JP2004335669A - Etching equipment - Google Patents

Abstract

An object of the present invention is to eliminate unevenness in etching an ingot.
In an apparatus for performing an etching process by immersing an ingot in an etching solution tank, a basket for mounting the ingot having an arcuate surface on at least a part of an outer surface is provided, and an upper surface of a bottom wall of the basket is provided. A concave arc surface on which the arc surface of the ingot 16 is placed is provided, the basket 15 is immersed in the etching solution tank 17, and the basket 15 is rocked by the rocking means 14 to roll the ingot 16.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an etching apparatus, and more particularly to an etching apparatus that uniformly etches an ingot having an arcuate surface on at least a part of its outer surface.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a process of manufacturing a compound semiconductor such as gallium arsenide (GaAs), an etching process is performed to remove impurities such as an oxide film on an ingot surface and obtain a crystal surface. Japanese Patent Application Laid-Open No. Hei 4-26124 discloses a method for etching the surface of an ingot without unevenness. Specifically, as shown in FIG. Ingots 3 are stacked and etched with a large number of spheres 4 made of glass or Teflon (R) interposed therebetween.
[0003]
In addition, as shown in FIG. 8, in Japanese Patent Application Laid-Open No. 9-75874, the single crystal block 5 is fixed to the support member 7 via the carbon bed 8 and is suspended in the washing liquid tank 6 while being suspended. At the same time, low-frequency ultrasonic waves and high-frequency ultrasonic waves are simultaneously applied by the ultrasonic wave applying mechanisms 9A and 9B provided on the bottom wall and the side wall of the cleaning liquid tank 6, and the oil and abrasive particles attached to the single crystal block 5 are removed. Desorption / elimination.
[0004]
[Patent Document 1]
JP-A-4-26124 [0005]
[Patent Document 2]
JP-A-9-75874
[Problems to be solved by the invention]
However, according to the etching method shown in FIG. 7, there is a problem that unevenness occurs in the etching, because there is a portion of the ingot 3 that is always in contact with the sphere 4 during the etching process. Further, since the ingot 3 and the sphere 4 are merely stacked and placed in the etching container 1, the etching solution 2 is not stirred and the etching solution 2 near the surface of the ingot 3 is not easily replaced. In addition, there is a problem that the concentration of the etching solution 2 tends to be non-uniform.
[0007]
Also in the apparatus shown in FIG. 8, the single crystal block 5 is hung by the support member 7 and the carbon bed 8, and a portion of the single crystal block 5 is always in contact with the carbon bed 8. There is a problem that unevenness is generated in the etching, and labor for fixing the single crystal block 5 to the support member 7 is required, and the number of operations is increased. Further, when the weight of the single crystal block 5 is large, there is a problem that the structure of the support member 7 becomes large and the power thereof is also required to increase the cost of the apparatus.
[0008]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to eliminate unevenness in etching an ingot without increasing the number of operations and the power of a device.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides an apparatus for performing an etching process by immersing an ingot in an etching solution tank,
At least a part of the outer surface is provided with a basket on which an ingot having an arc surface is mounted, and a concave arc surface on which the arc surface of the ingot is mounted is provided on the bottom wall of the car, and the basket is placed in the etching solution tank. The present invention provides an etching apparatus characterized in that the basket is immersed and the basket is rocked by a rocking means to roll the ingot.
[0010]
With the above configuration, the arc surface of the ingot is placed on the cage bottom wall which is a concave arc surface, so that the ingot can be rolled on the car by rocking the basket by the rocking means. it can. Therefore, a portion where the ingot and the car come into contact with each other is changed in a state where the ingot placed on the car is immersed in the etching liquid tank, and it is possible to eliminate unevenness of etching of the ingot. Further, since the basket is oscillated while being immersed in the etching liquid tank, the etching liquid is agitated and the concentration is made uniform, so that the unevenness of etching can be further reduced. Further, since the worker only needs to place the ingot on the basket, the work of fixing the ingot to the supporting member as in the related art is unnecessary, and the working efficiency can be improved.
[0011]
In an apparatus for performing an etching process by immersing an ingot in an etching liquid tank, a basket for mounting an ingot having an arc surface on at least a part of an outer surface is provided, and an arc surface is provided on a lower surface of a bottom wall of the car, and the arc of the ingot is provided. The basket on which the surface is placed is immersed in the etching solution tank, and the arc surface of the lower surface of the bottom wall of the basket is brought into contact with the bottom surface of the etching solution tank or the upper surface side of the horizontal plane provided in the etching solution tank. An etching apparatus is provided in which the basket is rolled and rocked on the bottom surface or the horizontal plane by a rocking means in a state of being in contact with the cage, thereby rolling the ingot.
