JP2007207811A - Sheet-type etching equipment of wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the local shape collapse of the edge of a wafer by preventing an etching liquid from being routed to the lower surface of the wafer, and preventing the scattered etching liquid from adhering to the upper surface of the wafer again. <P>SOLUTION: While the wafer 11 is placed on a chuck 12 for holding and rotated, the etching liquid 14 is supplied to the upper surface of the wafer for etching the upper surface of the wafer. The chuck is allowed to have a gas jet mechanism 17 for blowing off the etching liquid flowing down while traveling at the edge 11a of the wafer on the chuck to the radial outside of the wafer by jetting out gas. An annular guide piece 18 that is an inclined surface inclined to the radial outside of the chuck as an inner-periphery surface 18a goes upward is allowed to project at the upper part of the outer periphery of the chuck. An inclination angle θ and a height H of the inclination surface of the guide piece are formed in ranges of 10-90° and 0.1-2 mm, respectively. Then, a distance T from the outer periphery of the lower surface of the wafer on the chuck to the inner periphery of the guide piece from a crossing line P at the lower edge of the edge is set in a range of 0.05-5 mm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus for etching an upper surface of a wafer one by one by centrifugal force by supplying an etching solution to the upper surface while rotating the wafer.

In general, the manufacturing process of a semiconductor wafer consists of chamfering, mechanical polishing (lapping), etching, mirror polishing (polishing), and cleaning of a wafer obtained by cutting and slicing from a single crystal ingot. It is produced as a wafer having a degree. A wafer that has undergone a machining process such as block cutting, outer diameter grinding, slicing, or lapping has a damaged layer, that is, a work-affected layer on its upper surface. The work-affected layer must be completely removed because it induces crystal defects such as slip dislocations in the device manufacturing process, lowers the mechanical strength of the wafer, and adversely affects the electrical properties. Etching is performed to remove the work-affected layer. As the etching process, immersion etching or single-wafer etching is performed.
Since the single wafer etching can control the surface roughness and texture size of a large-diameter wafer, it has been studied as an optimum etching method. Single wafer etching is a method in which an etching solution is dropped onto the upper surface of a flattened single wafer, and the etched etching solution is spread over the entire upper surface of the wafer by rotating (spinning) the wafer. The etching solution supplied to the upper surface of the wafer spreads from the supplied location to the entire upper surface of the wafer due to the centrifugal force generated by rotating the wafer and reaches the edge of the wafer, so that the edge of the wafer is etched simultaneously with the upper surface of the wafer. Will be. Most of the supplied etching solution is blown off from the edge portion of the wafer by centrifugal force and collected by a cup or the like provided in the etching apparatus. However, there is a problem that part of the etching solution flows from the edge portion of the wafer to the lower surface of the wafer and also etches the edge portion of the wafer and the lower surface of the wafer.

In order to eliminate this point, the rotation drive unit is connected to the central axis of the rotation base, a positioning unit for placing the wafer at a predetermined position around the rotation base is provided, and a holding member that holds the peripheral surface of the wafer Is disclosed between positioning portions around the rotating base, and a single wafer processing mechanism is disclosed in which a processing nozzle for sending an etching solution is provided above the rotating base (see, for example, Patent Document 1). In this single wafer processing mechanism, when the protrusion height Xmm of the positioning portion and the holding member based on the contact portion with the rotating base on the lower surface of the wafer is Amm, the thickness of the peripheral edge portion of the wafer is 0 <X <(A + 0). .5). A gas supply block is provided around the central axis of the lower portion of the rotary base, and a supply port through which gas from the block is fed is provided through the rotary base.
In the single wafer processing mechanism configured as described above, the protrusion heights of the positioning portion and the holding member are set to the above ratios, so that turbulent air flow and repelling of the etching solution can be suppressed during high-speed rotation of the wafer. Further, by sending gas from the supply port provided in the block, the atmospheric pressure in the space between the rotating base and the lower surface of the wafer is increased, so that it is possible to prevent the etching solution from entering the lower surface of the wafer.
JP-A-11-289002 (Claims 1 and 2, paragraph [0010], paragraph [0018], paragraph [0019], paragraph [0021])

