TW579552B - Two-piece design filtrating bath - Google Patents

Abstract

A two-piece design filtrating bath is consisted of an outer bath, an inner bath, a loader plate, an acid suction member and a fixation member. The inner bath set in the outer bath at least comprises a plurality of support pins set in the inner bath for adjusting the height difference between inner bath and outer bath and an acid suction member fixation opening set in the base of inner bath. The loader plate is set in the inner bath for loading the cassette. The acid suction member is fixed on the acid suction member fixation opening with a flexible pipe, and forming an acid suction channel. A fixation member is set between loader plate and inner bath for fixing loader plate and the inner bath.

Description

579552 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a semiconductor process equipment, and more particularly to a two-piece circulating tank. [Prior Art] Wet etching is the earliest etching technique used. It uses the chemical reaction between the film and a specific solution to remove the film that is not covered by photoresist. The advantages are simple process, low etching cost, high throughput and high reliability. Due to residues of by-products and particles when removing the film, the life of #etching solution is short when using a single tank circulation tank, so in order to extend the service life of the etching solution The number of particles increases). Wet stations used in the semiconductor industry usually use wet etching circulation tanks with internal and external groove structures. Such wet etching circulation grooves with internal and external groove structures are pumped by pumps. The etching solution in the outer tank is supplied to the filter after being pressurized by a pump to filter out by-products, particles and other residues in the etching solution, and then the clean etching fluid is returned to the inner tank. The excess etching solution in the inner tank will flow into the outer tank in an overflow manner to form a circulation system. FIG. 1 is a cross-sectional view showing the structure of a conventional wet etching circulation tank. As shown in Fig. 1, the wet etching circulation tank 100 includes at least an inner tank 102, an outer tank 104, a loader plate 106, a pipeline 1 08, a pump 1 1 0, a pipe It is composed of circuit 1 1 2, filter 1 1 4 and pipeline 1 1 6. Wherein, the cassette holder 106 is arranged in the inner tank 102; the outer tank 104 is connected to the inlet end of the pump 110 through the pipeline 108; the outlet end of the pump 110 is connected via

9694twf.ptd Page 8 579552 V. Description of the invention (2) The pipeline 112 is connected to the inlet end of the filter 114; the outlet end of the filter 114 is connected to the bottom of the inner tank 102 through the pipeline 1 1 8. During the operation, the etching solution is first supplied to the inner tank 102 and the outer tank 104, and then the pump 1 1 0 is used to extract the etching liquid in the outer tank 10 to the inlet end of the pump 1 110. After being pressurized by the pump 1 10, it is supplied to the filter 1 1 4 and the etching liquid is filtered by the filter 1 1 4 and then the etching hydraulic pressure is returned to the inner tank 10 2. Since the inner tank 102 is a space for immersing the product (for example, a wafer), and the height of the liquid level in the inner tank 102 is lower than that in the outer tank 104, the excess remaining liquid will flow into the outside in an overflow manner. The grooves 104 are formed into a circulation system, which can repeatedly filter the etching solution and ensure the cleanness of the etching solution. Then, during the wet etching process, the wafer cassette 1 2 0 in which the wafer Π 8 is placed is further set on the wafer cassette holder 104 in the inner groove 102 to make the wafer 110 immerse in The etching is performed in the etching solution in the tank 102, and after a fixed time of etching, the wafer cassette is transferred to the next chemical station. In the above-mentioned wet etching cycle tank, the material of the inner tank 102 and the outer tank 104 is quartz, and the inner tank 102 and the outer tank 104 are usually sintered by welding. However, the processing of quartz needs to be processed in an extremely high temperature environment, and the more complicated the structure of the processed part, the more likely the stress generated after cooling at high temperature will cause the structure to crack. Moreover, since the combination of the inner groove 102 and the outer groove 104 and the space and depth of the two groove walls are limited by welding, the design is complicated and the production cost is high. In addition, in the conventional wet etching cycle tank, a liquid level detector and an acid drain pipe are usually required in the inner and outer tanks, which makes the pipeline and control circuit of the wet etching cycle tank complicated. [Inventive Content]

