Baffle plate used during wet etching
By designing a baffle containing anti-backsplash and recycling structure, the problem of etching liquid splashing in the wet etching device is solved, and the effect of reducing backsplash and improving product yield is achieved.
Patent Information
- Application Number
- CN202421440148.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-21
- Publication Date
- 2025-04-22
- Estimated Expiration
- 2034-06-21
AI Technical Summary
In the existing wet etching device, the etching liquid is prone to splashing, resulting in defects on the wafer surface and affecting product yield.
A baffle is designed including a anti-splash structure and a recovery structure, and the etching liquid thrown from the wafer is reduced and recovered through a combination of vertical plates, horizontal reduction plates, shields and peripheral inclined plates to avoid backsplash.
It effectively reduces the splash and backsplash of the etching liquid, avoids defects on the wafer surface, and improves the product yield.
Smart Images
Figure CN222785265U_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of semiconductor equipment manufacturing, in particular to a baffle used in wet etching. Background Art
[0002] Figure 1 A schematic structural diagram of an existing single-wafer wet etching device is shown, which includes a wafer carrier 10 with a rotating function, a plurality of clamps 20 arranged on the wafer carrier 10, an etching liquid spraying device 30 with two nozzles 31 and an arm 32, and a baffle 40 arranged on the periphery of the wafer carrier 10, and different baffles are required for different etching liquids. Figure 1 The baffles (first baffle 40a and second baffle 40b) corresponding to the two different etching solutions are shown. The functions of the baffles include: preventing the chemical solution, i.e., the etching solution, from splashing around, blocking the etching solution and recovering it, such as achieving acid discharge, alkali discharge, and organic liquid discharge.
[0003] However, Figure 1 The baffle shown cannot avoid splashing. The first baffle 40a and the second baffle 40b have the same structure, both consisting of a vertical plate, and an extension section extending inwardly, ie, one side of the wafer, is disposed at the top of the vertical plate. Figure 1 The dotted arrow line in the figure represents the movement trajectory of the etching liquid thrown out from the wafer. It can be seen that the etching liquid with a higher speed will collide with the baffle. Since the etching liquid has a higher incident speed, the speed after the collision will be very large, and finally backsplashing will occur as shown by the dotted arrow line. The etching liquid corresponding to the dotted arrow line will finally return to the surface of the wafer, thereby etching the surface of the wafer, thereby forming defects, and finally affecting the yield of the product.
[0004] Existing improved methods for reducing etching solution splashing include: 1) increasing the distance between the baffle and the wafer; 2) using a fan filter unit (FFU) to reduce splashing. Summary of the invention
[0005] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a baffle used in wet etching to solve the problem of splashing of the prior etching solution.
[0006] To achieve the above-mentioned purpose and other related purposes, the present invention provides a baffle plate used in wet etching, the baffle plate is placed on the periphery of a wafer, and comprises: an anti-splashback structure for decelerating the etching liquid thrown out of the wafer,
[0007] The anti-splash structure comprises:
[0008] A first vertical plate, which is disposed on one side of the wafer and is placed vertically with a distance between the first vertical plate and the wafer, and has a first extension portion extending toward the wafer at the top thereof;
[0009] A vertical opening passes through the first vertical plate, and the vertical opening is arranged on a movement track of the etching liquid thrown out from the surface of the wafer, so that the etching liquid passes through the vertical opening;
[0010] A horizontal deceleration plate, the horizontal deceleration plate is fixedly arranged on a side of the first vertical plate away from the wafer and located below the vertical opening;
[0011] A shielding plate, the shielding plate is a zigzag structure with an angle less than 180°, which is fixedly arranged on a side of the first vertical plate away from the wafer and located above the vertical opening, and the lowest end of the shielding plate is located above the horizontal speed brake;
[0012] A second vertical plate, which is disposed on a side of the shielding plate away from the wafer and is placed vertically with a spacing therebetween, and has a second extension portion extending toward the shielding plate at its top end;
[0013] The peripheral inclined plate is arranged above the shielding plate, a first end of which is fixedly connected to the first extension portion of the first vertical plate, and a second end of which is fixedly connected to the second extension portion.