[0012]
With the above configuration, the lower surface of the bottom wall, which is the arc surface of the basket, is rolled and rocked by the rocking means while being placed on the bottom surface of the etching liquid tank or on a horizontal surface provided in the etching liquid tank. Therefore, the ingot on the basket can be rolled. Therefore, the contact portion between the ingot and the basket changes, and the etchant is also stirred, so that unevenness in etching of the ingot can be eliminated.
Moreover, since the bottom wall of the basket is placed on the bottom surface of the etching solution tank or on the horizontal surface in the solution tank to receive the weight of the ingot, the load on the basket and the swinging means can be reduced, and the weight is large. It is possible to deal with even ingots. Further, since the weight of the ingot is not directly applied to the car, the driving force of the rocking means and the like can be reduced, which contributes to a reduction in the cost of the apparatus.
[0013]
A horizontal actuator for transporting the basket in a horizontal direction,
A vertical actuator for vertically moving the basket,
Control means for controlling the horizontal actuator and the vertical actuator,
The horizontal actuator and the vertical actuator transport the basket on which the ingot is placed into and out of the etching solution tank, and control the time during which the basket is immersed in the etching solution tank.
[0014]
With the above configuration, the time for immersing the basket on which the ingot is placed in the etching solution tank can be made constant by the control means, so that the etching quality of the ingot can be kept constant. Conventionally, the basket was supported manually, so burns due to the splashing of the chemical solution and fatigue due to heavy handling work were large, but according to the present invention, these problems can be solved by automating the transport of the basket. .
[0015]
The swing means is attached to a tip end of a swing pneumatic cylinder fixed to the guide frame in a horizontal direction and a rod portion extending in a horizontal direction from the swing pneumatic cylinder. A slider slidably mounted on the slider, and a hook provided below the slider,
With the basket suspended from the hook, the basket is rocked by reciprocating the rocking pneumatic cylinder, and the rod can be stopped at three positions so that the basket is tilted to the left. , And can be stopped at three positions: a neutral position and a right tilt position.
[0016]
With this configuration, the slider can slide and slide on the guide frame by simply moving the pneumatic cylinder in the horizontal direction, and the basket suspended from the hook can be easily swung. In addition, since the basket can be given a play by being hooked and hung on the hook portion, the movement of the basket is not hindered when the basket is rolled by contacting the bottom surface of the etching solution tank.
[0017]
In addition, since the car can be stopped at three positions, that is, a left tilt position, a neutral state, and a right tilt position, when the ingot is transported in a state of being placed on the car, the ingot is balanced by setting the neutral state. In addition to preventing falling from the basket due to collapse, when immersing in the etching solution tank and swinging, the ingot is rolled over a wide range by making a reciprocating stroke from the neutral state to the left tilt position and right tilt position It is possible to further reduce the unevenness of the etching.
[0018]
When the number of times of swinging and the swinging speed of the car are controlled to predetermined values by the control means for controlling the swinging means, the etching quality of the ingot can be kept constant.
[0019]
It is preferable that irregularities or grooves are provided on the upper surface of the bottom wall of the car, or that the bottom wall of the car is made in a saw-tooth or net-like shape.
That is, by making the bottom wall of the basket into the above shape, the ingot can be supported at multiple points, and there is an advantage that the etching liquid can easily enter the ingot surface. Also, it is necessary to prevent foreign matter, etc., which has been detached from the ingot, from falling into the concave portion or the groove, or dropping through a gap in a shape of a saw or a net, and preventing the foreign matter from intervening on the contact surface between the basket and the ingot. Is also possible.
[0020]
It is preferable that the cage, the horizontal actuator, the vertical actuator and / or the oscillating means are made of a corrosion-resistant resin.
With the above configuration, corrosion of the basket, the horizontal actuator, the vertical actuator, and the oscillating means due to the vapor of the etching solution or the like is preferably prevented. Specific examples of the corrosion-resistant resin include hard vinyl chloride, polypropylene, and a fluorine-based resin, which provide good corrosion resistance to aqua regia (a mixture of concentrated hydrochloric acid and concentrated nitric acid) used as an etchant. Can be obtained.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
FIGS. 1 and 2 show the process of manufacturing a compound semiconductor such as gallium arsenide (GaAs) or indium phosphide (InP) used in a wide range of fields such as a semiconductor laser, a light emitting diode, and a mobile communication device. An etching apparatus 10 for removing an adhered oxide film and foreign matter.