9694twf. Ptd Page 9 ^ / 9552 579552 V. Description of the invention (4) The acid absorption head member at the bottom of the tank is provided with an opening to form the second acid absorption pipe for the inner tank and the outer tank mound. The inner tube of the acid head and the outer head are formed. The inner tube of the acid absorption head keeps a fixed diameter from a first end until the diameter is gradually enlarged when it approaches a second end. The second end of Shuo Neiguan protrudes a predetermined distance from the inner tube of the acid absorption head, and the portion of the outer tube of the acid absorption head protruding from the inner tube of the acid absorption head has a notch. The fixing member is disposed between the cassette holder and the inner slot, and is used for fixing the cassette holder and the inner slot. The internal diameter of the outer tube of the acid absorption head of the ten-head suction head member is larger than the outer diameter of the second end of the inner tube of the acid absorption head. Therefore, there is a gap between the inner tube of the acid absorption head and the outer tube of the acid absorption head. The inner tube of the acid absorption head and the outer tube of the acid absorption head are welded together at an interval / setting angle. One end of the flexible pipe fitting covers the acid-absorbing head member setting port, and the other end of the flexible pipe fitting covers the acid-absorbing head outer member Ϊ Ϊ I 2 The engraving liquid will pass through the acid-absorbing head member setting port and the acid-absorbing head. The gap between the structure and the η gap between the inner tube of the acid absorption head and the outer tube of the acid absorption head is iced to the bottom of the acid absorption head member, and is drawn from the acid absorption tube through the inside of the acid absorption head member. from. The inner groove and the outer groove of the notch soil f 1 at the bottom of the piece are set separately in the middle of the evening, by adjusting the support column: In the state where the outer groove is installed in the field groove, the inner groove is level to make the erosion ^ ^ Robotic arms and products, and the flow from the overflow to the outer tank is uniform, and the production set is covered evenly, which can improve the product processing quality. Two-j oblique leads to the aggregation of particles, separation of the grooves, and separation of the outer grooves 9694twi.ptd 579552 5. Description of the invention (5) Design, so there is no restriction on the minimum welding size between the inner and outer grooves, the groove width can be reduced, and the total width of the entire machine It can be smaller than the conventional machine. Moreover, the inner tank and the outer tank are connected by an acid-absorbing head member, so only a set of liquid level detectors are needed to achieve the functions of both liquid level monitoring and circulation system startup signal monitoring, thus simplifying the two-piece Design of piping and control circuit of the circulating tank. In addition, a flexible sleeve is used to assemble the acid absorption head member at the bottom of the inner tank to form an inner tank and an outer tank sharing the same acid absorption pipe, ensuring that only one suction device (A spirat 〇) can be used to complete the acid drainage operation. , And can simplify the design of the acid drainage pipeline of the two-piece circulation tank. In addition, the inner wall of the inner tank is provided with a plurality of support bumps. These support bumps can cooperate with the fixing member to fix the cassette holder in the inner tank, thereby ensuring the accuracy of the cassette transfer. In addition, the inner and outer grooves, the inner groove and the crystal circle E seat are supported and positioned by elastic members, so the assembled two-piece circulation groove has better impact resistance. In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below in conjunction with the accompanying drawings to describe in detail as follows: [Embodiment] Figures 2A to 2 Figure C is a top view, a perspective view in the X direction, and a perspective view in the Y direction of the two-piece circulation tank according to the preferred embodiment of the present invention. Please refer to FIG. 2A to FIG. 2C. The two-piece circulating tank 2 0 of the present invention includes at least an inner tank 3 0 0, an outer tank 4 0 0, a wafer E seat 5 0 0, and an acid absorption head. Component 6 0 0 and fixed component 7 0 0.