[0014] Optionally, the shielding plate includes an upper inclined plate and a lower inclined plate, one end of the upper inclined plate is fixedly connected to the first vertical plate, and the other end thereof is fixedly connected to the lower inclined plate, and the end of the lower inclined plate is the lowest end of the shielding plate, and its position in the horizontal direction exceeds the end of the horizontal speed brake.
[0015] Optionally, the horizontal speed brake is made of porous rough material.
[0016] Optionally, the baffle further includes a recovery structure for collecting the etching liquid, and the recovery structure includes:
[0017] At least two horizontal openings are arranged at intervals through the horizontal deceleration plate, and the etching liquid decelerated by the horizontal deceleration plate passes through the horizontal openings and flows downward to be recovered.
[0018] Optionally, there are multiple baffles.
[0019] Optionally, at least two spaced-apart vertical openings are provided on the first vertical plate of some of the baffles, and each of the vertical openings is provided with a corresponding anti-splashback structure and the recovery structure. In this case, the first vertical plate can move up and down.
[0020] Optionally, the length of the second vertical plate is greater than the length of the first vertical plate.
[0021] Optionally, the etching solution includes an acid solution, an alkaline solution and an organic liquid.
[0022] Optionally, the second vertical plate and the outer inclined plate are made of porous materials, which can adsorb and recover the etching liquid.
[0023] As described above, the baffle used in the wet etching of the present invention introduces the solution with kinetic energy thrown from the wafer into the baffle provided by the present invention, and uses different methods to slow down the solution, thereby reducing splashing; and uses the surface-treated porous and open design (horizontal opening) to recover the etching solution; the baffle provided by the present invention can prevent the area with a width of 1 cm to 3 cm on the edge of the wafer from being splashed back by the etching solution, thereby avoiding the splashed etching solution from forming defects on the wafer, thereby improving the product yield. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a schematic structural diagram of a conventional single-wafer wet etching device with a baffle.
[0025] Figure 2 Shown is a schematic diagram of the baffle structure of the present invention.
[0026] Description of Reference Numerals
[0027] 40, 100: baffle; 40a: first baffle; 40b: second baffle; 110: first vertical plate; 111: first extension; 112: vertical opening; 120: horizontal deceleration plate; 121: horizontal opening; 130: shielding plate; 131: upper inclined plate; 132: lower inclined plate; 140: second vertical plate; 141: second extension; 150: peripheral inclined plate; 200: wafer; 10, 300: wafer carrier; 20, 400: fixture; 500: etching liquid injection device; 31, 510: nozzle; 510a: first nozzle; 520: second nozzle; 520: arm; 600: etching liquid delivery pipeline DETAILED DESCRIPTION
[0028] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.
[0029] See also Figure 1 to Figure 2It should be noted that the illustrations provided in this embodiment are only schematic illustrations of the basic concept of the present invention. Although the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation, the form, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the component layout may also be more complicated.