However, in the conventional single wafer processing mechanism disclosed in Patent Document 1, gas is sent below the wafer to prevent the etching solution from flowing to the lower surface of the wafer. The staying time becomes longer, the portion where the etching solution stays is etched more than necessary, and the shape of the peripheral surface of the wafer that has been chamfered may collapse locally, and the edge portion of the wafer may not be etched uniformly. there were.
Further, in the single wafer processing mechanism shown in the above-mentioned conventional patent document 1, there is a problem that etching gas is scattered and rebounds on the inner wall of the processing apparatus and reattaches to the upper surface of the wafer by feeding gas below the wafer. there were.
The object of the present invention is to prevent the etching solution from flowing to the lower surface of the wafer, to prevent the scattered etching solution from reattaching to the upper surface of the wafer, and to suppress local shape collapse of the edge portion of the wafer. The object is to provide a single wafer etching apparatus.

In the invention according to claim 1, as shown in FIG. 1, a single thin disk-shaped silicon wafer 11 obtained by slicing a silicon single crystal ingot is rotated while being held on a wafer chuck 12. However, this is an improvement of the single wafer etching apparatus that supplies the etching solution 14 to the upper surface of the wafer 11 to etch the upper surface of the wafer 11.
The characteristic configuration is that the chuck 12 is provided with a gas injection mechanism 17 for blowing the etching solution 14 flowing down the edge 11a of the wafer 11 placed on the chuck 12 to the outside in the radial direction of the wafer 11 by gas injection. A ring-shaped guide piece 18, which is an inclined face that is inclined outward in the radial direction of the chuck 12 as the inner peripheral face 18 a faces upward or a vertical face that faces upward, protrudes from the upper part of the outer peripheral edge of the chuck 12. The inclination angle θ of the inner peripheral surface 18a with respect to the horizontal plane is formed in the range of 10 to 90 degrees, the height H of the guide piece 18 is formed in the range of 0.1 to 2 mm, and the lower surface of the wafer 11 placed on the chuck 12 The distance T from the ring-shaped intersection line P between the outer peripheral edge and the lower edge of the edge portion 11a to the inner peripheral edge of the guide piece 18 is set in the range of 0.05 to 5 mm. A.
In the wafer single-wafer etching apparatus described in claim 1, the wafer 11 is first rotated on the surface of the chuck 11 while the wafer 11 is placed on the chuck 12 and held by the gas injection mechanism 17. A high-speed gas flow that flows toward the outer side in the radial direction of the wafer 11 is created in the gap S between the upper surface and the lower surface of the wafer 11. When the etching solution 14 is supplied to the upper surface of the wafer 11 in this state, the etching solution 14 is moved from the supply position to the edge portion 11a side of the wafer 11 due to the centrifugal force generated by the rotation of the wafer 11 within the surface. The wafer 11 is gradually moved while etching the upper surface of the wafer 11, and the edge portion 11 a of the wafer 11 is etched. Then, the etching solution 14 on the wafer 11 is scattered to the outside of the wafer 11 by the centrifugal force accompanying the rotation of the wafer 11. On the other hand, a part of the etching solution 14 that tries to go from the edge portion 11 a of the wafer 11 to the lower surface of the wafer 11 flows in the gap S between the upper surface of the chuck 12 and the lower surface of the wafer 11 in the radial direction outside the wafer 11. By the flow, the wafer 11 is blown away outward in the radial direction and scattered outward of the wafer 11. At this time, since the direction of the etching solution 14 blown off by the high-speed gas flow is changed obliquely upward by the guide piece 18, the scattered etching solution 14 does not adhere to the upper surface of the wafer 11 again.