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/ Slot 3 0 0 is set in the outer slot 4 0 to receive the etching solution, = wet etching reaction, and the height of the inner slot 3 0 0 is higher than outside. ", The seat 5 0 0 is set in the inner slot 300 Θ, Used to carry fixed wafers. : The component 600 is assembled on the bottom side of the inner groove 300 with a flexible member, and the acid absorption pipe shared by the groove 300 and the outer groove 400. The fixing member 7〇〇 is fixed in the inner groove 300 by the cassette holder 500. '' Next, the inner tank 300, the outer tank 400, the wafer tray holder 500, the acid absorption head member 600, and the fixed member 700 of the two-piece circulating tank 200 of the present invention will be described. structure. Please refer to FIG. 3A to FIG. 3C, which are respectively a top view and an X-direction perspective view of the inner groove of the two-piece circulation tank of the preferred embodiment of the present invention. The inner groove 300 includes at least the inner groove body 3 02, the four supporting pillars a and grooves 3 04, the communication hole 3 06, the acid-absorbing head member setting opening 3 08, the four support projections 310, And support pillar 312 and other components. The inner groove body 3 0 2 can be distinguished into, for example, an inner groove body upper portion 3 002 a and an inner groove body lower portion 302 b. The width of the inner groove body upper portion 302 a is, for example, larger than the width of the inner groove body lower portion 302 b. The X-direction perspective view of O2 has a T-shaped cross section, for example. The four support column setting grooves 3 0 4 are respectively provided at four corners below the bottom of the inner tank body 302, and the support column setting grooves 3 04 are, for example, hollow cylindrical, so the support column 3丨 2 is disposed in the supporting column setting groove 304. Moreover, when the inner groove 300 is set in the outer groove 400 (as shown in FIG. 2A to FIG. 2C), the inner groove 3 0 0 and the outer groove 4 0 0 can be adjusted by adjusting the height of the support post 3 12. Height difference between

9694twf.ptd Page 13 579552 V. Description of the invention (7) Under the condition that the robot arm and the outer tank need to be changed, ensure that the inner tank is at a level of 3 0 0 so that the etching solution evenly covers the product and overflow to the outer tank 4 The flow direction is uniform, and the particles will not be agglomerated due to deflection. The communication hole 3 0 6 is, for example, provided on one side of the bottom of the inner groove body 3 0 2 and is used to communicate with the inner groove 3 0 when the inner groove 300 is provided in the outer groove 400 (as shown in FIGS. 2A to 2C). 0 and outer slot 4 0 0. The acid-absorbing head member installation port 3 0 8 is, for example, provided at a corner of the inner tank body 3 202 for setting the acid-absorbing head member 600 (as shown in FIGS. 2A to 2C). The four supporting bumps 3 1 0 are, for example, disposed on the inner wall of the inner groove body 3 0 2. These supporting bumps 310 can cooperate with the fixing member 700 (as shown in FIG. 2A to FIG. 2C) to mount the cassette holder 5 0 0 It is fixed in the inner slot 300 to ensure the accuracy of wafer cassette transfer. The material of the support post 3 1 2 is, for example, an elastic material, and the support post 3 1 2 is, for example, provided in the support post setting groove 304 to support the inner groove body 3 0 2 〇 The support post setting groove of the inner groove 300 described above 304 and support bumps 310 are described by taking four as an example. Of course, it is also possible to set less than four or more than four support pillars to set grooves 3 04 and support bumps 310 as required. 〇 Please refer to 4A to 4C are respectively a top view, a perspective view in the X direction, and a perspective view in the γ direction of a two-part circulating groove according to a preferred embodiment of the present invention. The outer groove 400 includes at least an outer groove body 402, a foot base 404, and a grip 406. The outer tank body 4 02 is, for example, box-shaped, and is used to receive the inner tank 300. foot

