the measurement light sends information on the amount of light received to the determination means 5A.

A light receiving amount value V1 as a threshold value is set in advance in the determination means 5A in order to determine whether or not the sponge 20 is in a washable state, and the determination means 5A is sent from the light receiving unit 51. It is determined whether the light receiving amount value V2 is larger than the light receiving amount value V1 or is equal to or less than the light receiving amount value V1. As shown in the graph G1 of FIG. 9, since the light receiving amount value V2 is smaller than the light receiving amount value V1, the determination means 5A determines that the sponge 20 is in a state where the outer peripheral edge Wd of the wafer W can be washed. do. That is, it is determined that the sponge 20 is not consumed and that the sponge 20 has sufficiently swelled due to the absorption of the washing water. In the graph G1 of FIG. 9, the horizontal axis represents time, for example, and the vertical axis represents the received light amount value.

FIG. 10 shows a case where the sponge 20 is worn out or the sponge 20 does not swell sufficiently even if it absorbs the washing water. Assuming that the diameter of the sponge 20 in this case is the diameter R2, the diameter R2 is smaller than the diameter R1 of the sponge 20 shown in FIG. The light emitting unit 50 projects the measurement light in a straight line in the X-axis direction toward the light receiving unit 51 while maintaining a predetermined width D1 in the Y-axis direction. In FIG. 10, only the sponge 20, the determining means 5A, the light emitting unit 50, and the light receiving unit 51 are shown, and the other components of the wafer cleaning device 1 are omitted.

As shown in FIG. 10, the measurement light for the predetermined width D3 of the width D1 is shielded by the sponge 20, and the remaining measurement light not shaded by the sponge 20 is received by the light receiving unit 51. The amount of measurement light shaded by the sponge 20 having a diameter of R2 shown in FIG. 10 is smaller than the amount of measurement light shaded by the sponge 20 having a diameter R1 shown in FIG. The light receiving unit 51 that has received the measurement light sends information on the light receiving amount (for example, the light receiving amount V3) to the determination means 5A.

The determination means 5A determines whether the light receiving amount value V3 is larger than the light receiving amount value V1 or is equal to or less than the light receiving amount value V1. As shown in the graph G2 of FIG. 11, since the light receiving amount value V3 is a value larger than the light receiving amount value V1, the determination means 5A determines that the sponge 20 is in a state where the outer peripheral edge Wd of the wafer W cannot be washed. to decide. That is, it is determined that the sponge 20 is exhausted, or that the sponge 20 does not swell sufficiently even if it absorbs the washing water. In the graph G2 of FIG. 11, the horizontal axis represents time, for example, and the vertical axis represents the received light amount value.

When the determination means 5A determines that the sponge 20 is in a state in which it cannot be washed, the determination means 5A notifies the operator of the determination by sounding an alarm sound or displaying an error. Then, the cleaning water nozzle 29 shown in FIG. 6 supplies the cleaning water again to the sponge 20 determined to be uncleanable for a predetermined time. It was determined that the sponge 20 was not sufficiently inflated due to insufficient supply of the washing water and could not be washed, or that the sponge 20 had already been consumed and could not be washed. It is carried out to determine whether or not. After that, in the same manner as described above, the determination means 5A again determines whether or not the sponge 20 is in a state where the outer peripheral edge Wd of the wafer W can be washed, and when it is determined again that the sponge 20 cannot be washed. , The sponge 20 is replaced as being worn.

For example, as shown in FIG. 12, even when the cleaning means 2 is configured to include a plurality of sponges in the cleaning box 21, the determination means 5A determines only one sponge 20 by the cleaning means 2. It is performed in the same manner as when the configuration is provided.
As shown in FIG. 12, the cleaning means 2 may include, for example, two sponges 20A and sponges 20B in the cleaning box 21. The roll-shaped sponge 20A and the sponge 20B are individually rotatably and hollowly supported by the sponge rotating means 22. Further, the sponge 20A and the sponge 20B are oriented in the X-axis direction in the cleaning box 21 so that their longitudinal directions are approximately opposite to each other, that is, they intersect at a predetermined angle when viewed from the X-axis direction. In parallel with. The sponge 20A serves as a sponge for cleaning the outer peripheral edge Wd on the other surface Wb side of the wafer W, and the sponge 20B serves as a sponge for cleaning the outer peripheral edge Wd on the one surface Wa side of the wafer W. Further, when cleaning the outer peripheral edge Wd of the wafer W, the sponge 20A and the sponge 20B rotate in opposite directions.

