JP3529030B2 - Semiconductor wafer etching method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for etching a semiconductor wafer and an apparatus therefor, for example, a method for wet etching a silicon wafer and an improvement for the apparatus.

[0002]

2. Description of the Related Art Generally, a silicon wafer is subjected to mechanical processing such as slicing and lapping, and then subjected to chemical etching. This etching step is performed for the purpose of removing damage caused by the machining in the previous step. At the same time, it is required that the appearance, flatness, surface roughness, etc. of the etched silicon wafer be regulated to a certain extent for later polishing or the like. Therefore, various innovations have been made in the past regarding the etching method and the jig used for the etching. In particular, with the recent trend of larger diameter semiconductor wafers, surface defects (unevenness) due to the reaction gas from the surface of the semiconductor wafer have become a serious problem.

As a conventional semiconductor wafer etching apparatus, for example, the one described in JP-A-4-151837 is known. In this device, two main rollers having a plurality of engagement grooves for supporting the wafer formed in the axial direction and a pressing member having a plurality of similar engagement grooves formed in the axial direction are provided in a drum frame-shaped casing. They are arranged parallel to each other and rotatable. The main roller is rotationally driven by the drive mechanism. Between the main rollers in the casing, and
An auxiliary roller is rotatably provided at an appropriate angular position between the main roller and the pressing member. The auxiliary roller is driven by a drive mechanism. In this apparatus, by rotating the main roller and the auxiliary roller by the drive mechanism, a large number of wafers housed in the casing are collectively rotated around the central axis thereof.

[0004]

However, in such a semiconductor wafer etching apparatus, as the diameter of the semiconductor wafer increases, uneven etching occurs on the front and back surfaces of the semiconductor wafer. This is because the wafer is always supported or held by abutting or sliding contact with the same outer peripheral portion via the engaging groove, so that the amount of etching liquid acting on this supporting portion (engaging groove) is , Because it is less than other parts. Further, it has been difficult to suppress the unevenness of the flatness of each wafer surface within a jig that holds a large number of semiconductor wafers. This is because the rotation speed of each wafer is not always constant and the reaction with the etching solution varies among the wafers. Further, in the conventional etching apparatus, the etching liquid is supplied into the etching tank through a single small supply hole formed in the central portion of the bottom plate of the etching tank, that is, directly below the casing. Therefore, the flow of the etching liquid toward both ends of the casing is weaker than that in the central portion of the casing. As a result, in the axial direction of the casing, the wafers contained in the casing had etching variations.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a semiconductor wafer etching method and apparatus capable of producing a semiconductor wafer having a high flatness and a uniform surface condition.

[0006]

The invention according to claim 1
Is a semiconductor wafer dipped in the etching solution of the etching bath.
Rotate the wafer to etch the semiconductor wafer
Do not rotate this semiconductor wafer in the
At the same time, in the direction of the rotation axis of this wafer,
Swing horizontally and vertically in a plane perpendicular to
And left in the plane perpendicular to the axis of rotation of this wafer
The etching solution is blown from the right side, and the above-mentioned etch
The etching liquid is sprayed from almost the entire bottom surface of the etching tank.
And the bar placed under the semiconductor wafer.
A semiconductor wafer that bubbles while rocking a blur tube
This is a method of etching the c. Examples of this semiconductor wafer include a silicon wafer. Also,
As the etching liquid, for example, HF, HNO ₃ , CH ₃
COOH, H ₂ O ₂ , mixed acid solution of phosphoric acid, NaOH, KO
Examples thereof include alkaline etching solutions such as H and ammonia. During etching, this semiconductor wafer is usually
The plurality of wafers are etched in a wafer magazine.

Rotational direction and rotational speed of semiconductor wafer
Is not limited. Normally, this rotation speed is 5-50 rpm
Is. These matters are described in claims 2 to 4.
This also applies to the invention. Further, the swing width of the semiconductor wafer in each swing direction is not limited. For example, the swing width may be about 0.5 mm to 10 cm. The swing width in each direction may be the same width or different widths. These matters also apply to each invention described in claim 2, claim 3, and claim 4 .