The invention according to claim 2 is the invention according to claim 1, wherein the guide piece is further provided integrally with the wafer chuck.
In the wafer single wafer etching apparatus according to the second aspect, the guide piece is provided integrally with the wafer chuck, so that the number of parts can be reduced.
The invention according to claim 3 is the invention according to claim 1, characterized in that the guide piece 18 is detachably attached to the wafer chuck 12, as shown in FIG.
In the single wafer etching apparatus according to the third aspect, since the guide piece 18 is detachably attached to the wafer chuck 12, the edge portion 11a is changed when the shape of the edge portion 11a of the wafer 11 is changed. It can be changed to the guide piece 18 having a shape optimal for the shape of 11a. As a result, the direction of the etching solution 14 is changed in an optimum obliquely upward direction by the guide piece 18, so that the scattered etching solution 14 does not adhere to the upper surface of the wafer 11 again.

As described above, according to the present invention, the chuck is provided with a gas injection mechanism for blowing the etching solution flowing down the edge of the wafer on the chuck to the outside in the radial direction of the wafer by gas injection, and the inner peripheral surface is A ring-shaped guide piece, which is an inclined surface that is inclined outward in the radial direction of the chuck as it goes upward or a vertical surface that faces upward, protrudes from the upper part of the outer peripheral edge of the chuck, and the inclination angle and height of the inner peripheral surface of the guide piece In addition, the distance from the line of intersection between the lower peripheral edge of the lower surface of the wafer on the chuck and the lower edge of the edge portion to the inner peripheral edge of the guide piece is set to a predetermined range. Part of the etchant that scatters to the outside of the wafer due to the centrifugal force accompanying the rotation of the wafer, and that tries to wrap around from the edge of the wafer to the lower surface of the wafer. By the high velocity gas stream generated Te, blown radially outward of the wafer. At this time, since the direction of the etching solution is changed obliquely upward by the guide piece, the etching solution can be prevented from flowing around the lower surface of the wafer, and the scattered etching solution does not adhere to the upper surface of the wafer again. As a result, the upper surface of the wafer can be uniformly etched, the time during which the etching solution stays at the edge portion of the wafer can be shortened, and local shape deformation of the edge portion can be suppressed.
Further, if the guide piece is provided integrally with the wafer chuck, the number of parts can be reduced, so that the parts can be easily managed and the assembly workability can be improved.
Further, if the guide piece is detachably attached to the wafer chuck, when the shape of the edge portion of the wafer is changed, it can be changed to a guide piece having an optimum shape for the shape of the edge portion. As a result, it is only necessary to replace the guide piece without changing the chuck, so that the reworking of the etching apparatus associated with the change of the wafer can be performed relatively easily, and the etching solution is obliquely moved upward by the guide piece. Since the direction is changed to the optimum direction, the scattered etching solution does not adhere to the upper surface of the wafer again.

Next, the best mode for carrying out the present invention will be described with reference to the drawings.
<First Embodiment>
As shown in FIG. 1, a single wafer etching apparatus 10 for a silicon wafer includes a wafer chuck 12 that is housed in a chamber and holds a single thin disk-shaped silicon wafer 11 and holds the wafer 11 in a vertical direction. Rotating means 13 for rotating in a horizontal plane around the center line, etching solution supplying means 16 for supplying an etching solution 14 to the upper surface of the wafer 11 held by the chuck 12, and edge portions of the wafer 11 placed on the chuck 12 A gas injection mechanism 17 for blowing the etching solution 14 flowing down through 11a to the outside in the radial direction of the wafer 11 by gas injection; and a protrusion of the chuck 12 on the upper surface of the outer peripheral edge of the chuck 12, and as the inner peripheral surface 18a faces upward. A ring-shaped guide piece 18 which is an inclined surface inclined radially outward or a vertical surface extending upward. . The wafer 11 is obtained by slicing a silicon single crystal ingot, and the outer peripheral edge of the wafer 11, that is, the edge portion 11a, is subjected to convex chamfering processing having a predetermined radius of curvature.

