JP2002231690A - Semiconductor etching method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor wafer etching method and apparatus which can improve the uniformity of planarity of each semiconductor wafer within one batch, and control fluctuation in amount of etching process for the entire surface of each wafer, in order to enhance nanotopography. SOLUTION: During the etching of each silicon wafer W, the adjacent wafers W are rotated mutually in different directions. In the space among the wafers W, flows of etchant are crossed due to normal and reverse rotations of the wafers W. As a result, even among the centers of wafers W, the etchant starts to flow and temperature distribution of etchant in the entire part of the gaps among the adjacent wafers W is uniformized. Accordingly, the planarity of each wafer W in one batch will also be uniformized. Moreover, fluctuations in the amount of etching process for the entire part of the surface of wafer W is also reduced, and the nanotopography can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for etching a semiconductor wafer, for example, a method for wet etching a silicon wafer and an improvement of the apparatus.

[0002]

2. Description of the Related Art Generally, a silicon wafer is subjected to an etching process by a chemical action after being subjected to mechanical processing such as slicing and wrapping. This etching is performed in order to remove the damage generated during the mechanical processing in the preceding step. Here, a conventional etching apparatus will be described with reference to the drawings. FIG. 7 is a perspective view of a state of use of the etching apparatus according to the conventional means. As shown in FIG. 7, the etching apparatus 100 is an apparatus that performs etching by rotating a number of silicon wafers W immersed in an etching solution in an etching bath 101 around respective central axes.

Each silicon wafer W is housed in the wafer magazine 102 in a tandem state in which the respective surfaces are parallel to each other. This wafer magazine 102 is a cylindrical frame-shaped magazine, and has two end plates 103A and 103B spaced apart from each other. These end plates 103A, 103B are provided with three parallel rotating rods 104, 10 arranged at every 120 degrees around the axis thereof.
5,106. Each rotating rod 10
A number of small-diameter guide groove rollers 107 are fixed to the 4, 105, and 106 at a constant pitch in the axial direction.

[0004] A large number of silicon wafers W are formed in a space inside a wafer magazine 102 defined by these three rotating rods 104, 105 and 106, and a guide groove roller 107 corresponding to an outer peripheral portion of each wafer. The wafer magazines 102 are inserted in the grooves and are arranged at a constant pitch in the length direction of the wafer magazine 102. This wafer magazine 10
2 is moved up and down by a magazine elevating device (not shown) in which tips of a pair of elevating arms 109A and 109B are fixed to the outer surfaces of both end plates 103A and 103B. Each end plate 103
A, 103B, the center of the outer surface, the wafer magazine 1
Rotation shafts 103a, 103a serving as rotation centers of 02 are rotatably projected via bearings, respectively. The tip of each rotating shaft 103a, 103a is
A, 109B penetrate the lower end and protrude outward.

Next, a rotating means 110 for rotating a large number of silicon wafers W inside the wafer magazine 102 will be described. The rotating means 110 has a rotating motor 111 fixed to the lifting arm 109A side of a magazine lifting device (not shown) and rotating the rotating rods 105 and 106, respectively. Rotary motor 111
A cup-shaped gear 112 is fixed to the lower end of the output shaft 111a arranged downward. Lifting arm 10
On the outer surface of 9A, three small-diameter gears 113, 114, and 115 are arranged in mesh with each other in the arm length direction.

The cup-shaped gear 112 is meshed with the uppermost small-diameter gear 113, and the tip of the rotating shaft 103 a that projects outside through the lifting / lowering arm 109 A is engaged with the lowermost small-diameter gear 115. The drive gear 116 fixed to the portion is engaged. On the other hand, between the end plate 103A of the rotating shaft 103a and the elevating arm 109A, the large-diameter gear 1
17 is fixed. The large-diameter gear 117 has an end plate 10
The two rotating rods 10 penetrating through 3A and projecting to the outside
Small-diameter rod drive gears 118 and 119 fixed to one ends of the gears 5 and 106 are meshed with each other. In FIG. 7, reference numerals 120, 120 denote a pair of guide rods that receive the silicon wafer W from below and assist the rotation of the silicon wafer W. 121, 121 are the guide rods 12
The guide gear is fixed to one end of the first and second gears 120 and 120 and meshes with the large-diameter gear 117.