9694twf. Ptd Page 14 579552 V. Description of the invention (8) The seat 4 0 4 is, for example, provided at the four corners of the outer groove body 4 02 to support the outer groove body 402. The grip 406 is, for example, provided on the outer wall of the upper part of the outer groove body 402, and the operator can lift the outer groove body 402 by using the grip 406. Please refer to FIG. 5A to FIG. 5C for a top view, a perspective view in the X direction, and a perspective view in the Y direction of the wafer cassette holder of the two-piece circulation tank of the preferred embodiment of the present invention, respectively. The cassette holder 500 includes at least a cassette holder body 502, a cassette fixing pin 504, and a positioning pin 506. The cassette holder body 502 is, for example, a quartz grid. The wafer cassette fixing bolt 502 is, for example, provided on the cassette base body 502 to fix the cassette. The positioning bolt 5 0 6 is disposed on the side of the cassette holder body. A flexible sleeve can be sleeved on the positioning bolt 5 06, and then the positioning bolt 506 of the flexible sleeve can be fixed with the fixing member 70. 0 (as shown in FIG. 2A to FIG. 2C), and cooperate with the supporting protrusion 310 (shown in FIGS. 3A to 3C) provided in the inner groove 300 to place the cassette holder 5 0 0 It is fixed in the inner slot 300 to ensure the accuracy of wafer cassette transfer. Please refer to FIGS. 6A to 6C to illustrate the top view, cross-sectional view, and bottom view of the acid absorption head member of the two-piece circulating tank of the preferred embodiment of the present invention. The acid-absorbing head member 600 includes at least the acid-absorbing head inner tube 602 and the acid-absorbing head outer tube 604. One end 6 0 2 a of the acid absorption head inner tube 6 0 2 is, for example, a hollow cylinder, and the other end 6 0 2 b of the acid absorption head inner tube 6 0 2 is, for example, a truncated hollow circle.

The tapered shape, that is, the inner tube 6 02 of the acid absorption head maintains a fixed diameter from one end 6 0 2 a, and the diameter gradually increases when it approaches the other end 6 0 2 b. The acid-absorbing head outer tube 6 0 4 is, for example, provided at the other end 6 0 2 b of the acid-absorbing head inner tube 6 0 2 and protrudes from the acid-absorbing head inner tube 6 0 2 —a predetermined distance, and the acid-absorbing head outer tube 6 0 4 burst

9694twf. Ptd Page 15 579552 V. Description of the invention (9) A part of the inner tube 6 0 2 of the acid suction head is formed with a notch 6 0 8 (for example, shown in cross section) in the cross section. The inner diameter of the outer tube 604 of the acid absorption head is larger than the outer diameter of the other end 602b of the inner tube 602 of the acid absorption head, so there is a gap between the inner tube 6 0 2 of the acid absorption head and the outer tube 6 0 4 of the acid absorption head. . In addition, the inner tube of the acid absorption head 6 0 2 and the outer tube of the acid absorption head 6 0 4 are welded together at every Θ degree angle, where the 0 degree angle is, for example, 120 degrees, so the inner tube 6 of the acid absorption head Between 0 2 and the outer tube 6 0 4 of the acid absorption head, for example, there is a welding point 6 0 6 at every 120 degree angle. Next, please refer to the schematic diagram of the assembly of the acid absorption head member between the inner tank and the outer tank as shown in FIG. 7. The components of FIG. 7 are the same as those of FIGS. 3A to 3C, FIGS. 4A to 4C, and FIGS. 6A to 6C, and the description is omitted. First, one end of the acid absorption head member 600 (that is, the end 602a of the acid absorption head inner tube 602) is inserted into the acid absorption head member setting port Mg of the inner tank 300. Then, the flexible cannula 800 was used to cover the acid-absorbing head member setting port 3 08 and the acid-absorbing head member 600, and the acid-absorbing head outer tube 604, and the acid-absorbing head member 600. The other end (ie, the end 602b of the inner tube 602 of the acid absorption head) contacts the bottom of the outer groove 400. Next, at the end of one of the acid absorption head members 600, the end 6G2a of the inner tube 602 is connected to the acid absorption tube 802, and the setting of the absorption member 600 is completed. 1 Ji Zhan and a text head structured person explained the action of the acid absorption head member 600. Extract the etching solution through the acid absorption tube 802, the inner two are not shown.) The mouth 308 and the acid absorption head are provided by the acid absorption head member ^ The remaining liquid will pass through the gap between the inner tube 602 of the head and the outer tube m of the acid absorption head, the bottom of the acid absorption member 6 0 0, and pass through the gap of the acid absorption head structure to the inside of the acid absorption head σ卩 while pumping from acid tube 8 0 2

