JP7340968B2 - Semiconductor cleaning equipment and semiconductor cleaning method - Google Patents

Description

The present invention relates to a semiconductor cleaning apparatus and a semiconductor cleaning method for cleaning a rotating semiconductor substrate.

In recent years, device structures of semiconductor devices have become extremely complex due to miniaturization, multilayering, etc. Further, semiconductor devices employ a wide variety of materials, structures with high aspect ratios, and the like, and the manufacturing process is also becoming more complex.

In a series of manufacturing steps of a manufacturing process for a semiconductor substrate having a semiconductor device, a step of cleaning the semiconductor substrate is performed multiple times. Examples of cleaning methods for semiconductor substrates include water cleaning, such as dip cleaning, jet cleaning, mist cleaning, and two-fluid cleaning. Further, as a method for cleaning a semiconductor substrate, there are various methods other than washing with water. Examples of cleaning methods for semiconductor substrates include cleaning with a special chemical, scrub cleaning, and dry cleaning using plasma or dry ice.

Patent Document 1 discloses a configuration (hereinafter also referred to as "related configuration A") for removing particles on a semiconductor substrate as a method for cleaning a semiconductor substrate. Specifically, in related configuration A, a two-fluid nozzle of the cleaning device mixes pressurized gas and a chemical solution to form a mist. Then, the cleaning device performs a process in which the two-fluid nozzle discharges (irradiates) mist onto the semiconductor substrate on which the pattern is formed. In addition, in this specification, the expressions "irradiation", "irradiate", and "irradiated" include the meanings of "hit" and "apply".

JP2008-041931A

In related configuration A, the surface of the semiconductor substrate is cleaned while the support base supporting the semiconductor substrate is rotating. However, in related configuration A, the amount of cleaning material (mist) irradiated onto the surface of the semiconductor substrate per unit time is a predetermined value corresponding to the aspect ratio of the structure (pattern) formed on the surface of the semiconductor substrate. Set. That is, in related configuration A, the amount of cleaning material irradiated onto the surface of the semiconductor substrate per unit time is constant.

Note that as the semiconductor substrate rotates, the structure also rotates. Therefore, if the amount of cleaning material irradiated onto the surface of the semiconductor substrate per unit time is constant, the following problem N may occur depending on the shape or orientation of the rotating structure.

The problem N is, for example, a problem in which a structure is damaged. Furthermore, the problem N is, for example, a problem in which a part of the surface of the semiconductor substrate is not irradiated with the cleaning material. Therefore, it is required to vary the amount of cleaning material irradiated onto the surface of the semiconductor substrate per unit time.

The present invention has been made to solve such problems, and aims to provide a semiconductor cleaning apparatus etc. that can change the amount of cleaning material irradiated onto the surface of a semiconductor substrate per unit time. purpose.

In order to achieve the above object, a semiconductor cleaning apparatus according to one aspect of the present invention cleans a semiconductor substrate having a surface as a surface to be cleaned. The semiconductor cleaning apparatus includes a support base that rotates while supporting the semiconductor substrate, and a cleaning nozzle, and the cleaning nozzle is configured to direct a cleaning material toward the surface of the semiconductor substrate to clean the surface. The semiconductor cleaning device controls the amount of the cleaning material irradiated onto the surface of the semiconductor substrate per unit time in accordance with the rotation of the support base.

According to the present invention, a semiconductor cleaning apparatus includes a support base that rotates while supporting a semiconductor substrate, and a cleaning nozzle. The cleaning nozzle discharges a cleaning material toward the surface of the semiconductor substrate for cleaning the surface. The semiconductor cleaning device controls the amount of the cleaning material irradiated onto the surface of the semiconductor substrate per unit time. Thereby, the amount of cleaning material irradiated onto the surface of the semiconductor substrate per unit time can be changed.

1 is a diagram showing a configuration of a semiconductor cleaning apparatus according to a first embodiment; FIG. 1 is a perspective view showing a cleaning state of the semiconductor cleaning apparatus according to Embodiment 1. FIG. FIG. 3 is a perspective view showing the semiconductor substrate in the state of FIG. 2 rotated 90 degrees counterclockwise or clockwise. FIG. 2 is a cross-sectional view showing a cleaning state of the semiconductor cleaning apparatus according to the first embodiment. 5 is an enlarged view of a portion of FIG. 4. FIG. 7 is a graph showing a characteristic curve showing the relationship between the rotation angle of the semiconductor substrate and the discharge pressure in Embodiment 1. FIG. FIG. 3 is a cross-sectional view of a transistor in configuration A1. FIG. 7 is a cross-sectional view showing a state in which the transistor in configuration A1 is irradiated with a cleaning material. FIG. 3 is a cross-sectional view of a transistor in configuration A2. FIG. 7 is a cross-sectional view showing a state in which a cleaning material is irradiated onto a transistor of configuration A2. 3 is a diagram illustrating a semiconductor cleaning apparatus having a configuration of Modification 1. FIG. 7 is a diagram illustrating a semiconductor cleaning apparatus having a configuration of modification example 2. FIG.

Embodiments will be described below with reference to the drawings. In the following drawings, the same components are given the same reference numerals. The names and functions of the components denoted by the same reference numerals are the same. Therefore, detailed descriptions of some of the components labeled with the same reference numerals may be omitted.

Note that the dimensions, materials, shapes, relative arrangement of each component, etc. illustrated in the embodiments may be changed as appropriate depending on the configuration of the device, various conditions, etc. Further, the dimensions of each component in each figure may differ from the actual dimensions.