When etching the silicon wafer W,
The rotating motor 111 rotates the cup-shaped gear 112 while circulating and supplying the etchant into the etching tank 101. The rotational force of the small-diameter gears 113, 114, 1
15, the drive gear 116, the large-diameter gear 117, and the rod drive gears 118 and 119, and the two rotating rods 105 and 106.
To rotate. At this time, the guide rods 120 also rotate via the guide gears 121. Thus, the three rotating rods 104, 105, 106
A large number of silicon wafers W rotate around their respective central axes in the same rotation direction in the internal space defined by the above.

[0008]

However, according to this conventional etching apparatus, since the rotation directions of the respective silicon wafers W are the same as described above, the etching bath 101 is formed in a narrow space between the adjacent silicon wafers W. The flow of the etchant supplied inside was easy to stagnate. In particular, the etchant hardly flows at the center of the silicon wafer W, and the temperature distribution of the etchant over the entire gap between the adjacent silicon wafers W is not uniform. As a result, the flatness of a large number of silicon wafers W stored in the wafer magazine 102 within one batch is not uniform. Further, in each of the silicon wafers W, the amount of etching on the entire surface of the wafer varied, and the nanotopography was reduced. Nanotopography is a phenomenon in which, when a silicon wafer W is attracted to a wafer holding plate in a photolithography process in a device process, undulations on the back surface of the wafer are transferred to the mirror-polished wafer surface. This nanotopography reduces the resolution of the exposure,
Device yield is reduced.

[0009]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a semiconductor wafer in which the flatness of each semiconductor wafer in one batch can be made uniform, the variation in the etching amount over the entire surface of each semiconductor wafer can be suppressed, and the nanotopography can be enhanced. It is an object of the present invention to provide an etching method and an apparatus therefor.

[0010]

Means for Solving the Problems The invention according to claim 1
Is to flatten multiple semiconductor wafers
Each column is immersed in an etching solution in a column,
Rotate wafers around their respective central axes for etching
In the method of etching a semiconductor wafer to be
Semiconductor wafers in different directions
This is a method for etching a semiconductor wafer. This semiconductor
Examples of the wafer include a silicon wafer.
Can be As an etching solution, for example, HF, H
NO_Three, CH_ThreeCOOH, H_TwoO _TwoMixed acid solution of phosphoric acid, N
Alkali etching of aOH, KOH, ammonia etc.
Liquid and the like. During etching, this semiconductor wafer
Ha usually stored multiple sheets in a wafer magazine
Etched in the state. The rotation direction of the semiconductor wafer is
Not limited. In short, adjacent semiconductor wafers
Rotation in different directions (forward or reverse)
Just fine. The rotation speed of the semiconductor wafer is not limited. Through
Usually, the rotation speed is independent of the forward direction and the reverse direction.
And 5 to 50 rpm. The above matters are described in claim 2
Also applies.

According to a second aspect of the present invention, there is provided an etching tank for storing an etching solution, and a plurality of semiconductor wafers which are taken in and out of the etching tank and are stored in a tandem state with their surfaces parallel to each other. A wafer magazine, and a normal rotation unit for normally rotating every other semiconductor wafer among the semiconductor wafers housed in the wafer magazine around respective central axes, and a semiconductor wafer remaining without normal rotation at each center. And a reversing means for reversing around an axis. The normal rotation means and the reverse means of the semiconductor wafer are not limited. For example, each semiconductor wafer housed in the wafer magazine may be rotated around its central axis by the rotational force of an electric motor.

