JP4364744B2 - Etching apparatus and etching method - Google Patents

Description

  The present invention relates to an etching apparatus and an etching method for etching a peripheral portion of a disk-shaped substrate.

  For example, when a circuit pattern is formed on a semiconductor wafer as a substrate, there is a step of forming a laminated film composed of a plurality of thin films such as a conductive film and an insulating film on the semiconductor wafer. Film formation on the semiconductor wafer is performed by, for example, a CVD apparatus. When a laminated film is formed on a semiconductor wafer, the laminated film may also be formed on the periphery of the semiconductor wafer. FIG. 5A is a cross-sectional view in which a laminated film M composed of a plurality of thin films is formed on the peripheral edge of the semiconductor wafer W.

  The semiconductor wafer W on which the laminated film M is formed is cleaned by a spin processing apparatus or the like. In that case, if the peripheral portion of the semiconductor wafer W is clamped by the spin processing device, the laminated film M at the peripheral portion may be peeled off, and the peeled laminated film M adheres to the semiconductor wafer W or another semiconductor wafer, Causes contamination.

  Therefore, conventionally, when the laminated film M is formed on the semiconductor wafer W, the peripheral portion is etched over several mm, for example, about 5 mm as shown by d in FIG. The removal of the film M is performed. As a method of etching the peripheral portion of the semiconductor wafer W, an etching solution is sprayed onto the peripheral portion of the semiconductor wafer W by a nozzle.

  According to the method of performing etching by spraying the etching liquid onto the peripheral edge of the semiconductor wafer with a nozzle, the etching liquid sprayed on the peripheral edge is scattered on the device surface of the semiconductor wafer, and unnecessary etching is performed on the device surface. There is a fear.

  In addition, when the etching liquid is sprayed to the peripheral edge of the semiconductor wafer by the nozzle, the peripheral edge of the semiconductor wafer is held by the spin processing device and the semiconductor wafer is rotated. However, when etching is performed while holding and rotating the peripheral edge portion of the semiconductor wafer in a spin processing apparatus, the holding portion may not be reliably etched.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate etching apparatus and etching method capable of reliably etching the peripheral edge of a semiconductor wafer and preventing unnecessary etching on the device surface.

This invention is an etching apparatus for etching a disk-shaped substrate with an etching solution,
Holding driving means for holding the substrate so that the device surface is inclined downward in the inclination direction and rotationally driving in the circumferential direction;
Provided at a position corresponding to the lower end portion of the substrate held by the holding drive means, the liquid receiving portion to which the etching solution is supplied and the peripheral portion of the device surface of the substrate facing the outer peripheral surface of the substrate and the liquid An etching apparatus comprising: a control member having a liquid introducing portion that guides the etching solution supplied to the receiving portion to the peripheral portion of the device surface of the substrate by surface tension.

  It is preferable that the control member is provided so that the length of the liquid introduction portion facing the radial direction of the peripheral portion of the device surface of the substrate can be adjusted.

Etch solution supply means for supplying an etchant toward the central portion is provided at a position corresponding to the central portion in the radial direction of the non-device surface opposite to the device surface of the substrate,
Etching supplied to the non-device surface by the etching solution supply means by injecting gas along the radial direction of the portion of the non-device surface corresponding to the downstream side in the rotation direction of the substrate with respect to the control member. It is preferable that a first air knife is provided that prevents the liquid from being brought into the downstream side in the rotation direction of the substrate together with the rotating substrate and guides the liquid to the liquid receiving portion of the control member. .

  It is preferable that a rinsing liquid supply means for supplying a rinsing liquid toward the central portion is provided at a position corresponding to the central portion in the radial direction of the non-device surface of the substrate.

  The portion of the device surface of the substrate that is downstream of the control member in the rotational direction of the substrate is jetted of gas to that portion, and the liquid introduction portion of the device is opposed to the liquid introduction portion of the control member. It is preferable that a second air knife for preventing the etching liquid guided to the peripheral edge from rising radially inward from the peripheral edge of the substrate is provided.