<Embodiment 1>
FIG. 1 is a diagram showing the configuration of a semiconductor cleaning apparatus 100 according to the first embodiment. In FIG. 1, the x direction, y direction, and z direction are orthogonal to each other. The x, y and z directions shown in the figures below are also orthogonal to each other. In the following, a direction including the x direction and the direction opposite to the x direction (-x direction) will also be referred to as the "x-axis direction." Further, hereinafter, a direction including the y direction and the direction opposite to the y direction (-y direction) will also be referred to as the "y-axis direction." Furthermore, hereinafter, a direction including the z direction and the direction opposite to the z direction (-z direction) will also be referred to as the "z-axis direction."

Furthermore, hereinafter, a plane including the x-axis direction and the y-axis direction will also be referred to as an "xy plane." Furthermore, hereinafter, a plane including the x-axis direction and the z-axis direction will also be referred to as an "xz plane." Furthermore, hereinafter, a plane including the y-axis direction and the z-axis direction will also be referred to as a "yz plane."

Note that FIG. 1 shows a control section 41 and a drive section 42, which will be described later, for the sake of explanation below. The control section 41 and the drive section 42 are components that are unrelated to the x direction, y direction, and z direction.

Further, in FIG. 1, a rotation axis C1 along the z-axis direction is shown for later explanation. In the following, the state in which the semiconductor cleaning apparatus 100 is cleaning an object to be cleaned is also referred to as a "cleaning state." The object to be cleaned is, for example, the semiconductor substrate 11. The semiconductor cleaning apparatus 100 is an apparatus that cleans a semiconductor substrate 11.

FIG. 2 is a perspective view (bird's view) showing a cleaning state of the semiconductor cleaning apparatus 100 according to the first embodiment. In addition, in FIG. 2, in order to make the configuration easier to understand, a support base 20, a base rotating shaft 24, a control unit 41, and a drive unit 42, which will be described later, are not shown. Further, in FIG. 2, the x direction, y direction, and z direction are shown to make the explanation easier to understand. Note that the x direction and the y direction in FIG. 2 are just examples, and the x direction and the y direction may be replaced with each other.

Referring to FIGS. 1 and 2, semiconductor cleaning apparatus 100 includes a support table 20, a table rotation shaft 24, a cleaning nozzle 30, a control section 41, and a drive section 42. The control unit 41 controls the components within the semiconductor cleaning apparatus 100. Specifically, the control unit 41 controls the cleaning nozzle 30 and the drive unit 42.

The cleaning nozzle 30 has a function of discharging (spraying) the cleaning material 5 under the control of the control unit 41 . The cleaning material 5 is a material for cleaning the surface S1a of the semiconductor substrate 11. The cleaning material 5 is, for example, dry ice. By irradiating the cleaning material 5 onto the surface S1a of the semiconductor substrate 11, foreign matter and the like present on the surface S1a are removed. Note that the cleaning material 5 is not limited to dry ice. The cleaning material 5 may be, for example, water, gas, or the like.

The table rotating shaft 24 is a rod-shaped member. The table rotating shaft 24 is configured to be rotatable. The drive unit 42 is, for example, a motor that rotates the table rotating shaft 24 under the control of the control unit 41.

The support stand 20 has a plate shape. The support stand 20 has a surface 20a. The support stand 20 is configured to be rotatable. Specifically, the support base 20 is connected to a base rotation shaft 24 . Therefore, the support base 20 rotates as the base rotation shaft 24 rotates. Note that the support stand 20 is rotated so that the rotation axis C1 in FIG. 1 becomes the rotation axis of the support stand 20.

The control unit 41 controls the drive unit 42 so that the table rotation shaft 24 rotates. That is, the control unit 41 controls the drive unit 42 so that the support base 20 rotates. The control unit 41 always knows the rotation angle of the table rotation shaft 24 (that is, the rotation angle of the support table 20). The rotation angle of the support base 20 ranges from 0 degrees to 360 degrees.

The rotation speed of the table rotating shaft 24 is set within a predetermined range. The range of the rotational speed of the table rotating shaft 24 is, for example, from 0 to 6000 rpm. In this embodiment, the rotation speed in the cleaning state is set to 15 rpm, for example.

In the cleaning state, the semiconductor substrate 11 is placed on the surface 20a of the support stand 20. The shape of the semiconductor substrate 11 is a plate. Further, the shape of the semiconductor substrate 11 in plan view (XY plane) is, for example, a circle. The semiconductor substrate 11 has a surface S1a as a surface to be cleaned. Surface S1a is the surface of semiconductor substrate 11. A semiconductor device is formed on the surface S1a.

Specifically, in the cleaning state, the semiconductor substrate 11 is fixed to the surface 20a of the support base 20 so that the surface S1a of the semiconductor substrate 11 faces upward. In the cleaning state, the semiconductor substrate 11 rotates as the support base 20 rotates. Note that the semiconductor substrate 11 is fixed to the surface 20a of the support base 20 so that the rotation axis C1 becomes the rotation axis of the rotating semiconductor substrate 11. Therefore, the rotation axis of the rotating semiconductor substrate 11 is the rotation axis C1.

Note that in this embodiment, the semiconductor substrate 11 is fixed to the surface 20a of the support base 20 such that the rotation angle of the semiconductor substrate 11 and the rotation angle of the support base 20 are the same. Therefore, the control unit 41 always knows the rotation angle of the semiconductor substrate 11.

In this embodiment, the semiconductor substrate 11 is fixed to the surface 20a of the support base 20 by a vacuum chuck method. Note that the method for fixing the object to be cleaned (semiconductor substrate 11) is not limited to the vacuum chuck method, and an appropriate method is selected depending on the type of the object to be cleaned. For example, depending on the type of the object to be cleaned, the object to be cleaned may be fixed using a mechanical chuck method.

Further, in the cleaning state, the cleaning nozzle 30 discharges (sprays) the cleaning material 5. Specifically, in the cleaning state, the cleaning nozzle 30 discharges the cleaning material 5 toward the surface S1a of the semiconductor substrate 11. In the following, the process in which the cleaning nozzle 30 discharges the cleaning material 5 toward the surface S1a of the semiconductor substrate 11 is also referred to as a "cleaning process." Further, in the following, the period during which the cleaning process is performed will also be referred to as a "cleaning period".