Blowout of etching liquid onto the wafer
The direction may be only the left-right direction in a plane perpendicular to the rotation axis of the wafer, only the tilt direction, or both the left-right direction and the tilt direction. The tilt direction here means
It may be in any direction of upward inclination and downward inclination. The etching liquid blowing speed is not limited. However, it is preferable that the flow rate from the inclined direction is 10 to 800 liters / minute. In addition, these matters are claimed in claim 2, claim 3, claim
It also corresponds to 4 .

The term " substantially the entire area of the bottom surface of the etching bath" as used herein means that the entire area of the bottom surface may be used, or the area may be slightly narrower than this. Further, blowing up the etching liquid substantially evenly means blowing up the etching liquid at the same flow rate or a flow rate close to this flow rate over substantially the entire bottom surface. The etching liquid blowing speed is not limited. However, the flow rate from the bottom surface is preferably 10 to 800 liters / minute. Note that these matters also correspond to claim 3 .

According to a second aspect of the invention, the inside of the etching tank is
Rotate the semiconductor wafer immersed in the etching solution of
For etching semiconductor wafers
Then, while rotating this semiconductor wafer,
Wafer rotation axis direction, the plane perpendicular to this rotation axis
Swing to the left and right and up and down in the plane, and
Etching is performed from the left and right in a plane perpendicular to the wafer rotation axis.
The etching liquid is blown out and the bottom of the etching bath is
Etching liquid is applied from the vicinity of the part that faces the semiconductor wafer.
It is blown up and placed below the semiconductor wafer.
The semiconductor window that bubbles while swinging the bubbler tube
This is a wafer etching method. The vicinity of the portion of the bottom surface of the etching tank facing the semiconductor wafer may be only a portion facing the semiconductor wafer, or a range slightly larger or smaller than this facing portion. Further, the etching liquid blowing speed is not limited. However, 10
800 l / min is preferred. It is preferable that the etching liquid is blown up from the vicinity of the portion facing the semiconductor wafer almost uniformly over the entire region. Note that these matters also correspond to claim 4 .

The bubbler tube is a tube for bubbling by blowing a gas such as N ₂ gas into the etching solution. The thickness and number of bubbler tubes are not limited. This tube may be rocked just below the semiconductor wafer, or may be rocked beyond this vicinity. Also,
The swing width of this bubbler tube is not limited. However, the swing width is usually about 10 to 300 mm. Further, the swinging direction of the bubbler tube is not limited. For example, it may be the rotation axis direction of the semiconductor wafer, or the left-right direction and the up-down direction in a plane perpendicular to the rotation axis. These matters also apply to claims 3 and 4 .

[0012]

[0013]

The means for rotating the semiconductor wafer is not limited. For example, the wafer magazine containing the semiconductor wafers may be rotated in the direction of the rotation axis of the wafer by the rotating force of the electric motor. Regarding this matter,
It also corresponds to claims 3 to 4 . Wafer swinging means for swinging the semiconductor wafer is not limited. For example, a cam type rocking mechanism, a link type rocking mechanism, etc. may be mentioned. Further, the three swinging directions may be swung by using swinging mechanisms each having a separate drive source, or one drive source may be formed by using a power transmission system using gears, belts, chains, or the like. Therefore, the semiconductor wafers may be collectively swung in the respective directions. These matters, 請
It also corresponds to claim 3 and claim 4 .

The side blowing means is not limited as long as it can blow the etching liquid onto the semiconductor wafer from the left and right directions within a plane perpendicular to the rotation axis of the semiconductor wafer. For example, an etching solution supply device that blows out the etching solution stored in an external storage tank into the etching tank through a nozzle by a pressure pump may be used. It should be noted that the direction in which the etching solution is blown from the side includes the tilt direction. This matter is subject to claim 3, contract
It also corresponds to Requirement 4 .

The uniform blowing means is not limited as long as it can blow the etching liquid into the etching tank substantially uniformly from almost the entire bottom surface of the etching tank. For example, a perforated plate that is arranged at the bottom of the etching tank and divides the inner space of the tank into upper and lower parts, and a pressure feed pump that supplies the etching liquid in the external storage tank into the lower space partitioned by the perforated plate. May be included. The etching liquid supplied into the lower space by the pressure-feeding pump is blown up at a substantially uniform flow rate over the entire etching tank through the holes formed in substantially the entire area of the perforated plate. These matters are claimed in claim 3.
Also applies.