In FIG. 12, by positioning the holding table 30 at the position Y1, it is possible to determine whether or not the sponge 20A and the sponge 20B are in a state where the outer peripheral edge Wd of the wafer W can be washed by the determination means 5A. ing. Further, the supply of the washing water from the washing water nozzle 29 to the sponge 20 has already been performed.

The determination by the determining means 5A as to whether or not the sponge 20A and the sponge 20B are in a state where the outer peripheral edge Wd of the wafer W can be washed is carried out, for example, as described below. FIG. 13 shows a case where both the sponge 20A and the sponge 20B are not consumed, and both the sponge 20A and the sponge 20B sufficiently swell and have elasticity due to the absorption of the washing water. There is. FIG. 14 shows a case where the sponge 20A is worn out or not sufficiently inflated, and the sponge 20B is not worn out and is sufficiently inflated. FIG. 15 shows a case where the sponge 20B is worn or not sufficiently inflated, and the sponge 20A is not worn and is sufficiently inflated.
In any of the cases shown in FIGS. 13 to 15, the light emitting unit 50 keeps the width of the measurement light constant in the Y-axis direction and + X toward the light receiving unit 51 (not shown in FIGS. 13 to 15). Project in a straight line in the direction.

As shown in FIG. 13, when both the sponge 20A and the sponge 20B are not consumed and both are sufficiently inflated, the amount of measurement light shielded by the sponge 20A and the sponge 20B is reduced. , The amount of light received by the light receiving unit 51 is smaller than that shown in FIG. 14 and FIG. Therefore, the determination means 5A determines that the light receiving amount value of the light receiving unit 51 is equal to or less than a preset threshold value (light receiving amount value), and the sponge 20A and the sponge 20B clean the outer peripheral edge Wd of the wafer W. Judge that it is in a possible state.
On the other hand, when the sponge 20A is worn or not sufficiently inflated as shown in FIG. 14, or when the sponge 20B is worn or not sufficiently inflated as shown in FIG. 15, the light receiving portion 51 Since the light receiving amount becomes large, the determination means 5A determines that the light receiving amount value of the light receiving unit 51 is larger than the preset threshold value (light receiving amount value), and the sponge 20A or the sponge 20B is the outer peripheral edge of the wafer W. It is determined that Wd is in a state where it cannot be washed.

The case where the cleaning means 2 includes only one sponge 20 in the cleaning box 21 will be described again. As described above, when the determination means 5A determines that the sponge 20 is in a washable state as shown in FIG. 8, the holding table 30 in which the moving means 4 is located at the position Y1 is determined as shown in FIG. Is moved in the + Y direction. Then, the holding table 30 stops at a predetermined position Y2 in the Y-axis direction under the position detection by the Y-axis direction position detecting means 45 and the control by the control means 19. As a result, the outer peripheral edge Wd of the wafer W comes into contact with the outer surface of the sponge 20 which is not consumed and has sufficient elasticity due to absorption of the washing water. The sponge 20 can be easily deformed, and the outer peripheral edge Wd of the wafer W may be in a state of biting into the outer surface of the sponge 20.

With the outer peripheral edge Wd of the wafer W in contact with the outer surface of the sponge 20, the sponge rotating means 22 rotates the sponge 20 in the counterclockwise direction when viewed from the + Z direction side. Further, when the rotating means 31 rotates the holding table 30 in the clockwise direction when viewed from the + Z direction side, the sponge 20 wipes off the resin left on the outer peripheral edge Wd of the wafer W, and the entire circumference of the outer peripheral edge Wd. Will be washed. Further, the washing water is supplied from the washing water nozzle 29 to the sponge 20.

During the above cleaning, the air curtain forming means 24 ejects compressed air from the vertical direction toward the wafer W that has entered the wafer advance inlet 212a, so that the thin film-like air covering a half of the wafer advance inlet 212a is covered. Generates a flow (air curtain). During cleaning of the outer peripheral edge Wd of the wafer W, the cleaning water supplied from the cleaning water nozzle 29 and absorbed by the sponge 20 flows out from the sponge 20 and flows through one surface Wa and the other surface Wb of the rotating wafer W. To go. Since the wafer entrance 212a is covered with an air curtain, the washing water does not scatter from the wafer entrance 212a to the outside of the cleaning box 21.