Furthermore, hereinafter, the angle formed between the surface S1a of the semiconductor substrate 11 and the cleaning nozzle 30 will also be referred to as a "nozzle angle." Furthermore, hereinafter, the distance between the surface S1a of the semiconductor substrate 11 and the cleaning nozzle 30 will also be referred to as a "discharge distance." The nozzle angle and ejection distance are set to predetermined values.

The area on the surface S1a of the semiconductor substrate 11 that is irradiated with the cleaning material 5 can be adjusted by adjusting the nozzle angle, ejection distance, and the like. In this embodiment, the nozzle angle, ejection distance, etc. are set so that about half of the surface S1a of the semiconductor substrate 11 is irradiated with the cleaning material 5.

Furthermore, a plurality of structures X1 are formed on the surface S1a of the semiconductor substrate 11. Each structure X1 is, for example, a device pattern. The shape of each structure X1 is elongated. In addition, in FIG. 2, the longitudinal direction of each structure X1 is the y-axis direction.

In the present embodiment, the ratio between the long side of an elongated member and the short side of the member is also referred to as "aspect ratio." Each structure X1 is a member having a high aspect ratio.

Referring to FIG. 2, the plurality of structures X1 are arranged at intervals. Further, the plurality of structures X1 are arranged so that the longitudinal directions of the plurality of structures X1 are parallel to each other. Note that the number of structures X1 formed on the surface S1a of the semiconductor substrate 11 is not limited to a plurality, and may be one. In the following, the region of the structure X1 to which the cleaning material 5 is irradiated is also referred to as the "cleaning target region."

The rotation angle of the semiconductor substrate 11 is defined, for example, by the orientation of the structure X1 on the semiconductor substrate 11. For example, FIG. 2 shows the configuration of the semiconductor substrate 11 in a situation where the rotation angle of the semiconductor substrate 11 is 180 degrees or 0 degrees.

In the following, the direction in which the cleaning material 5 faces the structure X1 during the cleaning period will also be referred to as the "cleaning direction." The cleaning direction in FIG. 2 is, for example, the x-axis direction. Moreover, in FIG. 2, the longitudinal direction of each structure X1 is the y-axis direction.

FIG. 2 shows a state in which the cleaning direction intersects the longitudinal direction of the structure X1 in plan view (xy plane). Specifically, in FIG. 2, the cleaning direction and the longitudinal direction of the structure X1 are orthogonal.

FIG. 3 is a perspective view (bird's view) showing a state in which the semiconductor substrate 11 (support stand 20) in the state shown in FIG. 2 is rotated 90 degrees counterclockwise or clockwise. In addition, in FIG. 3, the support stand 20, the stand rotating shaft 24, the control part 41, and the drive part 42 are not shown in order to make a structure easy to understand. Moreover, in FIG. 3, the longitudinal direction of each structure X1 is the x-axis direction. Further, FIG. 3 shows the configuration of the semiconductor substrate 11 in a situation where the rotation angle of the semiconductor substrate 11 is 90 degrees or 270 degrees.

FIG. 3 shows a state in which the cleaning direction (x-axis direction) does not intersect with the longitudinal direction (x-axis direction) of the structure X1. Specifically, FIG. 3 shows a state in which the cleaning direction and the longitudinal direction of the structure X1 are parallel.

In the following, a region of the structure X1 that has low resistance to external forces is also referred to as a "low resistance region." Further, in the following, a region of the structure X1 that has high resistance to external forces is also referred to as a "high resistance region."

Note that, as shown in FIGS. 2 and 3, the aspect ratio of the structure X1 is large. The structure X1 with a large aspect ratio has a low resistance region and a high resistance region. The state shown in FIG. 2 is a state in which the cleaning material 5 is irradiated onto the low resistance region of the structure X1. The state shown in FIG. 3 is a state in which the cleaning material 5 is irradiated onto the highly resistant region of the structure X1.

During the cleaning period, the cleaning material 5 acts as an external force, and the following problem A may occur in the structure X1. The problem A is, for example, a problem in which the structure X1 collapses. Furthermore, the problem A is, for example, a problem in which the structure X1 is damaged.

FIG. 4 is a cross-sectional view showing a cleaning state of the semiconductor cleaning apparatus 100 according to the first embodiment. In addition, in FIG. 4, the support stand 20, the stand rotation shaft 24, the control part 41, and the drive part 42 are not shown in order to make a structure easy to understand. FIG. 5 is an enlarged view of a portion of FIG. 4.

Referring to FIGS. 4 and 5, if the structure X1 does not rotate and the aspect ratio of the structure X1 is large, the structure X1 causes a region R1 that the cleaning material 5 does not reach. There is. In this case, the ability to clean the surface 20a of the semiconductor substrate 11 is reduced.

In the following, the pressure of the cleaning material 5 discharged by the cleaning nozzle 30 will also be referred to as "discharge pressure." The control unit 41 controls the cleaning nozzle 30 to control the discharge pressure. Further, in the following, the standard discharge pressure is also referred to as "discharge pressure P1n" or "P1n". The discharge pressure P1n is a predetermined specified pressure.

In this embodiment, the control unit 41 controls the cleaning nozzle 30 so that the discharge pressure changes depending on the rotation angle of the semiconductor substrate 11. Specifically, the control unit 41 controls the cleaning nozzle 30 so that the relationship between the rotation angle of the semiconductor substrate 11 and the discharge pressure becomes the relationship shown by the characteristic curve L1 in FIG.