The facing part blowing means is not limited as long as the etching liquid can be blown into the etching tank from the vicinity of the part facing the semiconductor wafer. For example, a partition plate placed at the bottom of the etching tank to partition the inner space of the tank into upper and lower parts, and a pump for supplying the etching liquid in the external storage tank into the lower space partitioned by the partition plate. And the like may be used. A relatively large blow-up port is formed near the portion of the partition plate facing the semiconductor wafer. The etching liquid supplied into the lower space by the pressure pump is blown up into the etching tank through the blow-up port of the partition plate. At this time, the perforated plate may be arranged at the blow-up port. By doing so, the etching liquid can be blown up substantially uniformly over substantially the entire area of the blow-up port. These matters also apply to claim 4 .

The bubbler tube swinging means is not limited as long as it can swing the bubbler tube below the semiconductor wafer. For example, a link mechanism, a cam mechanism, etc. may be mentioned. Further, as the drive source thereof, various actuators such as an air cylinder and an electric cylinder can be adopted. These matters are subject to claim 3, contract.
It also corresponds to Requirement 4 .

According to a third aspect of the present invention, an etching tank filled with an etching solution , a rotating means for rotating a semiconductor wafer in the etching tank, and a rotating semiconductor wafer are arranged in a rotation axis direction of the wafer. Wafer oscillating means for oscillating in a horizontal direction and a vertical direction in a plane perpendicular to the rotation axis, and a horizontal direction in a plane perpendicular to the rotation axis of the wafer with respect to a rotating semiconductor wafer. Side blowing means for blowing the etching solution from the semiconductor wafer, a uniform blowing means for blowing the etching solution to the rotating semiconductor wafer from substantially the entire area of the bottom surface of the etching tank, and bubbling arranged below the semiconductor wafer. It is an etching apparatus for a semiconductor wafer, which is provided with a bubbler tube for use and a swinging means for the bubbler tube.

According to a fourth aspect of the present invention , an etching tank filled with an etching solution, a rotating means for rotating a semiconductor wafer in the etching tank, and a rotating semiconductor wafer are arranged in a rotation axis direction of the wafer. Wafer oscillating means for oscillating in a horizontal direction and a vertical direction in a plane perpendicular to the rotation axis, and a horizontal direction in a plane perpendicular to the rotation axis of the wafer with respect to a rotating semiconductor wafer. Side blowing means for blowing out the etching solution from the above, and a facing part blowing means for blowing the etching solution into the tank from the vicinity of the part facing the semiconductor wafer in the bottom surface of the etching tank, and for bubbling arranged below the semiconductor wafer. Is a semiconductor wafer etching apparatus provided with the bubbler tube and the bubbler tube swinging means.

[0021]

[Action]

[0022]

[0023]

[0024]

[0025]

According to the first and third aspects of the present invention, while rotating the semiconductor wafer, at the same time, the rotation axis direction of the wafer, the left-right direction and the up-down direction in a plane perpendicular to the rotation axis. Rock to. As a result, for example, a large stirring action occurs between the wafer and the etchant in the wafer magazine containing a plurality of semiconductor wafers. Moreover, during this swinging, the etching solution is blown out from the left and right direction and / or the tilt direction in the plane perpendicular to the rotation axis of the semiconductor wafer, and the etching solution is blown out substantially evenly from almost the entire bottom surface of the etching tank. As a result, in the wafer magazine, the etchant flows laterally between the wafers in a laminar flow state, and moreover, the etching solution is blown out substantially uniformly from almost the entire bottom surface of the etching tank. As a result, the degree of etching of the semiconductor wafers housed in the respective portions becomes substantially equal in the central portion and both end portions of the wafer magazine. At the same time, below the semiconductor wafer, the semiconductor wafer is etched while rocking a bubbler tube that blows out a gas for bubbling. As a result, the effect of etching is enhanced as compared with the case of simply etching while bubbling the semiconductor wafer. From the above, it is possible to manufacture a semiconductor wafer having a higher flatness and a more uniform surface condition.