As the outer peripheral edge Wd of the wafer W is washed, the washing water supplied from the washing water nozzle 29 and absorbed by the sponge 20 exudes from the sponge 20 and falls and accumulates on the bottom plate 211. Then, the tilting means 10 operates in order to drain the washing water from the drain port 211b of the washing box 21. That is, as shown in FIG. 17, the motor 101 rotates the rotating shaft 100 in the counterclockwise direction when viewed from the −X direction side (the front side of the paper surface in FIG. 17), so that the connecting member 102 is rotated along with the rotation of the rotating shaft 100. Tilts, and the holding means 3 on the guide rail 41 and the cleaning means 2 connected to one end of the guide rail 41 are tilted in the same manner as the connecting member 102. As a result, the cleaning water accumulated on the bottom plate 211 of the cleaning box 21 is drained from the drain port 211b to a wastewater tank or the like outside the cleaning box 21.

As described above, the outer peripheral edge Wd of the waiha W is washed, and after the resin left on the outer peripheral edge Wd of the waha W is washed and removed, the holding table 30 is rotated, the sponge 20 is rotated, and the washing water is washed. The supply of washing water from the nozzle 29 to the sponge 20 is stopped, and the holding means 3 and the washing means 2 in the tilted state are returned to the non-tilted state. Further, the moving means 4 moves the holding table 30 located at the position Y2 toward the −Y direction and returns it to the origin position.

The waiha cleaning device 1 of the first embodiment according to the present invention has a holding means 3 having a holding surface 300a for holding the waha W and an outer surface of a roll-shaped sponge 20 on the outer peripheral edge Wd of the waha W held by the holding means 3. Cleaning means 2 for cleaning the outer peripheral edge Wd of the wafer W, moving means 4 for relatively approaching or separating the holding means 3 and cleaning means 2 in the direction of the holding surface of the holding means 3, and sponge 20 for cleaning. The cleaning water nozzle 29 for supplying water and the determining means 5A for determining whether or not the sponge 20 is in a washable state are provided, and the holding means 3 protrudes the outer peripheral portion of the wafer W and holds the central portion on the holding surface 300a. A holding table 30 for sucking and holding the holding table 30 and a rotating means 31 for rotating the holding table 30 about the center of the holding surface 300a. The light receiving unit 51 is provided with a light receiving unit 51 that receives light, and the measurement light has a width. 5A determines that the sponge 20 cannot be washed if the light receiving amount of the light receiving unit 51 is larger than the preset light receiving amount, and determines that the sponge 20 can be washed if the light receiving amount of the light receiving unit 51 is equal to or less than the preset light receiving amount. Then, the determination is made in a state where the holding means 3 and the cleaning means 2 are separated from a predetermined distance at which the sponge 20 comes into contact with the outer peripheral edge Wd of the wafer W. Therefore, the sponge 20 is worn out and becomes smaller, or the sponge 20 to which the washing water is supplied is not sufficiently inflated and has no elasticity (dry and hard state). As a result, the determination means 5A can determine when the outer peripheral edge Wd of the wafer W cannot be sufficiently contacted and the cleaning becomes insufficient before the start of cleaning. Then, when the determination means 5A determines that the cleaning means can be cleaned, the holding means 3 and the cleaning means 2 are positioned at predetermined positions, and the outer peripheral edge Wd of the wafer W held by the holding means 3 is brought into contact with the outer surface of the sponge 20 to bring the wafer W into contact. Since the outer peripheral edge Wd is cleaned, it is possible to appropriately clean the outer peripheral edge Wd of the wafer W for each wafer W.

Since the light emitting unit 50 and the light receiving unit 51 are arranged in the holding means 3, the holding means 3 is positioned at a predetermined position to determine whether or not the sponge 20 is in a washable state. The means 5A can be put into a state where it can be performed.

(5) First Spin Cleaning Step for Cleaning the entire Surface of the Wafer The wafer W whose outer peripheral edge Wd has been cleaned is conveyed from the wafer cleaning device 1 shown in FIG. 17 to the spinner cleaning device 96 shown in FIG. The spinner cleaning device 96 is a single-wafer cleaning device, and includes a holding means 960 for holding the wafer W, a rotating means 961 for rotating the holding means 960, and a cleaning nozzle 962 for injecting cleaning water onto the wafer W. , Is equipped.

The holding means 960, for example, has a circular outer shape and sucks and holds the wafer W on a holding surface 960a communicating with a suction source (not shown). The holding means 960 is housed inside a bottomed cylindrical cleaning housing 963 with a circular opening at the top. In FIG. 18, a part of the side wall of the cleaning housing 963 is cut out so that the inside can be grasped.

The rotating means 961 composed of a motor or the like (not shown) is arranged below the holding means 960, and the holding means 960 can be rotated around the axis in the Z-axis direction.
The cleaning nozzle 962 arranged above the holding means 960 can be reciprocated in the radial direction of the holding means 960 by the moving means 964, and cleaning water such as pure water is used toward the holding surface 960a of the holding means 960. Can be sprayed. The cleaning nozzle 962 may be able to swivel and move around the axis in the Z-axis direction at a predetermined angle above the holding means 960.