  The chuck 12 has a shaft portion 21a inserted through a disc-shaped base member 19 having a diameter larger than the diameter of the wafer 11 and a through hole 19a formed in the center of the base member 19 so as to extend in the vertical direction. Holding shaft 21. The holding shaft 21 includes the shaft portion 21a, a large-diameter wafer receiving portion 21b formed integrally with the shaft portion 21a on the upper surface of the shaft portion 21a, and the lower surface of the holding shaft 21 at the center of the holding shaft 21. A through hole 21c formed extending vertically to the top and one end communicating with the upper end of the through hole 21c, extending radially outward from the wafer receiving portion 21b around the through hole 21c, and the other end closed. It consists of a plurality of communication holes 21d, a plurality of ring grooves 21e formed concentrically on the upper surface of the wafer receiving portion 21b, and a plurality of small holes 21f that connect the communication holes 21d and the ring grooves 21e. The lower end of the through hole 21c is connected in communication with a vacuum pump (not shown) (FIGS. 1 and 2). The outer diameter of the wafer receiving portion 21b is larger than the outer diameter of the shaft portion 21a and smaller than the outer diameter of the wafer 11, and the wafer 11 is placed on the upper surface of the wafer receiving portion 21b concentrically with the wafer receiving portion 21b. (FIG. 1). When the vacuum pump of the gas injection mechanism 17 is driven and the inside of the through hole 21c becomes negative pressure, the inside of the communication hole 21d, the small hole 21f, and the ring groove 21e becomes negative pressure, and the lower surface of the wafer 11 is the wafer receiving portion of the holding shaft 21. The wafer 11 is held horizontally by the holding shaft 21 by being adsorbed by 21b. The rotating means 13 includes the holding shaft 21 and a drive motor (not shown) that rotates the holding shaft 21. By rotating the holding shaft 21 by the drive motor, the wafer 11 held by the holding shaft 21 is configured to rotate together with the base member 19 and the holding shaft 21. Further, the etching solution supply means 16 is provided above the wafer 11 and has a nozzle 16b provided with a discharge port 16a facing the upper surface of the wafer 11 at the tip, and an etching solution 14 connected to the base end of the nozzle 16b through the nozzle 16b. And a supply pump (not shown) for supplying the discharge port 16a and nozzle moving means (not shown) for moving the nozzle 16b in the horizontal direction.

  On the other hand, the gas injection mechanism 17 includes a ring-shaped injection port 17a provided on the upper surface of the chuck 12 along the circumferential direction of the chuck 12, and a ring-shaped injection port provided on the chuck 12 with an upper end communicating with the injection port 17a. It has the injection groove | channel 17b and the gas supply means (not shown) connected to the injection groove | channel 17b (FIG.1 and FIG.2). The injection port 17a is formed so as to face the lower surface of the wafer 11 near the edge portion 11a. Further, the injection groove 17b is formed so that the diameter becomes smaller as it goes downward, and gradually becomes narrower as it goes upward, so that the injection port 17a becomes narrowest (FIG. 1). The lower portion of the injection groove 17b communicates with one end of four gas supply holes 17c formed from the wafer receiving portion 21b to the shaft portion 21a (FIGS. 1 to 3), and the other end of these gas supply holes 17c is a gas supply means. Connected to. The gas supply means includes a compressor that compresses a gas such as nitrogen gas or air, and the gas compressed by the gas supply means is supplied to the injection port 17a through the gas supply hole 17c and the injection groove 17b.

  The injection groove 17b is provided on the upper surface of the base member 19 by attaching a wafer receiving portion 21b and a taper member 22 concentrically with the base member 19 (FIG. 1). The taper member 22 is a component part of the chuck 12 together with the base member 19 and the holding shaft 21. The outer peripheral surface of the wafer receiving portion 21b is formed in a cone shape whose diameter decreases as it goes downward, and the inner peripheral surface of the taper member 22 is formed in a taper shape whose diameter decreases as it goes downward. After attaching the taper member 22 to the base member 19, the shaft portion 21 a of the holding shaft 21 is inserted into the through hole 19 a, so that a ring shape is formed between the outer peripheral surface of the wafer receiving portion 21 b and the inner peripheral surface of the taper member 22. A gap is formed, and this ring-shaped gap becomes the injection groove 17b. When the wafer 11 is placed and held on the wafer receiving portion 21b of the holding shaft 21, the width of the gap S between the upper surface of the taper member 22 and the lower surface of the wafer 11 is 0.1 to 2 mm, preferably 0.2. Set to ~ 1 mm. The width of the injection port 17a in the horizontal plane is set to 0.1 to 2 mm, preferably 0.2 to 1 mm. Here, the width of the gap S between the upper surface of the taper member 22 and the lower surface of the wafer 11 is limited to a range of 0.1 to 2 mm. This is because there is a risk of contact with the taper member, which is a component, and if it exceeds 2 mm, the effect of the gas injection mechanism 17 is diminished. Further, the reason why the width of the injection port 17a in the horizontal plane is limited to the range of 0.1 to 2 mm is that gas injection is not easy if the width is less than 0.1 mm, and the gas injection supply flow rate is not sufficient if it exceeds 2 mm. Because.