[0030] like Figure 2 As shown, this embodiment provides a baffle 100 used in wet etching, the baffle 100 is placed on the periphery of the wafer 200, and includes: an anti-splashback structure for decelerating the etching liquid thrown out of the wafer 200,
[0031] The anti-splash structure comprises:
[0032] A first vertical plate 110, which is disposed on one side of the wafer 200 and is placed vertically with a distance between the first vertical plate 110 and the wafer 200, and has a first extension portion 111 extending toward the wafer 200 at its top;
[0033] A vertical opening 112 passes through the first vertical plate 110 , and the vertical opening 112 is arranged on a movement track of the etching liquid thrown out from the surface of the wafer 200 , so that the etching liquid passes through the vertical opening 112 ;
[0034] A horizontal deceleration plate 120, wherein the horizontal deceleration plate 120 is fixedly disposed on a side of the first vertical plate 110 away from the wafer 200 and is located below the vertical opening 112;
[0035] The shielding plate 130 is a zigzag structure with an angle less than 180°, which is fixedly disposed on a side of the first vertical plate 110 away from the wafer 200 and located above the vertical opening 112, and the lowest end of the shielding plate 130 is located above the horizontal speed reducer 120;
[0036] A second vertical plate 140, which is disposed on a side of the shielding plate 130 away from the wafer 200 and is placed vertically with a gap between the second vertical plate 140 and the shielding plate 130, and has a second extension portion 141 extending toward the shielding plate 130 at its top;
[0037] The outer inclined plate 150 is disposed above the shielding plate 130 , a first end of which is fixedly connected to the first extension portion 111 of the first vertical plate 110 , and a second end of which is fixedly connected to the second extension portion 141 .
[0038] In this embodiment, the baffle 100 is a part of a single-chip wet etching device, and the single-chip wet etching device also includes a wafer carrier 300, a clamp 400, and an etching liquid injection device 500. The wafer carrier 300 is used to place the wafer 200 and rotate the wafer 200. The clamp 400 is arranged on the wafer carrier 300, and the clamp 400 fixes the wafer 200 by clamping the edge of the wafer 200. The etching liquid injection device 500 includes a nozzle 510 and an arm 520. The nozzle 510 includes a first nozzle 510a and a second nozzle 510b, which respectively spray different etching liquids. The nozzle 510 is arranged on the arm 520 and is connected to the etching liquid delivery pipeline 600. In this embodiment, the dotted arrow line 701 represents the movement trajectory of the etching liquid thrown out from the surface of the wafer 200; the dotted arrow line 702 represents the path of the etching liquid flowing on the surface of the horizontal speed reducer 120; the dotted arrow line 703 and the arrow 704 represent the path of the etching liquid flowing from the surface of the horizontal speed reducer 120 to the second vertical plate 140 and the outer inclined plate 150.
[0039] Specifically, the etching solution includes an acid solution, an alkaline solution and an organic liquid.
[0040] Specifically, the horizontal speed reducer 120 is made of porous rough material.
[0041] Specifically, the shielding plate 130 includes an upper inclined plate 131 and a lower inclined plate 132, one end of the upper inclined plate 131 is fixedly connected to the first vertical plate 110, and the other end thereof is fixedly connected to the lower inclined plate 132, and the end of the lower inclined plate 132 is the lowest end of the shielding plate 130, and its position exceeds the end of the horizontal speed reducer 120 in the horizontal direction.
[0042] In this embodiment, the end of the lower inclined plate 132 of the shielding plate 130 exceeds the end of the horizontal deceleration plate 120 in the horizontal direction (the end of the horizontal deceleration plate 120 is the end of the horizontal deceleration plate 120 away from the first vertical plate 110), so that the etching liquid dripping from the shielding plate 130 can be dripped and recovered. Moreover, in this embodiment, the porous and rough horizontal deceleration plate 120 can make the etching liquid lose kinetic energy and decelerate.
[0043] Specifically, the length of the second vertical plate 140 is greater than the length of the first vertical plate 110 .
[0044] Specifically, the second vertical plate 140 and the outer inclined plate 150 are made of porous materials, which can adsorb and recover the etching solution.
[0045] Specifically, the baffle further includes a recovery structure for collecting the etching liquid, and the recovery structure includes:
[0046] At least two horizontal openings 121 spaced apart from each other are provided through the horizontal deceleration plate 120 , and the etching liquid decelerated by the horizontal deceleration plate 120 passes through the horizontal openings and flows downward to be recovered.
[0047] In this embodiment, a recovery bucket is placed below the dotted arrow 705 , and the etching liquid flows downward along the dotted arrow line 705 into the recovery bucket.
[0048] In this embodiment, the number of the horizontal openings is 2.