The wafer W is conveyed onto the holding means 960, placed on the holding surface 960a so that the other surface Wb is on the upper side, and the holding means 960 sucks and holds the wafer W on the holding surface 960a.
Next, the cleaning water is ejected from the cleaning nozzle 962 toward the other surface Wb of the wafer W, and the moving means 964 reciprocates the cleaning nozzle 962 in the radial direction of the holding means 960. Further, when the rotating means 961 rotates the holding means 960, the wafer W held by the holding means 960 also rotates, so that the entire surface Wb of the other surface Wb of the wafer W is washed.

After the other surface Wb of the wafer W is washed for a predetermined time, the wafer W is suction-held on the holding surface 960a of the holding means 960 with one surface Wa facing up. Then, the entire surface of one surface Wa of the wafer W is washed with the washing water in the same manner as the other surface Wb is washed.

(6) Second Grinding Step for Grinding One Surface of a Wafer with a Grinding Wheel The wafer W whose one surface Wa and the other surface Wb have been cleaned is, for example, conveyed to a tape mounter (not shown) and used by a pressing roller or the like. A protective tape is attached to the other surface Wb, which is a flat surface. The wafer W to which the protective tape is attached to the other surface Wb is suction-held on the holding surface of the chuck table 940 of the grinding device 94 shown in FIG. 5, and one surface Wa on which the undulation of the wafer W remains is the grinding wheel 941a. Grinded by. Then, one surface Wa of the wafer W is ground by a predetermined amount to remove waviness, and the second grinding step is completed.

(7) Second Spin Cleaning Step for Cleaning the entire Surface of the Wafer The wafer W on which one surface Wa has been ground is transported to the single-wafer spinner cleaning device 96 shown in FIG. 18, and is subjected to the first spin cleaning step. Similarly, one surface Wa and the other surface Wb are washed.

The configuration of the wafer cleaning device 1 of the first embodiment is not limited to the example described above, and can be appropriately changed within the range in which the effects of the present invention can be exhibited.
As shown in FIGS. 1 and 2, the wafer cleaning device 1 may include, for example, a first storage unit 54 and a third determination means 5C. The first storage unit 54 is electrically connected to the determination means 5A, and stores the amount of light received by the light receiving unit 51 when the determination means 5A determines that the sponge 20 can be washed. The third determination means 5C is electrically connected to the determination means 5A and the first storage unit 54.

For example, when the outer peripheral edge cleaning step of (4) cleaning the outer peripheral edge of the wafer described above is continuously performed for a plurality of wafers W, the first storage unit 54 and the third determination means 5C operate. do. When one wafer W (hereinafter referred to as the wafer W washed immediately before) was washed, the first storage unit 54 of the light receiving unit 51 determined by the determination means 5A that the sponge 20 could be washed. The light receiving amount V4 (hereinafter referred to as the light receiving amount V4 of the immediately preceding time) is stored.

Before the sponge 20 starts cleaning the outer peripheral edge Wd of the next waiha W (hereinafter referred to as the waha W this time), a predetermined amount of cleaning water is supplied from the cleaning water nozzle 29 to the sponge 20 and the holding table 30 is set. It is assumed that the sponge 20 is determined to be washable by the determination means 5A after being positioned at a predetermined position. Then, this time, the light receiving amount of the light receiving portion 51 when the determination means 5A determines that the sponge 20 can be washed is set as the light receiving amount V5 (hereinafter, referred to as the light receiving amount V5 this time).

When cleaning the wafer W this time, even if the determination means 5A determines that the sponge 20 can be washed, the degree of expansion (degree of drying) of the sponge 20 is the temperature inside the cleaning box 21. Depending on various factors such as the cleaning time of the wafer W in the previous round and the cleaning time of the wafer W in the previous round, the previous round and this time may differ. Therefore, the sponge 20 may not swell sufficiently as compared with the case where the wafer W was washed immediately before, and may be in an inappropriate state for cleaning the outer peripheral edge Wd of the wafer W. Therefore, the third determination means 5C further determines whether or not the sponge 20 is in a washable state.