FIG. 6 is a graph showing a characteristic curve L1 showing the relationship between the rotation angle of the semiconductor substrate 11 and the discharge pressure in the first embodiment. In FIG. 6, the vertical axis indicates the discharge pressure of the cleaning material 5. The horizontal axis indicates the rotation angle of the semiconductor substrate 11. In the following, the rotation angle of the semiconductor substrate 11 is also simply referred to as a "rotation angle." Note that FIG. 6 shows, as an example, a rotation angle in a range of 45 degrees to 315 degrees. The relationship between the discharge pressure and the rotation angle is such that the characteristic curve L1 shows a sine curve.

When the rotation angle is 180 degrees or 0 degrees, the discharge pressure is the weakest. In the following, the discharge pressure in a situation where the rotation angle is 180 degrees or 0 degrees is also referred to as "discharge pressure P1a" or "P1a." The discharge pressure P1a is smaller than the discharge pressure P1n.

The state where the rotation angle is 180 degrees or 0 degrees is the state shown in FIG. That is, a state in which the rotation angle is 180 degrees or 0 degrees is a state in which the cleaning direction and the longitudinal direction of the structure X1 are perpendicular to each other during the cleaning period.

If the cleaning material 5 is irradiated onto the structure X1 such that the longitudinal direction of the structure X1 having a large aspect ratio is perpendicular to the cleaning direction, the above-mentioned defect A may occur in the structure X1.

In addition, in this embodiment, as shown in the characteristic curve L1 of FIG. 6, when the rotation angle is 180 degrees, the discharge pressure is the weakest. That is, the discharge pressure is the weakest when the cleaning material 5 is irradiated onto the structure X1 so that the longitudinal direction of the structure X1 is orthogonal to the cleaning direction. Thereby, it is possible to suppress the above-mentioned problem A from occurring in the structure X1.

On the other hand, as shown in the characteristic curve L1, when the rotation angle is 90 degrees or 270 degrees, the discharge pressure is the strongest. In the following, the discharge pressure in a situation where the rotation angle is 90 degrees or 270 degrees is also referred to as "discharge pressure P1b" or "P1b." The discharge pressure P1b is greater than the discharge pressure P1n. Note that the discharge pressure P1n corresponds to, for example, the average value of the discharge pressures P1a and P1b.

The state where the rotation angle is 90 degrees or 270 degrees is the state shown in FIG. That is, when the rotation angle is 90 degrees or 270 degrees, the cleaning direction is parallel to the longitudinal direction of the structure X1 during the cleaning period. In other words, the discharge pressure is strongest when the cleaning material 5 is irradiated onto the structure X1 so that the longitudinal direction of the structure X1 is parallel to the cleaning direction.

Note that the state shown in FIG. 3 is a state in which the cleaning material 5 is irradiated onto the structure X1 so that the longitudinal direction of the structure X1 is parallel to the cleaning direction. By irradiating the cleaning material 5 onto the structure X1 so that the longitudinal direction of the structure X1 with a large aspect ratio is parallel to the cleaning direction, the above-mentioned problems can be prevented in the structure X1 even when the discharge pressure is strong. It is possible to suppress the occurrence of A.

As described above, the relationship between the discharge pressure and the rotation angle is such that the characteristic curve L1 shows a sine curve. This indicates that the rotation of the semiconductor substrate 11 and the discharge pressure of the cleaning material 5 are synchronized.

Next, a semiconductor cleaning method performed by the semiconductor cleaning apparatus 100 will be described. The semiconductor cleaning method is a method for cleaning the semiconductor substrate 11. The semiconductor cleaning method includes the following cleaning control process.

The cleaning control process is a cleaning control process in which the semiconductor cleaning apparatus 100 performs a cleaning process. Although details will be described later, in the cleaning control process, the semiconductor cleaning apparatus 100 controls the discharge pressure according to the rotation of the support base 20. That is, the semiconductor cleaning apparatus 100 controls the amount of cleaning material 5 irradiated onto the surface S1a of the semiconductor substrate 11 per unit time in accordance with the rotation of the support base 20. That is, the semiconductor cleaning apparatus 100 changes the amount of cleaning material 5 irradiated onto the surface S1a of the semiconductor substrate 11 per unit time in accordance with the rotation of the support base 20. The unit time is, for example, the time required for the semiconductor substrate 11 to rotate once. The unit time is, for example, a time within a range of 0.1 seconds to 10 seconds.

Further, the cleaning control process is a process performed during the cleaning period. Note that during the cleaning period, the support stand 20 rotates while supporting the semiconductor substrate 11. Therefore, the structure X1 rotates as the support base 20 rotates. In the following, a state in which the cleaning direction intersects with the longitudinal direction of the structure X1 in plan view will also be referred to as a "crossing state". The crossing state is, for example, the state shown in FIG. As the structure X1 rotates, a crossing state occurs.

Specifically, in the cleaning control process, the control unit 41 of the semiconductor cleaning apparatus 100 performs the process Pra or the process Prb depending on the area to be cleaned of the structure X1. The area to be cleaned of the structure X1 changes as the rotation angle of the semiconductor substrate 11 changes. That is, the control unit 41 performs the process Pra or the process Prb depending on the rotation angle of the semiconductor substrate 11.

The process Pra is a process to make the discharge pressure lower than the specified pressure (P1n). The process Prb is a process for making the discharge pressure higher than the specified pressure (P1n). In the cleaning control process, the control unit 41 controls the cleaning nozzle 30 so that the relationship between the rotation angle of the semiconductor substrate 11 and the discharge pressure is the relationship shown by the characteristic curve L1 in FIG. That is, the rotation angle of the semiconductor substrate 11 and the discharge pressure are synchronized.

In the following, the angle between the cleaning direction and the longitudinal direction of the structure X1 in plan view (xy plane) is also referred to as a "cleaning angle." Note that the cleaning angle in FIG. 2 is 90 degrees.