According to the second and fourth aspects of the present invention, while rotating the semiconductor wafer, at the same time, the rotation axis direction of the wafer, the left-right direction and the up-down direction in a plane perpendicular to the rotation axis. Rock to. As a result, for example, a large stirring action occurs between the wafer and the etchant in the wafer magazine containing a plurality of semiconductor wafers. Moreover, during this swinging, the etching solution is blown out from the left-right direction and / or the tilt direction in a plane perpendicular to the rotation axis of the semiconductor wafer, and from the vicinity of the portion facing the semiconductor wafer on the bottom surface of the etching tank,
The etching liquid is blown into the bath.

By doing so, the etchant flows laterally between the wafers in the wafer magazine in a laminar flow state, and the etching solution is blown out from the vicinity of the portion facing the semiconductor wafer.
For example, in the center and both ends of the wafer magazine,
The degree of etching of the semiconductor wafers housed in the respective parts becomes substantially equal. At the same time, below the semiconductor wafer, the semiconductor wafer is etched while rocking a bubbler tube that blows out gas for bubbling. As a result, the effect of etching is enhanced as compared with the case of simply etching while bubbling the semiconductor wafer. From the above, the invention according to claim 1
In comparison, a semiconductor wafer having higher flatness and more uniform surface condition can be manufactured.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION 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 FIG. For convenience of explanation, the X direction is in the horizontal axis direction of the rotation axis of the silicon wafer, the Y direction is in the horizontal direction in the plane perpendicular to the rotation axis, and the Z direction is in the plane perpendicular to the rotation axis. Vertical direction. 1 is a perspective view of a semiconductor wafer etching apparatus according to a first embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes a semiconductor wafer etching apparatus (hereinafter referred to as an etching apparatus 10). The etching apparatus 10 rotates a large number of silicon wafers W immersed in an etching solution in an etching bath 11. This is an apparatus for etching. Etching bath 11
Is a horizontally long tank that is long in the X direction and is made of, for example, vinyl chloride. An acid-based chemical solution is used as the etching solution. A gutter 11 a is provided around the outer edge of the upper end of the etching bath 11 to receive the overflow liquid of the etching liquid. The etching liquid in the gutter 11a is discharged to the outside through a discharge port provided at a predetermined location.

In each of the two sides of the etching bath 11 in the Y direction, there are three upper, lower, middle, and parallel horizontal nozzles 50.
The left and right pairs are assembled. Each nozzle 50 has the same length as the side surface of the etching tank 11 in the Y direction, and the etching liquid blowing holes are formed on the peripheral surface of each nozzle at a constant pitch along the nozzle axis direction. . The etching liquid blown from each nozzle 50 is blown toward the wafer magazine 12 at the center of the etching tank 11. A large number of silicon wafers W are stored in the wafer magazine 12 in an upright state. That is, the blowing holes of the upper nozzle 50 are formed obliquely downward. Further, the blow-out holes of the nozzle 50 in the middle stage are bored right beside. Further, the blowout holes of the lower nozzle 50 are formed obliquely upward.

Each nozzle 50 is connected to a discharge part of an etching solution supply device 51 for supplying an etching solution.
The etching liquid supply device 51 has an external etching liquid storage tank and a pressure pump for supplying the etching liquid in the tank. This apparatus pressure-feeds the etching solution at 10 to 500 liters / minute. The etching liquid fed under pressure from the etching liquid supply device 51 is supplied from the upper, middle and lower nozzles 50 arranged on both sides of the etching tank 11 in the Y direction to the wafer magazine 1 stored in the center of the tank.
It is blown out toward 2. In addition, these nozzles 50
Further, the etching liquid supply device 51 constitutes a side blowing means.