Discs are arranged on the device surface of the substrate to face each other at a predetermined interval,
It is preferable that a gas nozzle for supplying gas between the device surface and the disk is provided at the center of the disk.

This invention is an etching method for etching a disk-shaped substrate with an etching solution,
A step of tilting and holding the substrate so that the device surface is on the lower side of the tilt direction, and rotationally driving in the circumferential direction;
Supplying an etchant to the outer peripheral surface of the lower end of the substrate;
And etching the peripheral portion of the device surface with the etching solution supplied to the outer peripheral surface of the lower end portion of the substrate, and etching the peripheral portion.

  It is preferable to provide a step of jetting gas to the peripheral portion of the device surface of the substrate and preventing the etching liquid guided to the peripheral portion from rising inward in the radial direction.

  According to the present invention, since the etching solution can be guided to the peripheral edge of the substrate, only the peripheral edge can be reliably etched.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic configuration diagram of an etching apparatus according to an embodiment of the present invention. This etching apparatus includes a holding drive mechanism 1 for holding a semiconductor wafer W as a disk-shaped substrate and rotating it in the circumferential direction. The holding drive mechanism 1 has a base plate 2. A pair of support columns 3 are erected on the upper surface of the base plate 2 at a predetermined interval.

  As shown in FIG. 2, a prismatic mounting member 4 is provided at the upper end of the pair of support columns 3 with the lower end surface fixed. One side surface of the attachment member 4 is formed on an inclined surface 5 inclined at a predetermined angle. The inclination angle of the inclined surface 5 with respect to the horizontal plane is preferably 75 degrees or less, and is set to 75 degrees in this embodiment.

  A rectangular installation plate 6 is provided on the inclined surface 5 with one side being fixed in contact. That is, the installation plate 6 is inclined at an angle of 75. A pair of roller mounting plates 11 are movably provided along the width direction on the other side surface of the installation plate 6, that is, on both end portions in the width direction of the upper surface in the tilt direction. That is, a pair of guide rails 12 spaced apart at a predetermined interval in the height direction are provided horizontally along the width direction at both ends in the width direction on the upper surface of the installation plate 6.

  As shown in FIG. 2, a pair of receiving members 13 that are slidably engaged with the guide rails are provided on the back surface of the roller mounting plate 11. Thereby, the pair of roller mounting plates 11 can be moved along the width direction of the installation plate 6.

  A drive roller 14 is rotatably provided at one end and the other end of each roller mounting plate 11. As shown in FIG. 2, a V-shaped holding groove 14 a is formed on the outer peripheral surface of the driving roller 14. At least one of the four drive rollers 14 is rotationally driven by a drive motor 15 as a drive source provided on the back surface of the roller mounting plate 11.

  As shown in FIG. 1, a pair of roller attachment plates 11 is connected to a rod 17 of a cylinder 16 attached to the movable body 4 with the axis line being substantially horizontal. By driving the rod 17, the pair of roller mounting plates 11 moves along the guide rail 12. That is, the pair of roller mounting plates 11 is driven in the direction of contacting and separating.

  Accordingly, when the pair of roller mounting plates 11 are driven in the approaching direction from the separated state, the V-shaped holding grooves 14a (shown in FIG. 2) formed on the outer peripheral surfaces of the four driving rollers 14 are used to form the semiconductor wafer W. The outer periphery can be held.

In other words, the semiconductor wafer W can be held by the four drive rollers 14 at an inclination angle of 75 degrees, which is the same inclination angle as the installation plate 6. At this time, the semiconductor wafer W is the device surface d ₁ on which a circuit pattern is formed is a lower side of the inclined direction, is held toward the mounting plate 6 side.