[0012]

According to the present invention, each semiconductor wafer is immersed in an etching solution to etch both the front and back surfaces. In this case, adjacent semiconductor wafers are rotated in directions different from each other (in claim 2, the normal rotation means and the reversal means are used). As a result, in the gap between the semiconductor wafer and the semiconductor wafer, a flow toward one of the etchants accompanying the movement of the semiconductor wafer rotating forward and a flow of the etchant toward the other accompanying the movement of the semiconductor wafer rotating appear. Some of them intersect with each other and become turbulent. Therefore, while the etchant hardly flows between the center portions of the wafer in the past, the etchant flows. As a result, the temperature distribution of the etchant over the entire gap between adjacent semiconductor wafers becomes uniform. Therefore, the flatness of each semiconductor wafer in one batch can be made uniform, and the variation in the etching amount over the entire surface of each semiconductor wafer can be reduced, and the nanotopography can be improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. First, a semiconductor wafer etching apparatus according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a semiconductor wafer etching apparatus according to a first embodiment of the present invention. FIG. 2A is an enlarged sectional view of a main part showing a use state of a driven rotary rod in a semiconductor wafer etching apparatus according to a first embodiment of the present invention. FIG. 2B is an enlarged sectional view of a main part showing a use state of a rotating rod for normal rotation of the wafer in the semiconductor wafer etching apparatus according to the first embodiment of the present invention. FIG. 2C is an enlarged sectional view of a main part showing a use state of a rotating rod for reversing the wafer in the semiconductor wafer etching apparatus according to the first embodiment of the present invention. FIG. 3A shows the first embodiment of the present invention.
It is a principal part enlarged longitudinal sectional view which shows the normal rotation state of the wafer by the apparatus of the semiconductor wafer which concerns on Example. FIG. 3 (b)
FIG. 2 is an enlarged longitudinal sectional view of a main part showing a semiconductor wafer reversing state by the semiconductor wafer apparatus according to the first embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes an etching apparatus for a semiconductor wafer (hereinafter, referred to as an etching apparatus 10).
It is an apparatus that performs etching by rotating it around each central axis. Each silicon wafer W is stored in the wafer magazine 12 in a tandem state in which the respective surfaces are parallel to each other. The wafer magazine 12 is a cylindrical frame-shaped magazine having two end plates 13A and 13B spaced apart from each other. These end plates 13A,
13B is 3 arranged at every 120 degrees around its axis.
The parallel fixed rod 14, the normal rotation rod 15, and the reversing rod 16 are connected to each other.

Among them, the fixed rod 14 arranged on the upper side
Are provided with a large number of small-diameter driven groove rollers 17A... At a constant pitch in the axial direction thereof (FIG. 2A). On the other hand, the forward rotation rod 15
And a plurality of driven groove rollers 17 at the same pitch in the corresponding axial direction.
A and the driving groove roller 1 fixed to both rods 15 and 16
7B are alternately arranged. That is, the forward rotation rod 15 has the driving groove roller 17 based on the end on the side of the end plate 13A.
B, and the driven groove rollers 17A are arranged in this order (FIG. 2).
(B)). On the contrary, with the reversing rod 16,
The driven groove rollers 17A, the driven groove rollers 17B,... Are arranged in this order with reference to the end on the side of the end plate 13A (FIG. 2).
(C)). Therefore, a large number of silicon wafers W are formed in the inner space of the wafer magazine 12 defined by these three rods 14, 15, 16 and in the grooves of the groove rollers 17A, 17B. Inserted,
The wafer magazines 12 are arranged at a constant pitch in the length direction.

The wafer magazine 12 has both end plates 13A,
The magazine 13 is moved up and down by a magazine elevating device (not shown) in which tips of a pair of elevating arms 19A and 19B are fixed to the outer surface of 13B. At the center of the outer surface of each end plate 13A, 13B,
A rotating shaft 13a serving as a rotating center of the wafer magazine 12,
13a are rotatably projected via bearings, respectively. The distal ends of the rotating shafts 13a, 13a protrude outward through the lower ends of the lifting arms 19A, 19B.

Next, the rotation means 20 for rotating each silicon wafer W forward or in the wafer magazine 12 will be described. The rotating means 20 is fixed to a lifting arm 19A of a magazine lifting device (not shown). The rotating means 20 has a rotating motor (forward rotating means, reversing means) 21 for rotating the rods 15 and 16. The output shaft 21a of the rotary motor 21 is arranged downward, and a cup-shaped gear 22 is fixed to the lower end of the output shaft 21a. On the other hand, on the outer surface of the lifting arm 19A, the three small-diameter gears 23,
24 and 25 are arranged. Of these, the cup-shaped gear 22 is meshed with the uppermost small-diameter gear 23, and the lowermost small-diameter gear 25 is fixed to the tip of the rotating shaft 13 a that penetrates the elevating arm 19 </ b> A and projects outside. Drive gear 26 is engaged.