A perforated plate 5 is provided in the lower part of the etching bath 11.
A lower space 11b partitioned by 3 is formed.
The perforated plate 53 is a rectangular plate member, and a large number of small holes are formed in a matrix in the entire plate. By the etching liquid supply device 51 (also serving as a side blowing unit) and the perforated plate 53, a uniform blowing unit that blows the etching liquid onto the rotating silicon wafer W from substantially the entire bottom surface of the etching bath 11. Is configured.
Further, three etching solution supply pipes 54 are arranged at regular intervals on one side plate of the etching tank 11 in the Y direction. These etching liquid supply pipes 54 supply the etching liquid pumped from the etching liquid supply device 51 into the lower space 11b. Furthermore, lower space 1
In 1b, at the end opposite to the etching liquid supply pipe 54 side,
An irregular reflection plate 55 is attached. The diffuse reflector 55 is
It is a bellows-shaped plate material that diffusely reflects the etching liquid blown out from each supply pipe 54 to the entire lower space 11b.

A bubbler tube 56 for bubbling the etching solution is housed below the wafer magazine 12 on the central portion of the perforated plate 53 so as to be swingable in the Y direction. The main body of the bubbler tube 56 extends in the X direction directly above the perforated plate 53. Moreover, a large number of bubbling holes are bored upward on the peripheral surface thereof at a constant pitch in the tube axis direction. On both sides of the main body part, a pair of hook parts 56 whose tip ends are bent in a U shape toward the outside of the tank.
a is connected. Both hook portions 56a are hooked on the upper edges of both side plates of the etching bath 11 in the X direction. In this state, the bubbler tube 56 is slid in the Y direction.

One end of a pair of horizontal rocking operation tubes 56b is fixed to the lower end of each hook 56a outside the tank. The other ends of the two rocking operation tubes 56b are connected to each other by a connecting rod 56c.
A rod of a bubbler tube rocking cylinder (bubbler tube rocking means) 57 is fixed to an intermediate portion of 6c. An air cylinder is used here as the bubbler tube swing cylinder 57. The rod length is 1c.
In m, the rocking speed is 1 to 60 times per minute.
By moving the rod of the bubbler tube swing cylinder 57 in and out, the tube 56 swings in the Y direction via the swing operation tube 56b and the connecting rod 56c. The other ends of both rocking operation tubes 56b are connected to the N ₂ gas supply unit of the N ₂ gas supply device 58. That is, the N ₂ gas supply device 5
The N ₂ gas pressure-fed from 8 is blown out from the bubbling hole of the main body portion of the bubbler pipe 56 via the swing operation pipe 56b and the hook portion 56a.

The wafer magazine 12 is a cylindrical frame-shaped magazine, and its axial direction is oriented in the X direction. The wafer magazine 12 has two end plates 12a separated from each other by a predetermined distance. Both end plates 12a
Are connected by three parallel rotating shafts 12b arranged at equal angles in the circumferential direction. A large number of silicon wafers W are arranged in the internal space of the wafer magazine 12 formed by these three rotating shafts 12b at a constant pitch along the X direction.

The wafer magazine 12 is hung in a horizontal state on a hanging table 13 arranged above the etching bath 11. That is, a pair of support plates 13a is vertically provided below both ends of the suspension table 13,
In between, it is suspended via two rotary shafts 12c extending outward from the center of each end plate 12a. In addition, a gear-type rotary structure (not shown) that rotates the three rotary shafts 12b collectively is attached to one of the rotary shafts 12c. Further, a rotary motor (rotating means) 14 is suspended from the lower surface of one end of the suspension table 13 via a short connecting plate 13b. When the rotary motor 14 is rotated, the rotary shafts 12b rotate in the same direction via the belt-type power transmission system and the rotary structure (not shown). As a result, all the silicon wafers W in the magazine rotate in a fixed direction.

On the hanging table 13, an X-direction swing motor 15 for swinging the wafer magazine 12 in the X direction and a Y-axis swing motor 15 are provided.
A Y-direction swing motor 16 that swings in the direction and a Z-direction swing motor 17 that swings in the Z direction are provided. The swing motors 15 to 17 swing the hanging table 13 in a predetermined direction via a link structure (not shown). The swing width is 1 to 10 cm, and the swing speed is 1 to 1 minute.
60 times. With these swing motors 15 to 17,
Wafer swinging means for swinging the silicon wafer W in the XYZ directions is configured.