579552 V. Description of the invention (10) The remaining liquid in the outer groove 4 0 〇 is combined ☆ A concave n WQ π 丄 -j is formed by the bottom of the acid absorption head member 6 0 〇 ^^ The inside of the head member was evacuated from the acid suction tube 802. Due to the bottom line, Kaixin, t L casing 8 0 0 assembled the acid absorption head member 6 0 0 in the inner tank 300 2; = ν (Α outer tank 4 0 0 shared the same acid absorption pipe, indeed, π # π mf out (A rat〇r) can complete the acid drainage operation, and start the signal monitoring system to achieve both liquid level monitoring and circulation system = 8 The picture shows the two pieces of the preferred embodiment of the present invention The structure of the loop member of the type circulation groove is not intended. The fixing member 700 is, for example, a hollow cylinder, and the material is, for example, an elastic material. On the circumferential side wall of the fixing member 700, a positioning pin insertion hole 7202 and one The slot portion 704. The slot portion 704 is connected to the chin plug insertion hole 702. That is, Fig. 9 is a diagram showing the fixing of the fixing member according to the preferred embodiment of the present invention. Schematic diagram of the structure of the inner groove. The components in Figure 9 are the same as those in Figures M to = 6, 6A to 6C, and 8 and the descriptions are omitted. The cassette holder is omitted. The positioning bolt 506 of 5000 can be inserted into the flexible sleeve 900, and then inserted into the positioning bolt insertion hole 700 of the fixing member 700, and the top of the fixing member 700 abuts against The support bump 310 of the inner groove 300 is provided with a positioning inspection 506 on the sides of the wafer cassette holder 500, and the inner wall of the inner groove 300 is also provided with a corresponding wafer] The position of the positioning bolt Mg of the 500 seat Supporting the bump 310, so the cassette holder 500 can be fixed in the inner groove 300 by a fixing member. In addition, since the material of the fixing member 700 is an elastic material, the assembled structure will have better resistance Impact.

9694twf. Ptd

579552 5. Description of the invention (11) According to the embodiment, the inner groove and the outer groove of the present invention are designed separately. When the inner groove is set in the outer groove, the inner can be adjusted by adjusting the height of the support column. The height difference between the groove and the outer groove can ensure the level of the inner groove and evenly cover the product without the need to change the robot arm and the outer groove, and the flow direction of the overflow to the outer groove is uniform. Deflection leads to agglomeration of particles, which can improve product processing quality. Because the inner and outer grooves are designed separately, there is no restriction on the minimum welding size between the inner and outer grooves. The groove width can be reduced, so that the total width of the entire machine can be smaller than the conventional machine. Moreover, the inner tank and the outer tank are connected by an acid-absorbing head member, so only a set of liquid level detectors are needed to achieve the functions of both liquid level monitoring and circulation system startup signal monitoring, thus simplifying the two-piece Design of piping and control circuit of the circulating tank. In addition, a flexible sleeve is used to assemble the acid absorption head member at the bottom of the inner tank to form an inner tank and an outer tank sharing the same acid absorption pipe, ensuring that only one suction device (A spirat 〇) can be used to complete the acid drainage operation. , And can simplify the design of the acid drainage pipeline of the two-piece circulation tank. In addition, the inner wall of the inner tank is provided with a plurality of support bumps. These support bumps can cooperate with the fixing member to fix the cassette holder in the inner tank, thereby ensuring the accuracy of the cassette transfer. In addition, the inner and outer grooves, the inner groove and the wafer box holder are supported and positioned by elastic members, so the assembled two-piece circulation groove has better impact resistance. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Anyone skilled in the art will not depart from the present invention.