A large-diameter gear 27 is fixed between the end plate 13A of the rotating shaft 13a and the lifting arm 19A. On the other hand, the forward rotation rod 15 and the reverse rod 16
Has one end protruding outside through the end plate 13A. Of these, one end of the normal rotation rod 15
A small-diameter rod drive gear (forward rotation means) 28 meshing with the large-diameter gear 27 is fixed, and a small-diameter rod drive gear (reversal means) 29 is fixed to one end of the reversing rod 16.
Note that one end of the reversing rod 16 to which the rod drive gear 29 is fixed protrudes outside slightly longer than one end of the normal rotation rod 15. A short rotating pin 30 is rotatably supported near the reversing rod 16 of the end plate 13A. A small-diameter first reversing gear (reversing means) 3 meshed with the large-diameter gear 27 is provided at the base of the rotating pin 30.
1 is fixed. A small-diameter second reversing gear (reversing means) 32 is fixed to the tip of the rotating pin 30. The second reversing gear 32 is meshed with the rod drive gear 29.

A pair of forward guide rods 33A and reverse guide rods 33B, which are spaced apart from each other, are provided between the rods 15, 16 in the outer peripheral portions of the end plates 13A, 13B. It is suspended horizontally.
The ends of the guide rods 33A and 33B on the side of the end plate 13A protrude outward from the end plate 13A. The small-diameter gear 60 that directly meshes with the large-diameter gear 27 is fixed to the protruding portion of the forward rotation guide rod 33A. A reversing gear 62 that is indirectly meshed with the large-diameter gear 27 is fixed to the protruding portion of the reversing guide rod 33B via a small-diameter intermediate gear 61. Therefore, when the large diameter gear 27 rotates, the forward rotation guide rod 33A forcibly rotates forward through the small diameter gear 60, while the intermediate gear 61
And the reversing guide rod 33B is forcibly reversed via the reversing gear 62.

As shown in FIG. 3, the forward rotation guide rod 33
A has a number of annular grooves 33a formed at a constant pitch in the axial direction. On the other hand, a number of annular grooves 33b are also formed on the reversing guide rod 33B at a constant pitch in the axial direction. The term "constant pitch" as used herein means that the holding interval for two silicon wafers W is one pitch. Moreover, the one annular groove 33a and the other annular groove 33b are positioned in the rod axial direction by a holding interval for one silicon wafer W so that adjacent ones are staggered in plan view. It is out of alignment.
Therefore, each of the normally rotating silicon wafers W enters the corresponding annular groove 33a,..., While each of the inverted silicon wafers W enters the corresponding annular groove 33b. As a result, in the outer peripheral surface of the rotating silicon wafer W, the frictional resistance is increased in a portion that comes into contact with the surface on which the annular grooves 33a,. For this reason, the normally rotating silicon wafer W does not come into contact with the outer peripheral surface of the reversing guide rod 33B, and the annular groove 33a having a large frictional resistance is formed.
It rotates forward with the rotation of the attached forward rotation guide rod 33A. On the other hand, the reversing silicon wafer W does not come into contact with the outer peripheral surface of the normal rotation guide rod 33B, but rotates normally with the rotation of the reversal guide rod 33B with the annular groove 33b having a large frictional resistance.

Next, a method of etching a silicon wafer W using the etching apparatus 10 according to the first embodiment will be described. As shown in FIG. 1, during the etching, the etchant is circulated and supplied into the etching tank 11,
The rotary motor 21 rotates the cup-shaped gear 22.
The rotational force is reduced by the small-diameter gears 23, 24, 25 and the drive gear 2
6. The power is transmitted to the rod drive gear 28 via the large-diameter gear 27 to rotate the normal rotation rod 15. On the other hand, the rotational force of the large-diameter gear 27 reaches the rod drive gear 29 via the first reversing gear 31, the rotating pin 30, and the second rotating gear 32, and causes the reversing rod 16 to move in the opposite direction to the normal rotation rod 15. Rotate in the direction.