As the area to be cleaned of the structure X1 approaches the low-resistance area shown in FIG. P1n) A process Pra is performed to make it smaller than P1n). That is, the control unit 41 of the semiconductor cleaning apparatus 100 controls the discharge pressure so that the closer the cleaning angle is to 90 degrees, the lower the discharge pressure is. Note that the discharge pressure in a state where the region to be cleaned is a low resistance region shown in FIG. 2 (that is, a state in which the cleaning angle is 90 degrees) is discharge pressure P1a.

Further, as the area to be cleaned of the structure X1 approaches the high resistance area shown in FIG. 3 due to the rotation of the structure A process Prb is performed to make the pressure higher than the pressure (P1n). Note that the discharge pressure in a state where the region to be cleaned is a high resistance region shown in FIG. 3 (that is, a state in which the cleaning direction and the longitudinal direction of the structure X1 are parallel) is the discharge pressure P1b. As described above, the cleaning control process is performed.

Next, as an example, a configuration (hereinafter also referred to as "configuration A1") in which the structure formed on the surface S1a of the semiconductor substrate 11 is a component included in the transistor 60 (for example, a gate electrode 61 to be described later) I will explain about it. FIG. 7 is a cross-sectional view of the transistor 60 in configuration A1.

Transistor 60 includes a gate electrode 61, a source electrode 62, and a drain electrode 63. Gate electrode 61 is arranged between source electrode 62 and drain electrode 63. The gate electrode 61 is, for example, a T-shaped gate electrode. A region R6 is formed under the T-shaped gate electrode 61. The T-shaped gate electrode 61 has a gate structure for shortening the gate length and reducing capacitance. The gate structure is a structure commonly used, particularly in devices used in a high frequency region. Therefore, the above-mentioned region R6 is a region that inevitably occurs. Further, the region R6 is a region where cleaning is difficult due to the structure of the T-shaped gate electrode 61.

FIG. 8 is a cross-sectional view showing a state in which the cleaning material 5 is irradiated onto the transistor 60 in configuration A1. The gate electrode 61 having a T-shaped gate structure has a high aspect ratio. Therefore, the center of gravity of the T-shaped gate electrode 61 is biased toward the top of the gate electrode 61 . Here, it is assumed that the cleaning control process described above is not performed and the cleaning material 5 is irradiated onto the gate electrode 61 from the side of the gate electrode 61. In this case, a problem arises in that the gate electrode 61 collapses due to the discharge pressure of the cleaning material 5 (see FIG. 8).

Further, it is assumed here that the semiconductor substrate 11 does not rotate during the cleaning period. In the following, a situation in which the semiconductor substrate 11 does not rotate during the cleaning period will also be referred to as a "non-rotation situation." In the non-rotating situation, the source electrode 62 or the drain electrode 63 creates a region R7 which is not reached by the cleaning material 5. That is, there is a region where the cleaning material 5 is not irradiated.

Next, another configuration (hereinafter also referred to as "configuration A2") in which the structure formed on the surface S1a of the semiconductor substrate 11 is a component included in the transistor 60 will be described. FIG. 9 is a cross-sectional view of the transistor 60 in configuration A2. Configuration A2 in FIG. 9 differs from configuration A1 in FIG. 7 in that it further includes thick film electrodes 81 and 82. The other configurations of configuration A2 are similar to configuration A1, so detailed description will not be repeated.

In configuration A2, a thick film electrode 81 is formed on the drain electrode 63. Further, a membrane electrode 82 is formed on the source electrode 62. Each of the thick film electrodes 81 and 82 is made of, for example, plating.

FIG. 10 is a cross-sectional view showing a state in which the cleaning material 5 is irradiated onto the transistor 60 of configuration A2. As described above, as shown in FIG. 8, in configuration A1, when the cleaning control process described above is not performed and the cleaning material 5 is irradiated onto the gate electrode 61 from the side of the gate electrode 61, the gate electrode 61 falls down.

Furthermore, in the configuration A2 of FIG. 10, in a non-rotating situation, there are parts and regions that are not irradiated with the cleaning material 5, for example due to the thick film electrode 81. In the following, a member to which the cleaning material 5 is not irradiated is also referred to as a "non-irradiated member." Further, in the following, the area to which the cleaning material 5 is not irradiated is also referred to as a "non-irradiation area".

The non-irradiation member is, for example, the gate electrode 61. Further, the non-irradiation area is, for example, area R6. Further, the non-irradiated region is, for example, a region between the source electrode 62 and the drain electrode 63. As a result, if the above-mentioned cleaning control process is not performed, a problem arises in that, for example, the foreign matter 9 existing in the region R6 cannot be removed. The foreign matter 9 is, for example, dust.

The semiconductor cleaning apparatus 100 of this embodiment performs the cleaning control process described above. In the cleaning control process, the control unit 41 controls the cleaning nozzle 30 so that the relationship between the rotation angle of the semiconductor substrate 11 and the discharge pressure is the relationship shown by the characteristic curve L1 in FIG.

Therefore, for example, in a situation where the cleaning material 5 is irradiated onto the gate electrode 61 from the side of the gate electrode 61 as shown in FIG. 8, the control unit 41 controls the cleaning nozzle 30 so that the discharge pressure is weakened. do. Thereby, damage to the gate electrode 61 as a structure can be reduced.

Further, in this embodiment, the above-mentioned cleaning control process is performed. That is, as shown in FIGS. 1 and 6, the cleaning process is performed while the semiconductor substrate 11 is rotating. Therefore, the cleaning material 5 can be irradiated onto the region R1 in FIG. 5, the region R6 in FIG. 7, the region R7 in FIG. 8, the foreign matter 9 in FIG. 10, and the like.