  After the semiconductor wafer W is held by the drive roller 14, the drive motor 15 is operated to rotate one of the four drive rollers 14 in the clockwise direction indicated by the arrow in FIG. Can be rotated counterclockwise as indicated by an arrow.

As shown in FIGS. 1 and 3, the upper surface of the semiconductor wafer W held inclined at a predetermined angle, that is, the radial center portion of the non-device surface d ₂ opposite to the device surface d ₁ , an etching nozzle 21 for supplying etching liquid to the non-device surface d _2, and the rinse nozzle 22 for supplying a rinsing liquid to wash away the etching liquid is disposed.

Liquids such as an etching solution and a rinsing solution supplied to the non-device surface d ₂ of the semiconductor wafer W rotating from the nozzles 21 and 22 flow downward in the radial direction of the semiconductor wafer W. The liquid that has flowed downward in the radial direction of the semiconductor wafer W, together with the semiconductor wafer W rotated by the pressure of the gas sprayed in a curtain form from the first air knife 23 arranged along the radial direction, is this semiconductor wafer W. Is prevented from being brought downstream in the rotation direction.

Thereby, the etching solution or the rinsing solution supplied from the nozzles 21 and 22 to the central portion of the non-device surface d ₂ is rotated together with the semiconductor wafer W rotated by the pressure of the gas injected from the first air knife 23. Without flowing in the radial direction as indicated by an arrow X in FIG.

A control member having an L-shaped side surface at a position slightly upstream of the first air knife 23 relative to the rotation direction of the semiconductor wafer W and corresponding to the peripheral edge of the semiconductor wafer W. 24 is provided. The control member 24 has a liquid receiving portion 24a that faces the outer peripheral surface of the semiconductor wafer W as shown in FIG. 3 (b), along the radial direction of the peripheral portion of the device surface d ₁ of the semiconductor wafer W And a liquid introduction section 24b located opposite to each other.

The control member 24 is provided so as to be driven along the radial direction of the semiconductor wafer W by an actuator 26 such as a linear motor. Thereby, the control member 24 is driven between the position indicated by the solid line in FIG. 3B and the position indicated by the chain line, and the liquid introduction portion 24b of the control member 24 indicated by Y in FIG. thereby making it possible to adjust the length opposite to the periphery of the surface d ₁ in millimeters.

As shown in FIG. 3B, the control member 24 is provided with an inclination at the same angle as the inclination angle of the semiconductor wafer W. Thereby, the liquid receiving portion 24a is inclined to become lower toward the device surface d ₁ from the non-device surface d ₂ of the semiconductor wafer W. Further, as shown in FIG. 7, the liquid introduction part 24 b faces the device surface d ₂ almost in parallel with a slight gap 27. In addition, although the upper surface of the liquid receiving part 24a may be a flat surface, it may be a concave curved surface.

The etching solution or the rinsing solution that has flowed along the lower radial direction of the non-device surface d ₂ by the pressure of the gas injected from the first air knife 23 is received by the liquid receiving portion 24 a of the control member 24.

The liquid received by the liquid receiving part 24a flows on the upper surface of the liquid receiving part 24 toward the liquid guiding part 24b. Liquid flows into liquid guiding section 24b, the liquid guiding section 24b is because face each other through the lower peripheral edge and a slight gap 27 of the device surface d _2, increasing the distance 27 by surface tension. FIG. 3B shows a state in which the liquid L such as an etching liquid or a rinsing liquid is rising at the interval 27 due to surface tension.

The lower end portion of the device surface d ₂ of the semiconductor wafer W, downstream in the rotation direction of the semiconductor wafer W than the control member 24, the second air knife 28 is provided as shown in FIG. 4 (b) ing. The second air knife 28 is shorter than the first air knife 23, and the gas injection direction is directed downward in the radial direction, that is, toward the outer peripheral edge of the semiconductor wafer W, and slightly on the upstream side in the rotation direction of the semiconductor wafer W. It is inclined and arranged.