By the rotation of the forward rotation rod 15, each driving groove roller 17B fixed to the forward rotation rod 15 rotates. On the other hand, by the rotation of the reversing rod 16, each driving groove roller 17B fixed to the reversing rod 16 rotates.
At this time, the forward-rotation rod 15 has a main groove roller 17B, a driven groove roller 17A,... With reference to the end on the side of the end plate 13A.
(FIG. 2 (b)), the reverse rod 16 has a reverse groove roller 17A, a main groove roller 17B,... With reference to the end on the side of the end plate 13A. (FIG. 2 (c)). In addition, the fixed rod 14
, Only the driven groove rollers 17A are arranged. As a result, in the internal space of the wafer magazine 12 defined by these three rods 14, 15, 16, the first silicon wafer W is arranged in the order based on the end on the side of the end plate 13 A. The odd-numbered third, fifth,... Sheets rotate forward (FIG. 3A), and the even-numbered sheets, second, fourth, and sixth sheets, reverse (FIG. 3B). That is, the adjacent silicon wafers W rotate in directions different from each other, and each of the driven groove rollers 17A disposed on the fixed rod 14, the normal rotation guide roller 33A, and the reverse guide roller 33B. In accordance with the normal rotation or reversal of each silicon wafer W, the silicon wafer W rotates in a predetermined direction.

As described above, as each of the silicon wafers W rotates, the gap between the silicon wafers W causes a flow toward one of the etchants accompanying the movement of the normally rotating silicon wafer W and a reverse flow. And the flow toward the other side of the etchant accompanying the movement of the silicon wafer W appears, and a part thereof intersects with each other to become a turbulent flow. Therefore, while the etchant has hardly flowed between the center portions of the silicon wafer in the past, the etchant flows in the first embodiment. Therefore, the temperature distribution of the etchant over the entire gap between the adjacent silicon wafers W becomes uniform. As a result, the flatness of each silicon wafer W in one batch can be made uniform. In addition, it is possible to reduce the variation in the etching amount on the entire surface of each silicon wafer W, thereby improving the nanotopography.

Next, a method and an apparatus for etching a semiconductor wafer according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a schematic perspective view of a wafer magazine used for a semiconductor wafer etching apparatus according to a second embodiment of the present invention. FIG. 5 is an enlarged side view of a main part of a wafer magazine used in a semiconductor wafer etching apparatus according to a second embodiment of the present invention.

As shown in FIGS. 4 and 5, a semiconductor wafer etching apparatus 50 according to the second embodiment uses a pair of roller forward / reverse rods (forward rotation means) instead of the forward rotation rods 15 and the reverse rods 16. ) 51, 51 are examples.
The roller forward / reverse rods 51, 51 are driven groove rollers 17C rotatably inserted into the two roller forward / reverse rods 51, 51, and a main groove roller fixed to both roller forward / reverse rods 51, 51. 17B... Are alternately arranged. A predetermined number of external teeth are formed on the outer peripheral portion of each driven groove roller 17C.

A pair of reversing drive rods (reversing means) 53, 53 parallel to the axis of the corresponding roller reversing rods 51, 51 are provided near the respective roller reversing rods 51, 51.
Are arranged in a bridging state between the end plates 13A and 13B. One end of the both rollers forward / reverse rod 51, 51
It protrudes outward from the end plate 13A. On each protruding part,
Small-diameter gears 51a, 51a meshing with the large-diameter gear 27 are fixed. One ends of the reversing drive rods 53, 53 protrude outward from the end plate 13A longer than the roller normal reversing rods 51, 51. Small diameter gears 53a, 53a are fixed to the tips of these protruding portions. A pair of reversing gears 54 is supported on the outer peripheral portion of the end plate 13A and between the corresponding roller normal reversing rods 51, 51 and reversing drive rods 53, 53, respectively.
The width of the external teeth of each of the reversing gears 54 is long, and the original portions of the external teeth mesh with the small-diameter gears 51a, 51a.
The tip of each external tooth meshes with the small-diameter gears 53a. The reversing drive rods 53, 53 are provided with reversing drive gears 55 meshing with the external teeth of the driven groove rollers 17C facing each other.
Are fixed at a constant pitch in each axial direction.