As described above, after the determination by the determination means 5A is made, the information about the received light amount V5 is sent to the third determination means 5C. The third determination means 5C extracts data about the light receiving amount V4 of the immediately preceding time from the first storage unit 54, and calculates the difference = difference V6 between the light receiving amount V5 of this time and the light receiving amount V4 of the immediately preceding time. In the third determination means 5C, in order to determine whether or not the sponge 20 is in a washable state, a difference V7 between the amount of light received this time and the amount of light received immediately before is set in advance as a threshold value. The third determination means 5C determines that the sponge 20 cannot be washed when the difference V6 is larger than the predetermined threshold value V7, that is, the sponge 20 is still in a dry state, and the difference V6 is When the difference is V7 or less set in advance, it is determined that the sponge 20 is swollen to a state where it can be washed. In this way, when the outer peripheral edge cleaning step is continuously performed on a plurality of wafers W, it is further determined by the third determination means 5C whether or not the sponge 20 is not dried and can be cleaned. can do. Further, when the judgment is made only by the judgment means 5A, a difference occurs depending on the degree of expansion of the sponge 20 between the cleaning of the outer peripheral edge Wd of the wafer W immediately before and the cleaning of the outer peripheral edge Wd of the wafer W this time. However, the difference can be reduced by making a judgment by the third judgment means 5C in addition to the judgment by the judgment means 5A.
When the outer peripheral edge cleaning step is continuously performed on a plurality of wafers W, the outer peripheral edge Wd of the current wafer W is cleaned immediately after the outer peripheral edge Wd of the wafer W is cleaned immediately before. In this case, when cleaning the outer peripheral edge Wd of the wafer W immediately before in the morning time zone and then in the afternoon time zone several hours later, or immediately before the cleaning of the outer peripheral edge Wd of the wafer W this time. This is the case where the cleaning of the outer peripheral edge Wd of the wafer W is different from the cleaning of the outer peripheral edge Wd of the wafer W this time.

When the third determination means 5C determines that the sponge 20 is in a state where the outer peripheral edge Wd of the wafer W can be washed, the moving means 4 moves the holding table 30 to move the outer peripheral edge Wd of the wafer W. Is brought into contact with the sponge 20, and then washing is started.

(Embodiment 2 of Wafer Cleaning Device)
The wafer cleaning device 1A shown in FIG. 19 includes a second determination means 5B in place of the determination means 5A of the wafer cleaning device 1 shown in FIG. 1, and a second storage unit 54 in place of the first storage unit 54 shown in FIG. A storage unit 55 is provided, and a fourth determination means 5D is provided in place of the third determination means 5C shown in FIG. Other configurations of the wafer cleaning device 1A are the same as those of the wafer cleaning device 1 shown in FIG.

As shown in FIG. 20, the second determination means 5B is connected to the light receiving unit 51, and the light receiving unit 51 sends a detection signal based on the received light amount to the second determination unit 5B. The second storage unit 55 is electrically connected to the second determination means 5B, and stores the amount of light received by the light receiving unit 51 when the second determination means 5B determines that the sponge 20 can be washed. The fourth determination means 5D is electrically connected to the second determination means 5B and the second storage unit 55.

The operation of the wafer cleaning device 1A when the outer peripheral edge Wd of the wafer W is cleaned by using the wafer cleaning device 1A will be described below.
The wafer W is placed on the holding surface 300a by the conveying means 18 that sucks and holds the wafer W shown in FIG. 19, and the holding table 30 causes the outer peripheral portion Wd of the wafer W to protrude from the holding surface 300a and pushes the central portion of the wafer W. It is sucked and held by the holding surface 300a.

A predetermined amount of washing water is supplied to the sponge 20 from the washing water nozzle 29, and the sponge 20 is prepared to swell by absorbing the washing water and to have elasticity. After a predetermined amount of washing water is supplied to the sponge 20 from the washing water nozzle 29, the supply of washing water is stopped.

As shown in FIGS. 21 and 22, the moving means 4 moves the holding table 30 holding the wafer W in the + Y direction. When the movement of the holding table 30 is started, the light projecting unit 50 + X toward the light receiving unit 51, as shown in FIG. 22, measuring light having a constant width (for example, width D1) in the Y-axis direction. Start projecting in a straight line in the direction.

When the moving means 4 moves the holding table 30 holding the wafer W in the + Y direction, the holding means 3 and the cleaning means 2 start to approach each other. Then, the measurement light emitted from the light projecting unit 50 in the + X direction passes through the wafer entrance 212a of the cleaning box 21 of the cleaning means 2, and a part of the measurement light is shielded by the sponge 20 and is shielded by the light receiving unit 51. It will be in a state of receiving light. That is, as the holding table 30 moves in the + Y direction, the amount of light received by the light receiving unit 51 gradually decreases. Further, the light receiving unit 51 sequentially sends information about the light receiving amount value to the second determining means 5B, and the second determining means 5B starts monitoring the received light amount value.