  Thereby, the liquid L supplied to the liquid receiving portion 24a of the control member 24 and rising up the liquid guiding portion 24b has a diameter larger than that of the upper end of the liquid guiding portion 24b due to the pressure of the gas ejected from the second air knife 28. As shown by an arrow Z in FIG. 4B, as the semiconductor wafer W rotates, from one end of the liquid introduction part 24b located on the downstream side in the rotation direction. It will be dripped.

On the device surface d ₂ of the semiconductor wafer W, a disk 31 having a slightly smaller diameter than the semiconductor wafer W is disposed to face the device surface d ₂ with a slight gap. This is the center of the disc 31 the gas nozzle 32 for injecting an inert gas such as nitrogen to the device surface d ₂ are connected. The inert gas injected into the central portion of the gas nozzle 32 device surface d ₂ flows toward the gap between the device surface d ₂ and the disk 31 radially outward. This prevents dirt from adhering to the portion of the device surface d ₂ facing the disk 31.

Next, the operation when the semiconductor wafer W is etched by the etching apparatus having the above configuration will be described.
In a state where the pair of roller mounting plates 11 are driven in a direction away from each other by the cylinder 16, the semiconductor wafer W is supplied between the roller mounting plates 11 by a robot (not shown) so that the device surface d ₂ is directed toward the installation plate 6. . Next, when the pair of roller mounting plates 11 are driven in the approaching direction, the outer peripheral edge of the semiconductor wafer W is held by the pair of driving rollers 14 provided on each roller mounting plate 11. That is, the semiconductor wafer W is held by the driving roller 14 the device surface d ₂ is directed to the inclination direction lower side.

When the semiconductor wafer W is held, the drive motor 15 is operated to rotate the semiconductor wafer W in the counterclockwise direction indicated by an arrow in FIG. At the same time, an etching solution is supplied from the etching nozzle 21 to the central portion of the non-device surface d ₁ of the semiconductor wafer W.

The etching solution supplied to the non-device surface d ₁ of the semiconductor wafer W flows downward in the radial direction of the non-device surface d ₁ inclined at a predetermined angle, and flows from the first air knife 23 to the semiconductor. The pressure of the gas injected along the radial direction of the wafer W prevents the first air knife 23 from flowing upstream of the semiconductor wafer W in the rotational direction.

  That is, the etching solution supplied to the central portion of the semiconductor wafer W is sprayed from the first air knife 23 as shown by the arrow X in FIG. 4A even though the semiconductor wafer W is rotating. Due to the pressure of the gas flowing, the gas flows almost linearly along the outside in the radial direction of the semiconductor wafer W and reaches the liquid receiving portion 24a of the control member 24 arranged at the lower end.

Although the semiconductor wafer W is rotating, the etching solution flows linearly outward from the center of the semiconductor wafer W as indicated by an arrow X in FIG. non-device surface d ₁ of the wafer W will be entirely etched. That is, it is possible to remove the non-device surface d ₁ dirt.

  The etching solution that has reached the liquid receiving portion 24a of the control member 24 rises along the liquid guiding portion 24b by surface tension as shown in FIG. Since the etching liquid that has risen in the liquid guiding part 24b receives the pressure of the gas injected from the second air knife 28, it flows or rotates inward in the radial direction of the semiconductor wafer W from the upper end of the liquid guiding part 24b. The semiconductor wafer W is prevented from flowing upstream from the second air knife 28.

Moreover, the semiconductor wafer W is inclined at an angle of 75 degrees to the device surface d ₂ on the lower side. Therefore, since the etching solution becomes resistance when increasing toward the distal end radially inward of the device surface d ₂ from the liquid guiding section 24b of the control member 24, the etchant control member 24 also by the It is prevented from flowing inward in the radial direction of the semiconductor wafer W, which is above the liquid guiding portion 24b.