Next, the etching apparatus 1 of the first embodiment
A method of etching the silicon wafer W using 0 will be described. As shown in FIG. 1, the etching apparatus 10 of the first embodiment stores and holds a large number of silicon wafers W in a wafer magazine 12 side by side and immerses the wafer magazine 12 in an etching tank 11. And the rotary motor 1
4, the three rotary shafts 12b are rotated at a predetermined speed. As a result, each silicon wafer W is rotated around its axis by the rotating shaft 12b at a predetermined speed.
During this wafer rotation, XYZ direction swing motors 15 to 17
As a result, the hanging table 13 is swung in the XYZ directions. Along with this, the wafer magazine 12 is also XYZ.
Can be swung in the direction. As a result, wafer magazine 1
In 2, a large stirring action occurs between the silicon wafer W and the etchant, and the etching liquid is evenly contacted with the front and back surfaces of the silicon wafer W. That is, the front surface and the back surface of the silicon wafer W are etched by the etching solution even at the holding portion (the wafer outer peripheral portion) by the rotating shaft 12b
Similarly, even in the central portion of the wafer, the entire surface is uniformly exposed to the etching solution and comes into contact therewith. As a result, a silicon wafer W having high flatness and a uniform surface state can be manufactured.

Moreover, during this swinging, a part of the etching liquid pressure-fed from the etching liquid supply device 51 is stored in the central portion of the etching bath 11 through the three pairs of upper, middle, lower nozzles 50. It is blown out toward the magazine 12. As described above, each nozzle 50 has substantially the same length as the side surface of the etching bath 11 in the Y direction, and the blowing holes are formed over the entire length thereof. As a result, the etchant flows into the gap between the silicon wafers W from the side in a laminar flow state in the swinging wafer magazine 12. As a result, the front and back surfaces of the silicon wafer W and the etching liquid are in better contact with each other.

On the other hand, the rest of the etching liquid from the etching liquid supply device 51 is blown into the lower space 11b of the etching tank 11 through the three supply pipes 54. The blown etching liquid is blown up from the small holes on the entire surface of the perforated plate 53 into the upper space in which the wafer magazine 12 is stored, at a substantially average flow rate. As a result, the front and back surfaces of the large number of silicon wafers W stored in the wafer magazine 12 are etched substantially evenly regardless of the storage position of the magazine 12. At this time, a part of the etching solution collides with the diffuse reflection plate 55 on the opposite side of the lower space 11b and is diffusely reflected, and then spreads in every corner of the lower space 11b. As a result, the etching liquid is blown up substantially uniformly from almost the entire area of the perforated plate 53 without accumulating on the opposite side of the lower space 11b. As a result, the contact between the front and back surfaces of the silicon wafer W and the etching solution is further improved.
At the same time, in the lower portion of the wafer magazine 12, N ₂ gas supplied from N ₂ gas supply unit 58, blown up through the bubbler tube 56 to the wafer magazine 12 side,
The silicon wafer W is bubbled. At this time, the bubbler tube 56 is swung in the Y direction by moving the rod of the bubbler tube swing cylinder 57 in and out. As a result, the effect of the etching is enhanced as compared with the case where the silicon wafer W is simply etched while bubbling.

A semiconductor wafer etching method and apparatus according to the second embodiment of the present invention will be described below with reference to FIGS. FIG. 2 is a perspective view of a semiconductor wafer etching apparatus according to a second embodiment of the present invention. 3 to 5 are enlarged plan views of other partition plates.
As shown in FIG. 2, the etching apparatus 30 of the second embodiment.
In contrast, the etching apparatus 10 of the first embodiment swings the silicon wafer W side, while swinging the etching tank 11 side. Further, in the etching apparatus 30 of the second embodiment, a partition plate 31 that blows out the etching solution from a portion facing the silicon wafer W is adopted instead of the porous plate 53 of the first embodiment. Furthermore, lower space 1
The diffuse reflection plate 55 of 1b is omitted. The diffuse reflector 5
5 may be left as it is. The features of the second embodiment will be described below.