As described above, according to the present embodiment, the semiconductor cleaning apparatus 100 includes the support table 20 that rotates while supporting the semiconductor substrate 11 and the cleaning nozzle 30. The cleaning nozzle 30 discharges a cleaning material 5 toward the surface S1a of the semiconductor substrate 11 for cleaning the surface S1a. The semiconductor cleaning apparatus 100 controls the amount of cleaning material 5 irradiated onto the surface S1a of the semiconductor substrate 11 per unit time. Thereby, the amount of cleaning material 5 irradiated onto the surface S1a of the semiconductor substrate 11 per unit time can be changed.

Further, according to the present embodiment, the control unit 41 of the semiconductor cleaning apparatus 100 performs the process Pra or the process Prb depending on the area to be cleaned of the structure X1. The process Pra is a process to make the discharge pressure lower than the specified pressure (P1n). The process Prb is a process for making the discharge pressure higher than the specified pressure (P1n).

Specifically, when the area to be cleaned of the structure X1 is a low resistance area, the control unit 41 of the semiconductor cleaning apparatus 100 makes the discharge pressure lower than the specified pressure (P1n). Further, when the area to be cleaned of the structure X1 is a high resistance area, the control unit 41 of the semiconductor cleaning apparatus 100 makes the discharge pressure higher than the specified pressure (P1n). Thereby, the surface S1a of the semiconductor substrate 11 can be efficiently cleaned while suppressing damage to the structure X1.

Further, according to the present embodiment, the discharge pressure is controlled so that the closer the cleaning angle between the cleaning direction and the longitudinal direction of the structure X1 is to 90 degrees in plan view, the lower the discharge pressure is. Thereby, damage to the structure X1 having a high aspect ratio can be reduced.

Further, according to the present embodiment, the cleaning material 5 is irradiated onto the surface S1a of the semiconductor substrate 11 while the semiconductor substrate 11 is rotating. Therefore, the cleaning material 5 can be irradiated onto the structure X1, foreign matter 9, etc. of the semiconductor substrate 11 from various directions. Therefore, areas that are difficult to clean in non-rotating conditions can also be cleaned. As a result, cleaning ability can be improved.

Further, according to this embodiment, the cleaning material 5 used for cleaning is dry ice. Therefore, for example, it is not necessary to perform a drying process after wet processing using water or the like is performed. Furthermore, since the sublimation phenomenon of dry ice is utilized during cleaning, higher cleaning performance can be obtained compared to other cleaning methods. Furthermore, the particle shape of dry ice can be set arbitrarily. Therefore, depending on the object to be cleaned, cleaning can be performed with consideration given to damage.

Note that in the cleaning process, it is required to efficiently remove foreign substances, impurities, etc. without damaging structures on the surface of the semiconductor substrate. Note that the cleaning step may be performed in a situation where the structure on the surface of the semiconductor substrate has a high aspect ratio. In this case, the conventional configuration has a problem in that the cleaning process may damage structures on the surface of the semiconductor substrate. Furthermore, due to the miniaturization and complexity of structures on semiconductor substrates, there is a problem in that areas are created that are difficult to clean.

Therefore, the semiconductor cleaning apparatus 100 of this embodiment has a configuration to achieve the above effects. Therefore, the semiconductor cleaning apparatus 100 of this embodiment can solve each of the above problems. That is, according to the semiconductor cleaning apparatus 100 of this embodiment, even in a situation where a structure with a high aspect ratio is formed on the surface of a semiconductor substrate, foreign matter, impurities, etc. can be removed without damaging the structure. can be removed efficiently. In addition, cleaning can be performed even in areas that are difficult to clean.

<Modification 1>
The configuration of this modification is applied to the first embodiment. FIG. 11 is a diagram showing a semiconductor cleaning apparatus 100 having the configuration of Modification Example 1.

In this modification, a slit member 70 is used. The slit member 70 is a member for adjusting the amount of cleaning material 5 that reaches the surface S1a of the semiconductor substrate 11. The slit member 70 serves as a mask. The shape of the slit member 70 is, for example, a plate shape. The slit member 70 is provided with a plurality of slits SL1 as holes. Each slit SL1 is a hole through which a part of the cleaning material 5 can pass.

FIG. 11 shows a state in which a part of the cleaning material 5 passes through the slit SL1 of the slit member 70 and reaches the surface S1a during the cleaning period.

Note that the number and size of the slits SL1 (holes) provided in the slit member 70 are set arbitrarily.

Note that in the above-described cleaning control process to which this modification is applied, the discharge pressure of the cleaning nozzle 30 is maintained constant (fixed value). That is, in the cleaning control process to which this modification is applied, the discharge pressure of the cleaning nozzle 30 does not change. Therefore, in the cleaning control process to which this modification is applied, the above-mentioned processes Pra and Prb are not performed.

The slit member 70 is arranged between the cleaning nozzle 30 and the surface S1a of the semiconductor substrate 11 supported by the support base 20 in the vertical direction.

Further, the slit member 70 is configured to be rotatable. Note that the slit member 70 rotates so that the rotation axis C1 in FIG. 11 becomes the rotation axis of the slit member 70. The slit member 70 is configured to rotate in synchronization with the rotation of the semiconductor substrate 11 (support stand 20). The slit member 70 is configured to rotate, for example, by being driven by a motor (not shown).

Therefore, in the cleaning control process to which this modification is applied, the slit member 70 rotates as the semiconductor substrate 11 (support stand 20) rotates. Note that in the cleaning control process to which this modification is applied, the control unit 41 of the semiconductor cleaning apparatus 100 controls the drive unit 42 and the motor for rotating the slit member 70 to 20) and the slit member 70 are rotated.

In the following, the period during which the cleaning material 5 reaches the surface S1a via the slit SL1 of the slit member 70 during the cleaning period will also be referred to as a "period Ta." Moreover, in the following, the period during which the cleaning material 5 directly reaches the surface S1a is also referred to as "period Tb". The period Tb is a period during which the cleaning material 5 does not hit the slit member 70.