  On the other hand, the guide piece 18 is attached to the upper surface of the outer peripheral edge of the taper member 22 with a fastener such as a screw. The inclination angle θ of the inner peripheral surface 18a of the guide piece 18 with respect to the horizontal plane is formed in the range of 10 to 90 degrees, preferably 30 to 60 degrees, and the height H of the guide piece 18 is 0.1 to 2 mm, preferably 0.1. The distance T from the ring-shaped intersection line P between the outer peripheral edge of the lower surface of the wafer 11 placed on the chuck 12 and the lower edge of the edge portion 11a to the inner peripheral edge of the guide piece 18 is 0.05. It is set to a range of ˜5 mm, preferably 0.2 to 2 mm. When the inclination angle θ of the inner peripheral surface 18a of the guide piece 18 with respect to the horizontal plane is 90 degrees, the inner peripheral surface 18a of the guide piece 18 is not an inclined surface but a vertical surface facing upward. When the inner peripheral surface 18a of the guide piece 18 is a vertical surface, the etching solution 14 may be scattered toward the edge portion 11a of the wafer 11 after hitting the vertical surface. Due to the centrifugal force, a sufficient amount of the etching solution 14 flows out from the center of the wafer 11 toward the outer periphery, so that the etching solution 14 scattered toward the edge portion 11a does not affect the edge portion 11a. . Here, the inclination angle θ with respect to the horizontal plane of the inner peripheral surface 18a of the guide piece 18 is limited to a range of 10 to 90 degrees, and if it is less than 10 degrees, the effect of controlling the gas injection direction by the gas injection mechanism 17 is weak. When the etching solution 14 cannot sufficiently suppress the wraparound to the lower surface of the wafer 11 and exceeds 90 degrees, the gas injection by the gas injection mechanism 17 flows backward to the lower surface side of the wafer 11 or the gas moves toward the edge portion 11a of the wafer 11. This is because the surface of the wafer 11 and the edge 11a are etched. The reason why the height H of the guide piece 18 is limited to the range of 0.1 to 2 mm is that if it is less than 0.1 mm, the effect of controlling the gas injection direction by the gas injection mechanism 17 is weak, and the lower surface of the wafer 11 of the etching solution 14 is reduced. The wraparound to the wafer 11 cannot be controlled sufficiently, and if it exceeds 2 mm, the etching solution 14 scattered outward by the centrifugal force due to the rotation of the wafer 11 hits the inner peripheral surface 18a of the guide piece 18 and then hits the edge portion 11a of the wafer 11. This is because they are scattered and affect the etching of the upper surface of the wafer 11 and the edge portion 11a. Further, the distance T from the ring-shaped intersection line P between the outer peripheral edge of the lower surface of the wafer 11 and the lower edge of the edge portion 11a to the inner peripheral edge of the guide piece 18 is limited to a range of 0.05 to 5 mm. Then, there is a possibility that the guide piece 18 may come into contact with the wafer 11, and it becomes difficult to place the wafer 11 at a predetermined position on the chuck 12, and if it exceeds 5 mm, the effect of controlling the gas injection direction by the gas injection mechanism 17 can be obtained. This is because it is weak, and the wraparound of the etching solution 14 to the lower surface of the wafer 11 cannot be sufficiently suppressed.