[0022]
The etching apparatus 10 is provided with a horizontal frame 21 which crosses in the horizontal direction above a frame 11 forming a frame, and a vertical actuator 13 is attached to the horizontal frame 21 via a horizontal actuator 12. The horizontal actuator 12 slide-fits a sliding portion 23 provided on a lower surface of a projecting piece 24 projecting laterally from an upper portion of the vertical actuator 13 to a guide rail 22 provided on an upper surface of a horizontal frame 21, and a pneumatic cylinder. The slide rail 25 slides on the guide rail 22. In addition, stoppers 33 made of urethane or the like are arranged on both sides of the guide rail 22.
[0023]
The vertical actuator 13 includes a pneumatic cylinder, and has a lower end connected horizontally to a guide frame 27 via a turning part 26. The guide frame 27 has an upper surface as a slide surface and a mounting wall 28 projecting upward. As shown in FIG. 3, the swinging pneumatic cylinder 14 constituting the swinging means is fixed to the mounting wall 28 by a fixing portion 34.
The horizontal actuator 12 and the vertical actuator 13 are controlled by control means (not shown), and control the transport time, transport speed, immersion time, and the like of the basket 15.
[0024]
The oscillating pneumatic cylinder 14 has a first piston 29 and a second piston 30 fitted inside a cylindrical casing 33 via a seal member 37, and a distal end opening of which is sealed by an annular closing portion 35 with a seal member 38. Is closed through.
The casing 33 is provided with a first port 33a, a second port 33b, and a third port 33c, which serve as compressed air supply holes. As shown in FIG. A stopper 36 that separates the first piston 29 and the second piston 30 from the surface protrudes.
The first piston 29 includes a cylindrical sliding contact portion 29a and a rod-shaped pressing portion 29b protruding from the sliding contact portion 29a. The second piston 30 has a cylindrical sliding contact portion 30a, a long rod portion 30b protruding from the sliding contact portion 30a, and a pressing portion 29b of the first piston 29 that is formed by drilling the end surface of the sliding contact portion 30a. And a recess 30c to be fitted inside. Note that a seal member 39 is interposed at a contact portion between the rod portion 30b and the closing portion 35. The swinging pneumatic cylinder 14 is controlled by control means (not shown) to control the swinging time and swinging speed of the cage 15.
[0025]
A slider 31 is provided on the upper surface on the distal end side of the guide frame 27, and is connected to the distal end of the rod portion 30b of the second piston 30 by a bearing portion 31b, and for hanging the basket 15 below the slider 31. The hook part 31a is hung integrally.
As shown in FIGS. 2 and 3, the basket 15 is provided on a bottom wall 15a which is a concave arc surface, both side walls 15b, a shaft portion 15d connecting the upper portions of the both side walls 15b, and an upper surface of the bottom wall 15a. The bottom wall 15a has a groove 15c, a low side wall 15e protruding from both ends of the bottom wall 15a, and a drainage hole 15f formed in the bottom wall 15a.
[0026]
The etching solution tank 17 storing the etching solution 19 is disposed in the outer tank 18 storing the hot water 20, and these are installed on the installation table 32. The hot water is transferred at a temperature of 20 ° C. to 50 ° C. via the outer wall of the etching solution tank 17 to maintain the etching solution 19 at a predetermined temperature. As the etching solution 19, aqua regia (a mixture of concentrated hydrochloric acid and concentrated nitric acid) is used.
[0027]
The horizontal actuator 12, the vertical actuator 13, the oscillating pneumatic cylinder 14, the cage 15, the guide frame 27, the slider 31 and the like are made of corrosion-resistant resin to prevent corrosion of the etching solution 19 due to vapor or the like. In addition, as the corrosion-resistant resin, hard vinyl chloride, polypropylene, fluorine resin, or the like is used.
In order to further increase the strength, the metal may be formed by molding with a corrosion resistant resin, or may be formed with FRP (glass fiber reinforced plastic) or the like.