The amount of cleaning material 5 per unit time that is irradiated onto the surface S1a during the period Ta is smaller than the amount of cleaning material 5 per unit time that is irradiated onto the surface S1a during the period Tb. In the cleaning control process to which this modification is applied, the period Ta and the period Tb repeatedly occur as the slit member 70 rotates.

As a result, in the cleaning control process to which this modification is applied, the semiconductor cleaning apparatus 100 can control the amount of cleaning material 5 irradiated onto the surface S1a of the semiconductor substrate 11 per unit time by rotating the support base 20 and the slit member 70. control. That is, the semiconductor cleaning apparatus 100 controls the amount of cleaning material 5 irradiated onto the surface S1a of the semiconductor substrate 11 per unit time according to the rotation of the support base 20 and the slit member 70. Therefore, even when the discharge pressure of the cleaning nozzle 30 is maintained constant (fixed value), the amount reaching the surface S1a of the semiconductor substrate 11 can be controlled.

Here, an example of the arrangement of the slit member 70 will be described. In the following, the area of the surface S1a of the semiconductor substrate 11 in FIG. 2 that is irradiated with the cleaning material 5 will also be referred to as the "irradiation area." The irradiation area in FIG. 2 is an area where the longitudinal direction of the structure X1 and the cleaning direction are orthogonal.

Furthermore, hereinafter, the pressure of the cleaning material 5 irradiated onto the irradiation area in FIG. 2 will also be referred to as "irradiation pressure." The slit member 70 rotates such that, for example, a curve representing the relationship between the rotation angle of the semiconductor substrate 11 and the irradiation pressure becomes a characteristic curve L1 in FIG. 6 .

The slit member 70 is arranged, for example, so as to cover the irradiation area in FIG. 2 . Specifically, the slit member 70 is configured so that the slit member 70 rotates in synchronization with the rotation of the semiconductor substrate 11 (support base 20) so as to always cover the irradiation area shown in FIG. Ru.

Thereby, the irradiation pressure of the cleaning material 5 in the irradiation region shown in FIG. 2 can be weakened. Therefore, even in a state where the longitudinal direction of the structure X1 and the cleaning direction are perpendicular to each other, it is possible to suppress the above-mentioned problem A from occurring in the structure X1.

As explained above, according to this modification, the number and size of the slits SL1 (holes) provided in the slit member 70 are arbitrarily set. Thereby, in a situation where the discharge pressure of the cleaning nozzle 30 is constant, the amount of irradiation of the cleaning material 5 during the period Ta can be adjusted. Thereby, damage to the object to be cleaned can be reduced. Further, by rotating the slit member 70, cleaning can be performed in accordance with the object to be cleaned.

<Modification 2>
The configuration of this modification is applied to all or part of Embodiment 1 and Modification 1. FIG. 12 is a diagram showing a semiconductor cleaning apparatus 100 having the configuration of Modification 2. In FIG. Note that FIG. 12 shows, as an example, a configuration in which the configuration of Modified Example 2 is applied to the configuration of FIG. Moreover, in order to mainly explain the configuration of this modification, FIG. 12 does not show the control section 41 and the drive section 42.

In this modification, a container 90 is used. The container 90 has a box shape with a bottom and no lid. That is, the top of the container 90 is open. In this modification, a container 90 is provided below the support stand 20. Note that the size of the container 90 in a plan view is larger than the size of the support base 20 in a plan view.

Here, it is assumed that foreign matter 9 is attached to the surface S1a of the semiconductor substrate 11. The foreign matter 9 is, for example, dust. In this case, by performing a cleaning process in which the cleaning nozzle 30 discharges the cleaning material 5, the foreign matter 9 is accommodated in the container 90 through the path Pt1, for example.

Note that the container 90 may have a suction mechanism. The suction mechanism has a function of attracting foreign matter such as dust into the container 90. In this case, the foreign matter 9 removed from the surface S1a is sucked into the container 90 by the suction mechanism of the container 90, for example, through the path Pt1.

As explained above, according to this modification, the container 90 is provided below the support stand 20. Note that the container 90 may have a suction mechanism. Thereby, the foreign matter 9 removed from the surface S1a of the semiconductor substrate 11 can be contained in the container 90.

Further, it is possible to suppress the following problem B from occurring due to the foreign matter 9 removed from the surface S1a of the semiconductor substrate 11. Problem B is, for example, a problem in which the foreign matter 9 removed from the surface S1a of the semiconductor substrate 11 adheres to the semiconductor substrate 11 again. Further, defect B is, for example, a defect in which foreign matter 9 adheres to an area where the semiconductor cleaning apparatus 100 would malfunction, causing the semiconductor cleaning apparatus 100 to malfunction.

Note that within the scope of the present invention, the embodiments and each modification can be freely combined, and the embodiments and each modification can be modified or omitted as appropriate.

For example, elements other than the rotation angle may be used to control the discharge pressure. In order to control the discharge pressure, for example, a configuration (hereinafter referred to as "modified configuration A") using a mark and a camera having a function of detecting the mark may be used.

In variant configuration A, for example, the camera is fixed to the cleaning nozzle 30. In the modified configuration A, for example, a mark is provided at the end of the surface S1a of the semiconductor substrate 11, and the mark is detected by a camera. Further, when the camera detects a mark, the camera notifies the control unit 41 that the mark has been detected.

In variant configuration A, the mark is provided at the edge of the surface S1a so that the camera detects the mark, for example in the state of FIG. 2. In modified configuration A, when the camera detects a mark on the surface S1a during the cleaning period when the support base 20 (semiconductor substrate 11) is rotating, the control unit 41 controls the cleaning nozzle 30 to specify the discharge pressure. Make it smaller than the pressure (P1n).