  On the other hand, a liquid suction mechanism 23 is provided outside the chuck 12 and the outer peripheral surface of the wafer 11 at a predetermined interval. The liquid suction mechanism 23 includes a liquid receiver 23 a that receives the etching liquid 14 scattered by the centrifugal force accompanying the rotation of the wafer 11 and the etching liquid 14 blown off by the gas injection mechanism 17, and a suction that communicates with the liquid receiver 23 a. Means (not shown) (FIGS. 1 and 2). The liquid receiver 23a opens toward the outer peripheral surfaces of the chuck 12 and the wafer 11, and the opening surface is formed in an arc shape having a central angle of about 90 degrees in a plan view. The liquid receiver 23a is connected to the chuck 12 and the wafer 11. The four are arranged outside the outer peripheral surface of the chuck so as to surround substantially the entire circumference of the chuck 12 and the wafer 11 (FIGS. 1 and 2). The base ends of the suction pipes 23b are connected to the liquid receivers 23a. The suction means is constituted by a vacuum pump or the like, and is connected to the four liquid receivers 23a through the four suction pipes 23b. By this suction means, the etching solution 14 in the liquid receiver 23a is sucked together with the gas through the suction pipe 23b. Further, the liquid receiver 23 a is formed in an inner surface shape having an angle at which the etching liquid 14 does not reach the upper surface of the wafer 11 even if the etching liquid 14 rebounds on the inner surface of the liquid receiver 23 a. In this embodiment, four liquid receivers are arranged outside the outer peripheral surfaces of the chuck and the wafer. However, one, two, three or five can be provided so long as the chuck and the wafer can be surrounded almost entirely. The plurality of suction pipes may be connected in communication with each liquid receiver.

The operation of the wafer single-wafer etching apparatus 10 thus configured will be described.
First, in a state where the wafer 11 is placed on the wafer receiving portion 21b of the holding shaft 21, a vacuum pump connected to the lower end of the through hole 21a of the holding shaft 21 is operated to make the through hole 21c have a negative pressure. To hold the wafer 11. In this state, the drive motor of the rotating means 13 is operated to rotate the wafer 11 together with the base member 19, the holding shaft 21 and the taper member 22 in a horizontal plane. At this time, only the holding shaft 21 may be rotated and the base member 19 and the taper member 22 may be fixed without rotating. Next, the gas supply mechanism of the gas injection mechanism 17 is operated to inject compressed gas composed of nitrogen gas or air from the injection port 17a through the gas supply hole 17c and the injection groove 17b, whereby the upper surface of the taper member 22 and the lower surface of the wafer 11 are injected. A gas flow that flows toward the outside in the radial direction of the wafer 11 is created in the gap S between the upper surface of the wafer 11 and the gap S between the upper surface of the taper member 22 and the lower surface of the wafer 11. Here, since the injection port 17a is narrower than the injection groove 17b, the gas flow becomes high speed. Further, by operating the suction means of the liquid suction mechanism 23, the suction pipe 23b and the liquid receiver 23a are kept at a negative pressure. Next, by operating the supply pump and nozzle moving means of the etching liquid supply means 16, the etching liquid 14 is supplied from the discharge port 16a to the upper surface of the wafer 11 while moving the nozzle 16b in the horizontal direction.

  The etching solution 14 supplied to the upper surface of the wafer 11 is subjected to the edge of the wafer 11 from a location (for example, near the center of the upper surface of the wafer 11) where the etching solution 14 is supplied due to the centrifugal force generated as the wafer 11 rotates in the horizontal plane. After moving gradually while etching the work-affected layer on the upper surface of the wafer 11 toward the portion 11a, the edge portion 11a is etched when the edge portion 11a of the wafer 11 is reached. Then, most of the etching solution 14 on the wafer 11 becomes droplets due to the centrifugal force accompanying the rotation of the wafer 11 and then splashes outside the wafer 11 and enters the liquid receiver 23a. And is discharged out of the chamber.