Therefore, when the large-diameter gear 27 rotates,
Through each small-diameter gear 51a, a roller forward / reverse rod 5
1, 51 rotate forward. These roller forward / reverse rods 5
The rotational force of the first and the first 51 is transmitted to both the reversing drive rods 53 via the two reversing gears 54 and the small diameter gears 53a and 53a. Thereby, each reversing drive rod 53, 53
Rotates in the same normal rotation direction as the roller normal reversing rods 51, 51 (see FIG. 4). As a result, each reversing drive gear 55
Rotate in the forward direction, and the driven groove rollers 17C meshing with the reversing drive gears 55 reverse (see FIG. 5).

The forward guide rod 52A and the reverse guide rod 52B rotate inward as in the first embodiment. One end of each of the guide rods 52A, 52B protrudes outward from the end plate 13A. Each projection has a small-diameter gear 52
a and 52b are fixed. On the outer surface of the end plate 13A,
A reversing gear 56 meshing with the large-diameter gear 27 and the small-diameter gear 52b is supported near the reversing guide roller 52B. Therefore, the rotation of the large-diameter gear 27 causes the small-diameter gear 5 to rotate.
The forward rotation guide rod 52A rotates forward via 2a. On the other hand, the reversing gear 56 also rotates, and the reversing guide rod 52B is reversed by the small-diameter gear 52b. Therefore, both guide rods 52A and 52B forcibly rotate inward.

Next, a method of etching a semiconductor wafer using the etching apparatus 50 according to the second embodiment will be described. At the time of etching, when the large-diameter gear 27 is rotated by the rotary motor 21, the two rollers forward / reverse rod 51,
51 rotates forward and the respective driving groove rollers 17B... Rotate forward, while the reversing drive rods 53 also rotate forward via the reversing gears 54. As a result, similarly to the first embodiment, the respective reversing drive gears 55 fixed to the reversing drive rods 53 are rotated forward, and the respective driven groove rollers 17C are rotated.
Are reversed (see FIG. 5). When the large-diameter gear 27 rotates, the forward rotation guide rod 52A rotates forward.
The reversing guide rod 52B is reversed via the reversing gear 56.

As described above, in the second embodiment, each of the driving groove rollers 17B is rotated forward by the forward rotation of the pair of roller forward and reverse rods 51, 51, while the pair of reverse drive rods 53, 53 are rotated. , The driven groove rollers 17C... Are forcibly inverted, so that a large number of silicon wafers W stored in the wafer magazine 12 can be rotated forward or every other with little slip during rotation. Can be inverted. Other configurations, operations, and effects are the same as those of the first embodiment, and thus description thereof is omitted.

Next, a method and an apparatus for etching a semiconductor wafer according to a third embodiment of the present invention will be described with reference to FIG. FIGS. 6A and 6B are explanatory views showing a step of swinging a semiconductor wafer in a method of etching a semiconductor wafer according to a third embodiment of the present invention.

As shown in FIG. 6, the semiconductor wafer etching apparatus 60 according to the third embodiment swings the silicon wafers W together in the vertical direction instead of the guide rods 52A and 52B. This is an example using moving rods 62A and 62B. The oscillating rods 62A and 62B are rods each having a substantially bale-shaped cross section.
Synchronizes the undulation of the bale and makes inward turns. One end of each of the swinging rods 62A and 62B protrudes outward from the end plate 13A. The small diameter gears 52a, 5
2b is fixed. The large-diameter gear 27 and the small-diameter gear 52 are provided on the outer surface of the end plate 13A near the swing roller 62B.
A reversing gear 56 meshing with b is pivotally supported. Therefore, the rotation of the large-diameter gear 27 causes the swing rod 62A to rotate forward via the small-diameter gear 52a. On the other hand, the reversing gear 56
Also rotates, and the swing rod 62B is inverted by the small diameter gear 52b. Therefore, both swinging rods 62A and 62B rotate inward at the timing of the undulation of each bale shape described above.