In this etching apparatus 30, the XYZ direction swinging motors 15 to 17 of the hanging table 13 are omitted, and instead, the swinging motors 15 to 17 are arranged on the mounting table 32 of the etching tank 11. There is. Also, etching tank 1
A partition plate 31 is provided in the lower portion of the partition 1.
The lower space 11b is defined by 1. At the central portion of the partition plate 31 facing the silicon wafer W, a large blow-up port 31a for blowing the etching solution to the silicon wafer W side is formed. Blowing mouth 31a
Is a rectangular shape that is long in the X direction, and has substantially the same size as the wafer magazine 12 in plan view. These partition plates 31 and etching liquid supply device 51 (also serve as side blowing means)
By the above, a facing part blowing means for blowing the etching solution into the inside of the tank substantially evenly from the part of the bottom surface of the etching tank 11 facing the silicon wafer W is constituted. As shown in FIGS. 3 to 5, in place of the partition plate 31, partition plates 33, 34, and 35 having a horizontally long rectangular blow-up opening 31a and a different-shaped blow-up opening may be adopted. . That is, the partition plate 33 may have a diamond-shaped blow-up port 33a opened near the center of the plate. Further, as shown in FIG. 4, a partition plate 34 may be formed by forming three circular blow-up openings 34a near the center of the plate.
Further, as shown in FIG.
A partition plate 35 may be formed by arranging two a's.

Next, the etching apparatus 3 of the second embodiment
A method of etching the silicon wafer W using 0 will be described. During etching, while the silicon wafer W is being rotated, the etching tank mounting table 32 is rocked in the XYZ directions by the rocking motors 15 to 17. Therefore, the etching bath 11 and the etching liquid in this bath rock in the same direction and undulate. As a result, the same stirring action of the etching liquid as in the first embodiment occurs between the silicon wafers W immersed in the etching liquid, and the contact of the etching liquid on the front and back surfaces of the wafer becomes good.

During this etching, the lower space 1
The etching liquid in 1b is blown up by the blowing port 3 of the partition plate 31.
A relatively large amount is blown up toward the wafer magazine 12 directly above through 1a. At this time, the blow-up port 31
The size a is substantially the same as the wafer magazine 12. As a result, the etching liquid can be sprayed from below between the stored silicon wafers W regardless of the part of the wafer magazine 12. Moreover, at the time of this spraying, the bubbling by the bubbler tube 56 is accompanied by the same action as in the first embodiment. Therefore, due to the synergistic effect with the bubbling, the contact of the etching liquid on the front and back surfaces of the wafer is further improved, and the silicon wafer W having higher flatness and more uniform surface condition is obtained.

As described above, even if the etching bath 11 is swung, a silicon wafer W having a high flatness and a uniform surface state can be produced as in the first embodiment. Moreover, since the partition plate 31 is adopted instead of the porous plate 53 of the first embodiment, the etching liquid blown up from the bottom surface side of the bath is concentrated immediately below the silicon wafer W. Therefore, in the wafer magazine 12, the etching liquid flows between the silicon wafers W from below in a laminar flow state. As a result, the contact of the etching liquid on the front and back surfaces of the wafer can be further improved as compared with the first embodiment. Other configurations, operations, and effects are the same as those in the first embodiment, so description thereof will be omitted.

[0047]

【The invention's effect】

[0048]

[0049]

[0050]

[0051]

According to the inventions of claims 1 and 3,
Then, during etching, while rotating the wafer, at the same time, the wafer is rocked back and forth, left and right, and up and down.
Evenly blown up the etchant from the entire bottom surface of the etching bath, it further since so as to swing the bubbler tube under the semiconductor wafer, a higher flatness, moreover the more surface states to produce a homogeneous semiconductor wafers it can.

[0053] According to the invention of mounting the serial to claims 2 and 4, during the etching, while rotating the semiconductor wafer, the wafer back and forth, is swung in the horizontal direction and the vertical direction, moreover the semiconductor wafer , The etching solution is blown up from the side and the lower area facing the wafer, and the bubbler tube is swung below the semiconductor wafer. Therefore, compared with the invention according to claim 1,
A semiconductor wafer having higher flatness and more uniform surface condition can be manufactured.