On the other hand, a part of the etching solution 14 that tries to go from the edge portion 11 a of the wafer 11 to the lower surface of the wafer 11 flows through the gap S between the upper surface of the taper member 22 and the lower surface of the wafer 11 outward in the radial direction of the wafer 11. By the gas flow, it is blown off radially outward of the wafer 11 and scattered outward of the wafer 11. Since the direction of the scattered etching solution 14 is changed obliquely upward by the guide piece 18, it smoothly enters the liquid receiver 23a maintained at a negative pressure, and is discharged out of the chamber through the suction pipe 23b by the negative pressure. Is done. As a result, it is possible to prevent the etching solution 14 from entering the lower surface of the wafer 11. Further, since the scattered etching solution 14 does not adhere to the upper surface of the wafer 11 again, the upper surface of the wafer 11 can be uniformly etched. Furthermore, since the etching solution 14 stays at the edge portion 11a of the wafer 11 for a short time, local deformation of the edge portion 11a can be suppressed.
On the other hand, since the guide piece 18 is detachably attached to the wafer chuck 12, when the wafer 11 having a different shape of the edge portion 11a is placed on the chuck, the guide piece 18 is replaced with a guide piece 18 having an optimum shape for the shape of the edge portion 11a. Just do it. As a result, the direction of the etching solution 14 is changed to an optimum obliquely upward direction by the guide piece 18, so that the scattered etching solution 14 does not adhere to the upper surface of the wafer 11 again.
In the above embodiment, the guide piece is detachably attached to the chuck, but the guide piece may be provided integrally with the chuck. In this case, since the number of parts can be reduced, there is an advantage that the parts can be easily managed and the assembly workability can be improved.
In the above embodiment, the guide piece is attached to the upper surface of the outer peripheral edge of the taper member with a fastener such as a screw. However, the guide piece may be attached to the outer peripheral side surface of the taper member with a fastener such as a screw.

It is a principal part longitudinal cross-section block diagram of the single wafer type etching apparatus of the wafer of this invention embodiment. It is an A arrow line view of Drawing 1 showing an etching device before putting a wafer. It is the BB sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Single wafer type etching apparatus 11 Silicon wafer 11a Edge part 12 Wafer chuck 14 Etching liquid 17 Gas injection mechanism 18 Guide piece 18a Inner peripheral surface of guide piece P Ring-shaped intersection line of lower peripheral edge of wafer and lower edge of edge part θ Inclination angle of the inner peripheral surface of the guide piece H Height of the guide piece T Distance from the ring-shaped intersection line to the inner peripheral edge of the guide piece

Claims (3)

Etching on the upper surface of the wafer (11) while rotating while holding a single thin disk-shaped silicon wafer (11) obtained by slicing a silicon single crystal ingot on the wafer chuck (12) In the single wafer etching apparatus for supplying the liquid (14) and etching the upper surface of the wafer (11),
A gas injection mechanism for blowing an etching solution (14) flowing down the edge (11a) of the wafer (11) placed on the chuck (12) to the outside in the radial direction of the wafer (11) by gas injection ( 17) is provided in the chuck (12),
A ring-shaped guide piece (18) which is an inclined surface inclined radially outward of the chuck (12) or an upward vertical surface as the inner peripheral surface (18a) faces upward is an outer peripheral edge of the chuck (12). Protruding at the top,
An inclination angle (θ) with respect to the horizontal plane of the inner peripheral surface (18a) of the guide piece (18) is formed in a range of 10 to 90 degrees,
The guide piece (18) has a height (H) in the range of 0.1 to 2 mm,
The distance from the ring-shaped intersection (P) between the outer peripheral edge of the lower surface of the wafer (11) placed on the chuck (12) and the lower edge of the edge part (11a) to the inner peripheral edge of the guide piece (18) ( A single wafer etching apparatus for wafers, wherein T) is set in a range of 0.05 to 5 mm.   The wafer single-wafer etching apparatus according to claim 1, wherein the guide piece (18) is provided integrally with the wafer chuck (12).   2. A wafer single wafer etching apparatus according to claim 1, wherein the guide piece is removably attached to the wafer chuck.

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