Next, a method for etching a semiconductor wafer using the etching apparatus 60 according to the third embodiment will be described. When the large-diameter gear 27 is rotated by the rotary motor 21 during etching, the swing rod 62A rotates forward, while the swing rod 62B reverses via the reverse gear 56. As a result, both swinging rods 62A and 62B rotate with the timing of the undulation of each bale shape being matched (FIGS. 6 (a) to 6 (d)). Therefore, the swing rod 62
Each of the silicon wafers W, the lower ends of which are supported by A and 62B, swings in the vertical direction by the distance a between the sideways posture and the standing posture of the bale. Such a series of operations is constantly repeated during the etching. As a result, unevenness in etching of each silicon wafer W can be reliably prevented at low cost. Other configurations, operations, and effects are the same as those of the second embodiment, and thus description thereof is omitted.

[0034]

According to the present invention, since the adjacent semiconductor wafers are etched while being rotated in different directions, the temperature distribution of the etchant over the entire gap between the adjacent semiconductor wafers is made uniform, Thereby, the flatness of each semiconductor wafer can be made uniform within one batch. In addition, the variation in the etching amount on the entire surface of each semiconductor wafer is reduced, and the nanotopography can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a semiconductor wafer etching apparatus according to a first embodiment of the present invention.

FIG. 2A is an enlarged sectional view of a main part showing a use state of a driven rotary rod in a semiconductor wafer etching apparatus according to a first embodiment of the present invention. (B)
FIG. 2 is an enlarged sectional view of a main part showing a use state of a rotating rod for normal rotation of the wafer in the semiconductor wafer etching apparatus according to the first embodiment of the present invention. (C) is an enlarged sectional view of a main part showing a use state of a rotating rod for reversing the wafer in the semiconductor wafer etching apparatus according to the first embodiment of the present invention.

FIG. 3A is an enlarged vertical cross-sectional view of a main part showing a normal rotation state of the semiconductor wafer device according to the first embodiment of the present invention. FIG. 2B is an enlarged longitudinal sectional view of a main part showing a wafer reversing state by the semiconductor wafer apparatus according to the first embodiment of the present invention.

FIG. 4 is a schematic perspective view of a wafer magazine used for a semiconductor wafer etching apparatus according to a second embodiment of the present invention.

FIG. 5 is an enlarged side view of a main part of a wafer magazine used for a semiconductor wafer etching apparatus according to a second embodiment of the present invention.

FIGS. 6A and 6B are explanatory views showing a swinging process of a semiconductor wafer in a semiconductor wafer etching method according to a third embodiment of the present invention.

FIG. 7 is a perspective view of a use state of an etching apparatus according to a conventional means.

[Explanation of symbols]

 10, 50, 60 semiconductor wafer etching apparatus, 11 etching tank, 12 wafer magazine, 21 rotation motor (forward rotation means, reversing means), 28 rod drive gear (forward rotation means), 29 rod drive gear (reversal means), 31 first reversing gear (reversing means), 32 second reversing gear (reversing means), 51, 51 roller forward reversing rod (forward rotating means), 53, 53 reversing driving rod (reversing means), W silicon wafer (Semiconductor wafer).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuyuki Shimizu 1-5-1, Otemachi, Chiyoda-ku, Tokyo Within Mitsui Material Silicon Co., Ltd. (72) Fumihara Fukuhara 1-chome, Otemachi, Chiyoda-ku, Tokyo No.5-1 Mitsubishi Materials Silicon Co., Ltd. (72) Inventor Yukio Sekiya 2-3-13 Edobori, Nishi-ku, Osaka-shi, Osaka F-term in Hashimoto Sansho Co., Ltd. 5F043 AA02 BB02 EE35 EE40 FF07

Claims (2)

[Claims] 1. A method of immersing a plurality of semiconductor wafers in an etching solution in a state of tandem with their surfaces parallel to each other,
A method of etching a semiconductor wafer, wherein each semiconductor wafer is rotated around its respective central axis for etching, wherein adjacent semiconductor wafers are rotated in mutually different directions. 2. An etching tank for storing an etching solution, a wafer magazine which is inserted into and removed from the etching tank, and stores a plurality of semiconductor wafers in a tandem state in which respective surfaces are parallel to each other, and is stored in the wafer magazine. A rotating means for rotating every other semiconductor wafer around each central axis of the semiconductor wafers, and a reversing means for rotating the remaining semiconductor wafers without rotating around the respective central axes. Equipment for etching semiconductor wafers.