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9694twf. Ptd Page 19 579552 Brief Description of the Drawings Figure 1 is a cross-sectional view showing a conventional wet etching cycle tank; Figures 2A to 2C are drawings respectively illustrating the preferred embodiment of the present invention Top view, X-direction perspective view, and Y-direction perspective view of the two-piece circulation tank; FIGS. 3A to 3C are top views of the inner grooves of the two-piece circulation tank of the preferred embodiment of the present invention, respectively. Views, X-direction perspective views and Y-direction perspective views; Figures 4A to 4C are top views, X-direction perspective views, and X-direction perspective views of the two-part circulation tank outside the preferred embodiment of the present invention, respectively; Y perspective view; FIGS. 5A to 5C are a top view, a X direction perspective view, and a Y direction perspective view, respectively, of a cassette holder of a two-piece circulating tank according to a preferred embodiment of the present invention; 6A to 6C are respectively an upper view, a sectional view, and a lower view of the acid-absorbing head member of the two-piece circulation tank of the preferred embodiment of the present invention; FIG. 7 is a view illustrating the present invention. Schematic diagram of the assembly of the acid absorption head member of the two-piece circulating tank of the preferred embodiment between the inner tank and the outer tank; FIG. 8 is a drawing A schematic view of two-part fixing member of the preferred embodiment of the invention, the circulation groove; and a graph illustrates the structure of the ninth preferred embodiment of the present invention fixing member fixing the crystal and the inner circle pocket groove of FIG. The description of the symbols of the drawings: 1 0 0: wet etching circulation tank 1 0 2, 3 0 0: inner tank 1 0 4, 4 0 0: outer tank ·

9694twfl.ptd Page 20 579552 Simple description of the drawings 106 108 110 114 118 120 200 302 3 0 2 a 3 0 2b 3 0 4: 3 0 6: 3 0 8: 310: 312: 4 0 2: 4 0 4: 4 0 6: 5 0 2: 5 0 4: 5 0 6: 6 0 2: 6 0 2 a 6 0 4: 5 0 0: cassette holder 1 1 2, 1 1 6 ·· line pump

Filter wafer Wafer S Two-piece circulation tank Inner tank body: Inner tank body Upper part: Inner tank body Lower support post Set groove communication hole Acid absorption head member set mouth support bump Support post Outer tank body Foot grip Cassette holder body Wafer cassette fixing bolt positioning bolt Acid absorption head inner tube, 60 2 b: End acid absorption head outer tube

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Claims (1)