5 cleaning material, 11 semiconductor substrate, 20 support stand, 30 cleaning nozzle, 41 control unit, 42 drive unit, 70 slit member, 90 container, 100 semiconductor cleaning equipment, X1 structure.

Claims (11)

A semiconductor cleaning apparatus for cleaning a semiconductor substrate having a surface as a surface to be cleaned,
a support stand that rotates while supporting the semiconductor substrate;
Equipped with a cleaning nozzle,
The cleaning nozzle discharges a cleaning material toward the surface of the semiconductor substrate for cleaning the surface,
The semiconductor cleaning device controls a discharge pressure, which is a pressure of the cleaning material discharged from the cleaning nozzle , according to a rotation angle of the semiconductor substrate .
Semiconductor cleaning equipment. A semiconductor cleaning apparatus for cleaning a semiconductor substrate having a surface as a surface to be cleaned,
a support stand that rotates while supporting the semiconductor substrate;
Equipped with a cleaning nozzle,
The cleaning nozzle discharges a cleaning material toward the surface of the semiconductor substrate for cleaning the surface,
The surface of the semiconductor substrate is provided with a mark that can be detected by a camera fixed to the cleaning nozzle,
The semiconductor cleaning device controls a discharge pressure that is a pressure of the cleaning material discharged from the cleaning nozzle when the camera detects the mark during a period when the semiconductor substrate is rotating.
Semiconductor cleaning equipment. A semiconductor cleaning apparatus for cleaning a semiconductor substrate having a surface as a surface to be cleaned,
a support stand that rotates while supporting the semiconductor substrate;
Equipped with a cleaning nozzle,
The cleaning nozzle discharges a cleaning material toward the surface of the semiconductor substrate for cleaning the surface,
The semiconductor cleaning device controls the amount of the cleaning material irradiated onto the surface of the semiconductor substrate per unit time according to rotation of the support base,
The semiconductor cleaning device controls the discharge pressure, which is the pressure of the cleaning material discharged from the cleaning nozzle, in accordance with the rotation of the support base,
A structure is formed on the surface of the semiconductor substrate,
The structure rotates as the support base rotates,
The semiconductor cleaning apparatus performs a process of reducing the discharge pressure below a specified pressure, or increasing the discharge pressure above the specified pressure, depending on a region of the structure that is to be irradiated with the cleaning material. carry out processing,
Semiconductor cleaning equipment. The shape of the structure is elongated,
As the structure rotates, a state occurs in which the cleaning direction, which is the direction in which the cleaning material faces the structure, intersects the longitudinal direction of the structure in plan view,
The semiconductor cleaning device controls the discharge pressure such that the closer the angle between the cleaning direction and the longitudinal direction of the structure is to 90 degrees in plan view, the lower the discharge pressure is.
The semiconductor cleaning apparatus according to claim 3. A semiconductor cleaning apparatus for cleaning a semiconductor substrate having a surface as a surface to be cleaned,
a support stand that rotates while supporting the semiconductor substrate;
Equipped with a cleaning nozzle,
The cleaning nozzle discharges a cleaning material toward the surface of the semiconductor substrate for cleaning the surface,
The semiconductor cleaning device controls the amount of the cleaning material irradiated onto the surface of the semiconductor substrate per unit time according to rotation of the support base,
A slit member is disposed between the cleaning nozzle and the surface of the semiconductor substrate supported by the support base,
The slit member is provided with a slit,
Semiconductor cleaning equipment. A container is provided below the support base,
the top of the container is open;
A semiconductor cleaning apparatus according to any one of claims 1 to 5. the cleaning material is dry ice;
A semiconductor cleaning apparatus according to any one of claims 1 to 6. A semiconductor cleaning method performed by a semiconductor cleaning device that cleans a semiconductor substrate having a surface as a surface to be cleaned, the method comprising:
The semiconductor cleaning equipment includes:
a support stand that rotates while supporting the semiconductor substrate;
a cleaning nozzle that discharges a cleaning material for cleaning the surface toward the surface of the semiconductor substrate,
The semiconductor cleaning method includes:
(a) The semiconductor cleaning apparatus includes a step of controlling the discharge pressure, which is the pressure of the cleaning material discharged from the cleaning nozzle, according to the rotation angle of the semiconductor substrate .
Semiconductor cleaning method. A semiconductor cleaning method performed by a semiconductor cleaning device that cleans a semiconductor substrate having a surface as a surface to be cleaned, the method comprising:
The semiconductor cleaning equipment includes:
a support stand that rotates while supporting the semiconductor substrate;
a cleaning nozzle that discharges a cleaning material for cleaning the surface toward the surface of the semiconductor substrate,
The surface of the semiconductor substrate is provided with a mark that can be detected by a camera fixed to the cleaning nozzle,
The semiconductor cleaning method includes:
(a) The semiconductor cleaning apparatus controls the discharge pressure, which is the pressure of the cleaning material discharged from the cleaning nozzle, when the camera detects the mark during a period when the semiconductor substrate is rotating. prepare,
Semiconductor cleaning method. A semiconductor cleaning method performed by a semiconductor cleaning device that cleans a semiconductor substrate having a surface as a surface to be cleaned, the method comprising:
The semiconductor cleaning equipment includes:
a support stand that rotates while supporting the semiconductor substrate;
a cleaning nozzle that discharges a cleaning material for cleaning the surface toward the surface of the semiconductor substrate,
The semiconductor cleaning method includes:
(a) comprising the step of controlling the amount of the cleaning material irradiated onto the surface of the semiconductor substrate per unit time according to the rotation of the support base;
A slit member is disposed between the cleaning nozzle and the surface of the semiconductor substrate supported by the support base,
The slit member is provided with a slit,
In the step (a), the slit member rotates;
Semiconductor cleaning method. the cleaning material is dry ice;
The semiconductor cleaning method according to any one of claims 8 to 10.

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