[Brief description of drawings]

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

FIG. 2 is a perspective view of a semiconductor wafer etching apparatus according to a second embodiment of the present invention.

FIG. 3 is an enlarged plan view of another partition plate.

FIG. 4 is an enlarged plan view of another partition plate.

FIG. 5 is an enlarged plan view of another partition plate.

[Explanation of symbols]

10, 30 Semiconductor Wafer Etching Device, 11 Etching Tank, 14 Rotation Motor (Rotating Means), 15 X-direction Oscillation Motor (wafer Oscillation Means), 16 Y-direction Oscillation Motor (wafer Oscillation Means), 17 Z-direction Swing motor (wafer swing means), 31, 33, 34, 35 Partition plate (opposite part blowing means), 31a, 33a, 34a, 35a blow outlets, 50 nozzles (side blow means), 51 Etching liquid supply device (Side blowing means, uniform blowing means, facing part blowing means), 53 perforated plate (uniform blowing means), 56 bubbler tube, 57 bubbler tube swing cylinder (bubbler tube swinging means), W silicon wafer (semiconductor wafer) .

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-9-74082 (JP, A) JP-A-5-109689 (JP, A) JP-A-9-17757 (JP, A) JP-A-10- 74727 (JP, A) Actual Kaihei 7-7140 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21 / 306,21 / 308

Claims (4)

(57) [Claims] 1. A method for etching a semiconductor wafer in which a semiconductor wafer immersed in an etching solution in an etching bath is rotated to perform etching, wherein the semiconductor wafer is rotated while the direction of the rotation axis of the wafer is simultaneously adjusted. And oscillate horizontally in a vertical plane and vertically, and the etching solution is spouted from the horizontal direction in a plane perpendicular to the axis of rotation of the wafer, and is evenly distributed from almost the entire bottom surface of the etching tank. A method for etching a semiconductor wafer, in which an etching solution is blown up onto the wafer and bubbling is performed while rocking a bubbler tube disposed below the semiconductor wafer. 2. A method for etching a semiconductor wafer in which a semiconductor wafer immersed in an etching solution in an etching bath is rotated to perform etching, wherein the semiconductor wafer is rotated while the direction of the rotation axis of the wafer and the rotation axis of the wafer are simultaneously measured. With respect to the horizontal and vertical directions in a plane vertical to, and the etching solution is blown from the horizontal direction in a plane perpendicular to the rotation axis of this wafer, and further with the semiconductor wafer on the bottom of the etching tank. A method for etching a semiconductor wafer, in which an etching solution is blown up from the vicinity of a facing portion and bubbling is performed while rocking a bubbler tube arranged below the semiconductor wafer. 3. An etching tank filled with an etching solution, a rotating means for rotating a semiconductor wafer in the etching tank, and a rotating semiconductor wafer in a rotation axis direction of the wafer and perpendicular to the rotation axis. Wafer oscillating means for oscillating in the horizontal and vertical directions in a horizontal plane, and to the side of the rotating semiconductor wafer to blow out the etching solution from the horizontal direction in the plane perpendicular to the rotation axis of the wafer. A blowing means, a uniform blowing means that blows the etching liquid to the rotating semiconductor wafer substantially uniformly from the substantially entire bottom surface of the etching tank, and a bubbler tube for bubbling arranged below the semiconductor wafer. A semiconductor wafer etching apparatus comprising a bubbler tube swinging means. 4. An etching tank filled with an etching solution, a rotating means for rotating a semiconductor wafer in the etching tank, and a rotating semiconductor wafer in a rotation axis direction of the wafer and perpendicular to the rotation axis. Wafer oscillating means for oscillating in the horizontal and vertical directions in a horizontal plane, and to the side of the rotating semiconductor wafer to blow out the etching solution from the horizontal direction in the plane perpendicular to the rotation axis of the wafer. A blowing means, a facing portion blowing means for blowing an etching solution into the bath from the vicinity of a portion facing the semiconductor wafer in the bottom surface of the etching bath, a bubbler tube for bubbling arranged below the semiconductor wafer, and the bubbler. An apparatus for etching a semiconductor wafer, comprising a tube swinging means.