Further, the seal member 37 attached to the outer periphery of the first and second pistons 29 and 30 and slidably in contact with the casing 33 is made of a rubber O-ring covered with DLC (diamond like carbon), and is made of resin. The occurrence of sliding contact noise is prevented by eliminating the chemical affinity with the casing 33 made of. Note that a normal O-ring, packing, or the like may be used.
[0028]
Next, the operating principle of the swinging pneumatic cylinder 14 will be described with reference to FIGS.
The rod portion 30b extending from the oscillating pneumatic cylinder 14 adjusts the pressure of the air supplied to the first port 33a, the second port 33b, and the third port 33c so that the forward position, the neutral position, and the reverse position are adjusted. And stop at three positions.
Specifically, assuming that the air pressure supplied to the first port 33a is P1, the air pressure supplied to the second port 33b is P2, and the air pressure supplied to the third port 33c is P3, when P1>P3> P2, As shown in FIG. 6A, the first piston 29 moves forward until it comes into contact with the stopper 36, and the second piston 30 stops at the position where the tip of the pressing portion 29b comes into contact with the bottom of the concave portion. The rod portion 30b is in the neutral position.
When P1>P2> P3, as shown in FIG. 6B, the second piston 30 moves forward until it comes into contact with the closing portion 35, and the rod portion 30b is at the forward position. When P3> P2 = P1 = 0, as shown in FIG. 6C, the first piston 29 moves backward until it contacts the left end, and the second piston 30 moves backward until it contacts the stopper 36. , The rod portion 30b is in the reverse position.
[0029]
Next, an etching process using the etching apparatus 10 will be described.
As shown in FIG. 3, a column-shaped ingot 16 is placed on the bottom wall 15a of the basket 15 with the swinging pneumatic cylinder 14 at the neutral position, and the horizontal actuator 14 and the vertical actuator 13 are controlled by the control means. The basket 15 is moved to the position just above the etching solution tank 17 by controlling.
[0030]
Then, the basket 15 is lowered by the vertical actuator 13 to be immersed in the etching solution 19, and the bottom wall 15 a of the basket 15 is placed on the bottom surface 17 a of the etching solution tank 17. Thus, the weight of the ingot 16 is received by the bottom surface 17a of the etching solution tank 17, and the load applied to the hook portion 31a by the shaft portion 15d of the cage 15 can be reduced.
From this state, as shown in FIG. 4, the slider 31 slides on the upper surface of the guide frame 27 by moving the rod portion 30b to the forward position by the swinging pneumatic cylinder 14 controlled by the control means (not shown). The basket 15 is rolled on the bottom surface 17a of the etching solution tank 17 via the shaft portion 15d hooked on the hook portion 31a, swings to the right tilt position, and the ingot 16 rolls on the basket 15 Move.
[0031]
Also, as shown in FIG. 5, the rod portion 30b is moved to the reverse position by the swinging pneumatic cylinder 14, whereby the slider 31 slides on the upper surface of the guide frame 27 and moves backward, and the shaft portion hooked on the hook portion 31a. The basket 15 is rolled on the bottom surface 17a of the etching solution tank 17 via 15d, swings to the left inclined position, and the ingot 16 rolls on the basket 15.
[0032]
With the above configuration, the ingot 16 immersed in the etching solution tank 17 can be rolled on the basket 15 by swinging the basket 15 by the swing pneumatic cylinder 14. Therefore, the contact portion between the ingot 16 and the basket 15 changes, and the etching solution 19 is agitated to make the concentration uniform, thereby making it possible to eliminate the unevenness of the etching of the ingot 16. Further, since the operator only needs to place the ingot 16 on the basket 15, it is not necessary to fix the ingot 16 to the support member as in the related art, and the working efficiency can be improved.
Moreover, since the bottom wall 15a of the basket 15 is swung while being placed on the bottom surface 17a of the etching solution tank 17, the weight of the ingot 16 is not directly loaded on the basket 15, so that the swing pneumatic cylinder 14 and the like The driving force can be reduced, and the cost of the apparatus can be reduced.
[0033]
Further, since the control means controls the time for immersing the basket 15 on which the ingot 16 is placed in the etching solution tank 17 and the number of times and the speed of the swing of the basket 15 to predetermined values, the etching of the ingot 16 is controlled. Quality can be kept constant. Conventionally, since the basket was supported manually, there were many burns due to the scattering of the chemical solution and fatigue due to heavy handling work. However, according to the present invention, these problems can be solved by automatically transporting the basket 15.