The second determination means 5B includes a light receiving amount monitoring unit (not shown), and the light receiving amount monitoring unit has a light receiving amount value as a threshold value for determining whether or not the sponge 20 is in a washable state. V8 is set, and the light receiving amount monitoring unit performs monitoring until the light receiving amount value of the light receiving unit 51 decreases and reaches the light receiving amount value V8. When the light receiving amount value of the light receiving unit 51 becomes the light receiving amount value V8 by further moving the holding table 30 in the + Y direction, the moving means 4 stops the movement of the holding table 30.

Next, the position of the stopped holding table 30 in the Y-axis direction (for example, the position Y3) is detected by the Y-axis direction position detecting means 45. Further, the distance L3 between the position Y3 of the holding table 30 and the cleaning means 2 in the Y-axis direction is measured, and information about the distance L3 is sent to the second determination means 5B. The second determination means 5B has a predetermined distance Lc in the Y-axis direction between the holding means 3 and the cleaning means 2 in advance as a threshold for determining whether or not the sponge 20 is in a washable state. The second determination means 5B is set, and the sponge 20 is not cleaned if the distance L3 between the holding means 3 and the cleaning means 2 is closer than the predetermined distance Lc from the information about the sent distance L3. Judge that it is in a possible state. This is because the sponge 20 is exhausted, or the sponge 20 does not swell sufficiently even if it absorbs the washing water, that is, the sponge 20 does not have a sufficient diameter for washing, so that the holding table 30 is held. This is because it can be determined that the outer peripheral edge Wd of the wafer W cannot be brought into contact with the sponge 20 unless it is brought closer to the sponge 20 beyond a predetermined distance Lc.
On the other hand, the second determining means 5B determines that the sponge 20 is in a washable state when the distance L3 between the holding means 3 and the cleaning means 2 is a predetermined distance Lc or more.

When the second determination means 5B determines that the sponge 20 cannot be washed, the second determination means 5B notifies the operator of the determination by an alarm sound, an error display, or the like. Then, the cleaning water nozzle 29 shown in FIG. 21 supplies the cleaning water again to the sponge 20 determined to be uncleanable for a predetermined time. It was determined that the sponge 20 was not sufficiently inflated due to insufficient supply of the washing water and could not be washed, or that the sponge 20 had already been consumed and could not be washed. It is carried out to determine whether or not. Then, in the same manner as described above, the second determination means 5B again determines whether or not the sponge 20 is in a state where the outer peripheral edge Wd of the wafer W can be washed, and the determination that the sponge 20 cannot be washed is made again. In that case, the sponge 20 is determined to be worn and replaced.

When the second determining means 5B determines that the sponge 20 is in a washable state, the moving means 4 moves the holding table 30 located at the position Y3 in the + Y direction. Then, as shown in FIG. 23, the holding table 30 stopped at a predetermined position Y4 in the Y-axis direction under the position detection by the Y-axis direction position detecting means 45 and the control by the control means 19, and absorbed the washing water. As a result, the outer peripheral edge Wd of the waiha W comes into contact with the outer surface of the sponge 20 which is sufficiently swelled and has elasticity.

The sponge rotating means 22 rotates the sponge 20 and the rotating means 31 rotates the holding table 30 in a state where the outer peripheral edge Wd of the wafer W held by the holding table 30 is in contact with the outer surface of the sponge 20. The sponge 20 wipes off the resin left on the outer peripheral edge Wd of the weight W, and the entire circumference of the outer peripheral edge Wd is washed. During cleaning, cleaning water is supplied from the cleaning water nozzle 29 to the sponge 20, and the air curtain forming means 24 forms the air curtain. Further, the cleaning box 21 is tilted at a predetermined angle by the tilting means 10, so that the cleaning water collected on the bottom plate 211 of the cleaning box 21 is drained from the drain port 211b to a wastewater tank or the like outside the cleaning box 21.

After the resin left on the outer peripheral edge Wd of the weight W is washed and removed, the rotation of the holding table 30, the rotation of the sponge 20, and the supply of washing water from the washing water nozzle 29 to the sponge 20 are stopped, and further. , The holding means 3 and the cleaning means 2 in the tilted state are returned to the non-tilted state. Further, the moving means 4 moves the holding table 30 located at the position Y4 toward the −Y direction and returns it to the origin position.