Thereby, etching liquid supplied to the liquid receiving portion 24a is made to be etched only part facing the liquid guiding portion 24b of the peripheral portion of the device surface d ₂ of the semiconductor the wafer W, the device surface d ₂ The portion radially inward from the liquid guiding portion 24b is not etched.

The length Y of the liquid introduction part 24 b facing the device surface d ₂ shown in FIG. 3B can be adjusted by the actuator 26. Thereby, the length dimension from the outer peripheral surface radially inwardly of the semiconductor wafer W of the device surface d ₂ is etched by the etching solution, that is possible to precisely set the etching length along the radial direction of the peripheral portion and Become.

On the other hand, a disk 31 is provided on the device surface d _{2 so as} to face each other at a predetermined interval. A gas nozzle 32 is connected to the center of the disk 31, and a gas is supplied from the nozzle 32 to the device surface d _2. Is injected. Gas injected into the device surface d ₂ flows radially outward from the center portion of the device surface d _2.

Therefore, even if scattered consist liquid guiding section 24b of the control member 24 in the pressure of the gas etchant etching the peripheral portion of the device surface d ₂ is injected from the second air knife 28 to the mist-like, its because never mist entering between the device surface d ₂ and the disk 31, it does not pollute the device surface d ₂ attached etchant to the device surface d _2.

Thus, if was etched peripheral portion of the device surface d ₂ of the semiconductor wafer W by the etchant, to stop the supply of the etching liquid from the rinse nozzle 22 to the center portion of the non-device surface d ₁ of the semiconductor wafer W Supply rinse solution.

Rinse liquid supplied to the non-device surface d ₁ flows as with the etching solution. In other words, the entire non-device surface d ₁ of the semiconductor wafer W is rinsed, and along the radial direction of the semiconductor wafer W along the first soot air knife 23 with the pressure of the substrate sprayed from the first air knife 23. The flow is supplied to the liquid receiving portion 24 a of the control member 24.

  Subsequently, the liquid receiving portion 24a is guided to the liquid introducing portion 24b by surface tension. Therefore, the portion of the semiconductor wafer W etched with the etching solution is rinsed with the rinsing solution. That is, since the rinsing liquid flows along the same path as the etching liquid, the portion of the semiconductor wafer W etched by the etching liquid can be reliably rinsed.

If the semiconductor wafer W is rinsed, the supply of the rinse liquid is stopped, and gas is injected from the first air knife 23 and the second air knife 28. Gas ejected from the first air knife 23, a drying treatment of the non-device surface d ₁ whole semiconductor wafer W. Gas ejected from the second air knife 28 to drying the peripheral portion of the device surface d ₂ of the semiconductor wafer W. As a result, the portion of the semiconductor wafer W rinsed with the rinse liquid is dried.

  That is, according to the etching apparatus of the present invention, not only the peripheral portion of the device surface of the semiconductor wafer W is etched, but also the rinsing process and the drying process can be successively performed following the etching process.

The present invention is not limited to the above embodiment. For example, in the above embodiment, in order to etch the non-device surface d ₁ , the etching solution is sprayed from the central portion of the non-device surface d ₁ by the etching nozzle and supplied to the liquid receiving portion 24 a of the control member 24. the non-device surface d ₁ when there is no need to etch, the etchant directly to the liquid receiving portion 24a, may be supplied. In that case, the rinse liquid may be supplied directly to the liquid receiving portion 24a as well.

  Further, the tilt angle of the semiconductor wafer W is not limited to 75 degrees, and the tilt angle of the semiconductor wafer W may be further tilted from 75 degrees in the horizontal direction. If the inclination angle of the semiconductor wafer W is reduced, the liquid that rises in the liquid introduction part 24b due to surface tension is less likely to flow radially inward than the liquid introduction part 24b. It is possible to prevent etching beyond the dimension facing 24b.