[0034]
Furthermore, since the groove 15c is provided on the upper surface of the bottom wall 15a of the cage 15, the ingot 16 can be supported at multiple points, and there is an advantage that the etching liquid 19 can easily enter the surface of the ingot 16. . In addition, it is possible to prevent foreign matter powder and the like detached from the ingot 16 from falling into the groove 15c and from intervening on the contact surface between the basket 15 and the ingot 16.
In addition, unevenness may be provided in place of the groove 15c, or the bottom wall of the cage may be shaped like a saw blade or a net, and foreign matter separated from the ingot 16 may be passed through the gap and dropped into the etching solution tank 17. You may.
[0035]
【The invention's effect】
As is apparent from the above description, according to the present invention, the basket is rocked by placing the arc surface of the ingot on the cage bottom wall which is a concave arc surface, and the ingot is rolled on the basket. As a result, the portion where the ingot contacts the basket can be changed, and the concentration of the etchant can be uniformed by stirring the etchant, so that it is possible to eliminate unevenness in the etching of the ingot. Further, since the worker only needs to place the ingot on the basket, the work such as fixing the ingot to the supporting member as in the related art is unnecessary, and the working efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a front view of an etching apparatus according to an embodiment of the present invention.
FIG. 2 is a side view of the etching apparatus.
FIG. 3 is a front view before a basket is immersed in an etching solution tank.
FIG. 4 is a front view of a state of swinging to a right tilt position.
FIG. 5 is a front view of a state where the rocker has swung to a left tilt position.
FIGS. 6A to 6C are mechanism diagrams of a swinging pneumatic cylinder.
FIG. 7 is a drawing showing a conventional example.
FIG. 8 is a drawing showing another conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Etching apparatus 12 Horizontal actuator 13 Vertical actuator 14 Pneumatic cylinder 15 for rocking 15 Basket 15a Bottom wall 15c Groove 15d Shaft 16 Ingot 17 Etching solution tank 17a Bottom surface 18 Outer tank 19 Etching solution 20 Hot water 27 Guide frame 29 First piston 30 First 2 piston 30b rod 31 slider 31a hook 31b bearing

Claims (6)

In an apparatus for immersing an ingot in an etching solution tank and performing an etching process,
At least a part of the outer surface is provided with a basket on which an ingot having an arc surface is mounted, and a concave arc surface on which the arc surface of the ingot is mounted is provided on the bottom wall of the car, and the basket is placed in the etching solution tank. An etching apparatus characterized in that the basket is immersed and the basket is rocked by a rocking means to roll the ingot. In an apparatus for immersing an ingot in an etching solution tank and performing an etching process,
At least a part of the outer surface is provided with a cage on which an ingot having an arc surface is mounted, an arc surface is provided on the lower surface of the bottom wall of the cage, and the basket on which the arc surface of the ingot is placed is immersed in the etching solution tank. At the same time, in a state in which the arc surface of the lower surface of the bottom wall of the cage is in contact with the bottom surface of the etching solution tank or the upper surface side of the horizontal surface provided in the etching solution tank, the cage is swung by the rocking means. An etching apparatus, characterized in that the etching apparatus is configured to roll on the horizontal plane and swing to rotate the ingot. A horizontal actuator for transporting the basket in a horizontal direction,
A vertical actuator for vertically moving the basket,
Control means for controlling the horizontal actuator and the vertical actuator,
The horizontal actuator and the vertical actuator convey the car on which the ingot is placed into and out of the etching solution tank, and controls a time during which the car is immersed in the etching solution tank. The etching apparatus according to claim 1. The swing means is attached to a tip end of a swing pneumatic cylinder fixed to the guide frame in a horizontal direction and a rod portion extending in a horizontal direction from the swing pneumatic cylinder. A slider slidably mounted on the slider, and a hook portion provided below the slider,
With the basket suspended from the hooks, the basket is rocked by reciprocating the rocking pneumatic cylinder. The etching apparatus according to any one of claims 1 to 3, wherein the etching apparatus can be stopped at three positions: a neutral position and a right tilt position. The etching apparatus according to any one of claims 1 to 4, wherein irregularities or grooves are provided on the upper surface of the bottom wall of the car, or the bottom wall of the car is made in a saw-tooth shape or a net shape. The etching apparatus according to any one of claims 1 to 5, wherein the cage, the horizontal actuator, the vertical actuator, and / or the oscillating means are made of a corrosion-resistant resin.

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