579552 VI. Scope of patent application 1. A two-piece circulating trough comprising: an outer trough; an inner trough arranged in the outer trough, the inner trough including at least: a plurality of supports Pillars, the support pillars are arranged at the bottom of the inner groove to adjust the height difference between the inner groove and the outer groove; a plurality of support protrusions, the support protrusions are arranged on the inner wall of the inner groove; and an acid absorption head A component installation opening is provided at the bottom of the inner groove; a wafer cassette base is arranged in the inner groove to carry a plurality of wafer cassettes, and the wafer cassette seat includes at least a plurality of positioning bolts An acid absorption head member, the acid absorption head member is provided with a flexible pipe at the acid absorption head member setting opening at the bottom of the inner tank, and constitutes an acid absorption pipe shared by the inner tank and the outer tank; and A fixing member is disposed between the wafer cassette base and the inner groove, and is used for fixing the wafer cassette base and the inner groove. 2. The two-piece circulation tank according to item 1 of the patent application scope, wherein the acid absorption head member includes: an acid absorption head inner tube, the acid absorption head inner tube maintains a fixed diameter from a first end The diameter of the tube is gradually enlarged until approaching a second end; and an acid suction head outer tube, the acid suction head outer tube is arranged on the acid suction head inner tube 9694twf. Ptd Page 23 579552 6. The second end of the scope of patent application, which protrudes a predetermined distance from the inner tube of the acid suction head, and the part of the outer tube of the acid suction head protruding from the inner tube of the acid suction head has a notch. 3. The two-piece circulation tank according to item 2 of the scope of the patent application, wherein the inner diameter of the outer tube of the acid absorption head is larger than the outer diameter of the second end of the inner tube of the acid absorption head. 4. The two-piece circulation tank according to item 3 of the scope of the patent application, wherein there is a gap between the inner tube of the acid absorption head and the outer tube of the acid absorption head, and the inner tube of the acid absorption head and the acid absorption head The outer tubes are welded together at every set angle. 5. The two-piece circulation tank according to item 3 of the scope of the patent application, wherein one end of the flexible pipe fitting is sleeved on the acid absorption head member setting port, and one end of the flexible pipe fitting is sleeved on the acid absorption head Outer tube. 6. The two-piece circulation tank according to item 1 of the scope of the patent application, wherein the material of the support columns is an elastic material. 7. The two-piece circulating groove according to item 1 of the scope of patent application, wherein the fixing member includes a positioning bolt insertion hole and a slot portion. 8. The two-piece circulation tank according to item 1 of the scope of patent application, wherein the material of the fixing member is an elastic material. 9. The two-piece circulating groove according to item 1 of the scope of patent application, wherein each of the positioning bolts of the cassette holder is sleeved with a flexible pipe and inserted into the positioning bolt insertion hole of the fixing member, and The top of the fixing member abuts each of the supporting protrusions of the inner groove. 10. The two-piece circulation tank according to item 1 of the scope of the patent application, further comprising an acid absorption tube, the acid absorption tube being disposed on the acid absorption head member. 9694twf. Ptd Page 24 579552 6. Scope of patent application The first end, and the etching solution in the inner tank and the outer tank can be discharged from the acid absorption tube through the acid absorption head member. 1 1. A two-piece circulation groove, the double-piece circulation groove comprises: an outer groove; an inner groove, the inner groove is arranged in the outer groove, and the inner groove includes at least: a plurality of supporting protrusions, the A support bump is provided on the inner wall of the inner tank; and an acid suction head member setting opening is provided at the bottom of the inner tank; a wafer cassette holder is disposed in the inner groove for carrying a plurality of A wafer cassette, the wafer cassette base including at least a plurality of positioning bolts; an acid absorption head member, the acid absorption head member is provided with a flexible pipe at the bottom of the inner tank, and the acid absorption head member is provided at an opening; The inner tank and the outer tank share an acid absorption pipe, and the acid absorption head member includes: an acid absorption head inner tube, the acid absorption head inner tube maintains a fixed diameter from a first end to a second end The tube diameter gradually increases; and an acid suction head outer tube, the acid suction head outer tube is disposed at the second end of the acid suction head inner tube, and protrudes a predetermined distance from the acid suction head inner tube, the acid absorption The part of the outer tube of the head protruding from the inner tube of the acid absorption head has a recess 9694twf. Ptd page 25 579552 6. Application scope of the patent; and a fixing member, the fixing member is disposed between the cassette holder and the inner slot to fix the cassette holder and the inner slot. 1 2. The two-piece circulation tank according to item 11 of the scope of patent application, wherein the inner diameter of the outer tube of the acid absorption head is larger than the outer diameter of the second end of the inner tube of the acid absorption head. 1 3. The two-piece circulation tank according to item 11 of the scope of patent application, wherein there is a gap between the inner tube of the acid absorption head and the outer tube of the acid absorption head, and the inner tube of the acid absorption head and the suction tube The acid-tipped outer tubes are welded together at every other set angle. 1 4. The two-piece circulation tank according to item 11 of the scope of patent application, wherein one end of the flexible pipe is sleeved on the acid suction head member setting opening, and one end of the flexible pipe is sleeved on the suction Sour head outer tube. 1 5. The two-piece circulating groove according to item 11 of the scope of patent application, wherein the fixing member includes a positioning bolt insertion hole and a slot portion. 16. The two-piece circulation tank according to item 11 of the scope of patent application, wherein the material of the fixing member is an elastic material. 1 7. The two-piece circulating groove according to item 11 of the scope of patent application, wherein each of the positioning bolts of the cassette holder is sleeved with a flexible pipe and inserted into the positioning inspection insertion hole of the fixing member. 'And the top of the fixing member abuts each of the supporting bumps of the inner groove. 1 8. The two-piece circulation tank according to item 11 of the scope of patent application, further comprising an acid suction tube, the acid suction tube is disposed at the first end of the acid suction head member, and the inner tank and the The etching solution in the outer tank can be passed through the suction 9694twf.ptd p. 26 579552 9694twf. Ptd Page 27