As described above, in the wafer cleaning device 1A of the second embodiment according to the present invention, the holding means 3 and the cleaning means 2 are held by the moving means 4 so that the light receiving amount of the light receiving unit 51 becomes a predetermined predetermined light receiving amount. A second determination means 5B for determining whether or not the sponge 20 is in a washable state based on the distance between the holding means 3 and the cleaning means 2 is provided in place of the determination means 5A, and the second determination means 5B is provided. If the distance between the holding means 3 and the cleaning means 2 is closer than a predetermined distance, it can be determined that cleaning is not possible, and if it is separated by a predetermined distance or more, it can be determined that cleaning is possible. Therefore, the sponge 20 is worn out and becomes smaller, or the sponge 20 to which the washing water is supplied is not sufficiently inflated and has no elasticity (dry and hard state). As a result, when the sponge 20 cannot be sufficiently brought into contact with the outer peripheral edge Wd of the wafer W and the cleaning becomes insufficient, the second determination means 5B can determine before the start of cleaning.

Since the light emitting unit 50 and the light receiving unit 51 are arranged in the holding means 3, the holding means 3 is moved by the moving means 4, so that the light emitting unit 50 and the light receiving unit 51 are moved in conjunction with each other. Therefore, it is possible to efficiently make a judgment by the second judgment means 5B.

The second storage unit 55 and the fourth determination means 5D of the wafer cleaning device 1A shown in FIG. 19 operate, for example, when cleaning the outer peripheral edge Wd of a plurality of wafers W in succession. When one waha W (hereinafter referred to as the waha W washed immediately before) is washed, the second storage unit 55 determines that the sponge 20 can be washed by the second determination means 5B. The distance L4 in the Y-axis direction between the holding means 3 and the cleaning means 2 (hereinafter referred to as the immediately preceding distance L4) is stored.

In the outer peripheral edge cleaning step on the second day, cleaning water is applied from the cleaning water nozzle 29 to the sponge 20 before the cleaning of the outer peripheral edge Wd of the 51st waiha W (hereinafter referred to as the waha W this time) is started. It is assumed that a predetermined amount is supplied, the holding table 30 is brought close to the cleaning means 2, and the second determining means 5B again determines that the sponge 20 can be washed. Then, this time, the distance in the Y-axis direction between the holding means 3 and the cleaning means 2 when the second determining means 5B determines that the sponge 20 can be washed is defined as the distance L5 (hereinafter, the distance L5 this time). do).

When cleaning the wafer W this time, even if the second determination means 5B determines that the sponge 20 can be washed, the degree of expansion (degree of drying) of the sponge 20 is the cleaning box 21. Depending on various factors such as the temperature inside and the cleaning time of the wafer W in the previous round, the previous round and this time may differ. Therefore, the sponge 20 may not swell sufficiently as compared with the case where the wafer W was washed immediately before, and may be in an inappropriate state for cleaning the outer peripheral edge Wd of the wafer W. Therefore, the fourth determination means 5D further determines whether or not the sponge 20 is in a washable state.

As described above, after the judgment by the second judgment means 5B is made, the information about the current distance L5 is sent to the fourth judgment means 5D. The fourth determination means 5D extracts data about the distance L4 of the previous round from the second storage unit 55, and calculates the difference = difference L6 between the distance L5 of this time and the distance L4 of the previous round. In the fourth determination means 5D, in order to determine whether or not the sponge 20 is in a washable state, the difference L7 between the current distance and the immediately preceding distance is set in advance as a threshold value. The determination means 5D of 4 determines that the sponge 20 cannot be washed when the difference L6 is larger than the preset difference L7, that is, the sponge 20 is still in a dry state, and the difference L6 is equal to or less than the preset difference L7. In some cases, it is determined that the sponge 20 is swollen to a state where it can be washed. In this way, when the outer peripheral edge cleaning step is continuously performed on a plurality of wafers W, it is more certain that the sponge 20 is not dried and can be cleaned by the fourth determination means 5D. Can be judged. Further, when only the judgment by the second judgment means 5B is performed, it depends on the degree of expansion of the sponge 20 between the cleaning of the outer peripheral edge Wd of the wafer W immediately before and the cleaning of the outer peripheral edge Wd of the wafer W this time. A difference may occur, but the difference can be reduced by making a judgment by the fourth judgment means 5D in addition to the judgment by the second judgment means 5B.

When the fourth determination means 5D determines that the sponge 20 is in a state where the outer peripheral edge Wd of the wafer W can be washed, the moving means 4 moves the holding table 30 to move the outer peripheral edge Wd of the wafer W. Is brought into contact with the sponge 20, and then washing is started.