BRIEF DESCRIPTION OF THE DRAWINGS The front view which shows schematic structure of the etching apparatus of one embodiment of this invention. Etching shown in FIG. 1 Side view of the present invention. (A) is a side view showing the arrangement relationship of the semiconductor wafer, the first and second air knives and the control member, and (b) is an enlarged view of the lower end portion of the semiconductor wafer provided with the control member. (A) is a figure for demonstrating the flow of the etching liquid supplied from the nozzle for an etching with the gas injected from a 1st air knife, (b) is for control by the gas injected from a 2nd air knife. The figure for demonstrating the flow of the etching liquid which rose to the liquid introduction part of a member. (A) is an expanded sectional view of the edge part of the semiconductor wafer before being etched, (b) The expanded sectional view of the edge part of the semiconductor wafer after being etched.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Holding drive mechanism (holding drive means), 11 ... Roller mounting plate, 14 ... Drive roller, 21 ... Etching nozzle, 22 ... Rinsing nozzle, 23 ... 1st air knife, 24 ... Control member, 24a ... liquid receiver, 24b ... liquid guiding unit, 26 ... actuator, 28 ... second air knife, 31 ... disc, 32 ... gas nozzle, W ... semiconductor wafer (substrate), d 1 _... non-device side, _{d 2} ... Device face.

Claims (8)

An etching apparatus for etching a disk-shaped substrate with an etching solution,
Holding driving means for holding the substrate so that the device surface is inclined downward in the inclination direction and rotationally driving in the circumferential direction;
Provided at a position corresponding to the lower end portion of the substrate held by the holding drive means, the liquid receiving portion to which the etching solution is supplied and the peripheral portion of the device surface of the substrate facing the outer peripheral surface of the substrate and the liquid An etching apparatus comprising: a control member having a liquid guiding portion that guides the etching solution supplied to the receiving portion to the peripheral portion of the device surface of the substrate by surface tension.   The etching apparatus according to claim 1, wherein the control member is provided so that the length of the liquid introduction portion facing the radial direction of the peripheral portion of the device surface of the substrate can be adjusted. Etch solution supply means for supplying an etchant toward the central portion is provided at a position corresponding to the central portion in the radial direction of the non-device surface opposite to the device surface of the substrate,
Etching supplied to the non-device surface by the etching solution supply means by injecting gas along the radial direction of the portion of the non-device surface corresponding to the downstream side in the rotation direction of the substrate with respect to the control member. A first air knife is provided that prevents the liquid from being carried along with the rotating substrate to the downstream side in the rotation direction of the substrate with respect to the control member and guides it to the liquid receiving portion of the control member. The etching apparatus according to claim 1.   4. An etching apparatus according to claim 3, wherein a rinse liquid supply means for supplying a rinse liquid toward the central portion is provided at a position corresponding to the central portion in the radial direction of the non-device surface of the substrate. .   The portion of the device surface of the substrate that is downstream of the control member in the rotational direction of the substrate is jetted of gas to that portion, and the liquid introduction portion of the device is opposed to the liquid introduction portion of the control member. The etching apparatus according to claim 1, further comprising a second air knife for preventing the etching liquid guided to the peripheral edge from rising radially inward from the peripheral edge of the substrate. Discs are arranged on the device surface of the substrate to face each other at a predetermined interval,
2. An etching apparatus according to claim 1, wherein a gas nozzle for supplying a gas is provided between the device surface and the disk at a central portion of the disk. An etching method for etching a disk-shaped substrate with an etching solution,
A step of tilting and holding the substrate so that the device surface is on the lower side of the tilt direction, and rotationally driving in the circumferential direction;
Supplying an etchant to the outer peripheral surface of the lower end of the substrate;
An etching method comprising: a step of guiding an etching solution supplied to an outer peripheral surface of a lower end portion of the substrate to a peripheral portion of the device surface and etching the peripheral portion.   8. The method according to claim 7, further comprising a step of spraying a gas to a peripheral portion of the device surface of the substrate and preventing the etching solution guided to the peripheral portion from rising inward in the radial direction. Etching method.

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