1: Wafer cleaning device
10: Tilt means 100: Spindle 101: Motor 102: Connecting member 18: Conveying means 180: Suction pad 181: Arm 19: Control means 3: Holding means 30: Holding table 300: Suction part 300a: Holding surface 301: Frame 31 : Rotating means 310: Rotating shaft 311: Motor 34: Movable block 35A, 35B: Support bar 2: Cleaning means 20: Sponge 21: Cleaning box 210: Top plate 210a: Exhaust port 211: Bottom plate 211b: Drain port 212: Side wall 212a : Weha entrance
22: Sponge rotating means 220: Rotating shaft 221: Motor 24: Air curtain forming means 29: Washing water nozzle 4: Moving means 40: Ball screw 41: Guide rail 42: Motor 45: Y-axis direction position detecting means 450: Scale 451: Reading unit 5A: Judgment means 50: Light emitting unit 51: Light receiving unit 54: First storage unit 5C: Third determination means 90 Holding table 90a: Holding surface 91: Resin supply device 92: Holding means 93: Ultraviolet irradiation mechanism 94: Grinding device 940: Chuck table 941: Grinding wheel 941a: Grinding grindstone 96: Spinner cleaning device 960: Holding means 961: Rotating means 962: Cleaning nozzle 963: Cleaning housing 964: Moving means W: Waha Wa: One of the waha Surface Wb: The other surface of the waiha Wd: The outer peripheral edge of the waiha
S: Protective member S1: Resin S2: Film S2a: Overhang
1A: Wafer cleaning device 5B: Second judgment means 55: Second storage unit 5D: Fourth judgment means

Claims (5)

A wafer cleaning device that cleans the outer periphery of a wafer.
A holding means having a holding surface for holding the waha, a cleaning means for cleaning the outer peripheral edge of the waiha by bringing the outer surface of the roll-shaped sponge into contact with the outer peripheral edge of the waha held by the holding means, and a holding surface of the holding means. A moving means for relatively approaching or separating the holding means and the cleaning means in the direction, a cleaning water nozzle for supplying cleaning water to the sponge, and a determining means for determining whether or not the sponge is in a washable state. And with
The holding means includes a holding table that protrudes from the outer peripheral portion of the wafer and sucks and holds the central portion on the holding surface, and a rotating means that rotates the holding table around the center of the holding surface.
It is provided with a light projecting unit that emits measurement light and a light receiving unit that receives the measurement light across the sponge, and the measurement light has a width, and a predetermined width of the width is shielded by the sponge. The light receiving unit receives the measurement light that is not shielded by the sponge.
The determination means determines that the sponge cannot be washed if the light receiving amount of the light receiving portion is larger than the preset light receiving amount, and the sponge can be washed if the light receiving amount of the light receiving portion is equal to or less than the preset light receiving amount. Judging that
The determination means makes a determination in a state where the holding means and the cleaning means are separated from the outer peripheral edge of the wafer by a predetermined distance from which the sponge comes into contact.
When the determination means determines that cleaning is possible, the holding means and the cleaning means are positioned at predetermined positions, and the outer peripheral edge of the wafer held by the holding means is brought into contact with the outer surface of the sponge to clean the outer peripheral edge of the wafer. Wafer cleaning device. The wafer cleaning device according to claim 1, wherein the light emitting unit and the light receiving unit are arranged in the holding means. The holding means and the cleaning means are brought close to each other by the moving means so that the light receiving amount of the light receiving portion becomes a predetermined predetermined light receiving amount, and the sponge can be washed by the distance between the holding means and the cleaning means. A second determination means for determining whether or not the condition is in the above-mentioned determination means is provided in place of the determination means.
The second determination means determines that cleaning is not possible if the distance between the holding means and the cleaning means is closer than a predetermined distance, and determines that cleaning is possible if the distance is greater than or equal to the predetermined distance. 2. The wafer cleaning device according to 2. Equipped with a first storage unit
The first storage unit stores the amount of light received immediately before the sponge is determined to be washable by the determination means.
A third determination means for determining that cleaning is not possible when the difference between the amount of light received stored by the first storage unit and the amount of light received when the determination means determines that cleaning is possible is greater than a preset difference. The wafer cleaning device according to any one of claims 1 or 2, further provided. Equipped with a second storage unit
The second storage unit stores the distance between the holding means and the cleaning means immediately before the second determination means determines that the sponge can be washed.
The difference between the distance stored by the second storage unit and the distance between the holding means and the cleaning means when the second determination means determines that cleaning is possible is larger than a preset difference. The wafer cleaning device according to claim 3, further comprising a fourth determination means for determining that cleaning is not possible.

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