[0049] Specifically, there are a plurality of baffles. In this embodiment, each of the baffles can recover at least one type of etching solution.
[0050] Specifically, at least two vertical openings 112 are arranged at intervals on the first vertical plate 110 of some of the baffles, and each vertical opening 112 is provided with a corresponding anti-splashback structure and the recovery structure. At this time, the first vertical plate 110 can move up and down.
[0051] In this embodiment, when the vertical opening 112 moves to a position on the motion track of the etching liquid thrown out by the wafer 200, the anti-splash structure and the recovery structure corresponding to the vertical opening 112 are used to recover the etching liquid. Moreover, in this embodiment, the first vertical plate 110 capable of moving up and down is provided with two vertical openings 112, namely an upper vertical opening 112a and a lower vertical opening 112b. Figure 2 The horizontal speed brake 120, the shielding plate 130, the second vertical plate 140 and the peripheral inclined plate 150 are the same as those in the baffle shown on the right. Figure 2 The horizontal speed reducer 120, the shielding plate 130, the second vertical plate 140 and the peripheral inclined plate 150 are the same as those in the baffle shown on the right. When the acid solution needs to be recovered, the position of the upper vertical opening 112a is moved to the movement track of the etching solution thrown out of the wafer 200; when the alkaline solution needs to be recovered, the position of the lower vertical opening 112b is moved to the movement track of the etching solution thrown out of the wafer 200.
[0052] In summary, the baffle used in wet etching of the present invention introduces the solution with kinetic energy thrown from the wafer into the baffle provided by the present invention, and uses different methods to slow down the solution, thereby reducing the occurrence of splashing; and uses the surface-treated porous and open design (horizontal opening) to recover the etching solution; the baffle provided by the present invention can prevent the 1cm to 3cm width area of the wafer edge from being splashed by the etching solution, thereby avoiding the splashed etching solution from forming defects on the wafer, thereby improving the product yield. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.
[0053] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.
Claims
1. A baffle used in wet etching, characterized in that: The baffle is placed on the periphery of the wafer and includes: an anti-splashing structure for decelerating the etching liquid thrown out of the wafer, The anti-splash structure comprises: A first vertical plate, which is disposed on one side of the wafer and is placed vertically with a distance between the first vertical plate and the wafer, and has a first extension portion extending toward the wafer at the top thereof; A vertical opening passes through the first vertical plate, and the vertical opening is arranged on a movement track of the etching liquid thrown out from the surface of the wafer, so that the etching liquid passes through the vertical opening; A horizontal deceleration plate, the horizontal deceleration plate is fixedly arranged on a side of the first vertical plate away from the wafer and located below the vertical opening; A shielding plate, the shielding plate is a zigzag structure with an angle less than 180°, which is fixedly arranged on a side of the first vertical plate away from the wafer and located above the vertical opening, and the lowest end of the shielding plate is located above the horizontal speed brake; A second vertical plate, which is disposed on a side of the shielding plate away from the wafer and is placed vertically with a spacing therebetween, and has a second extension portion extending toward the shielding plate at its top end; The peripheral inclined plate is arranged above the shielding plate, a first end of which is fixedly connected to the first extension portion of the first vertical plate, and a second end of which is fixedly connected to the second extension portion.
2. The baffle used in wet etching according to claim 1, characterized in that: The shielding plate includes an upper inclined plate and a lower inclined plate, one end of the upper inclined plate is fixedly connected to the first vertical plate, and the other end thereof is fixedly connected to the lower inclined plate, and the end of the lower inclined plate is the lowest end of the shielding plate, and its position exceeds the end of the horizontal speed brake in the horizontal direction.
3. The baffle used in wet etching according to claim 1 or 2, characterized in that: The horizontal speed reducer is made of porous rough material.
4. The baffle used in wet etching according to claim 3, characterized in that: The baffle further includes a recovery structure for collecting the etching liquid, and the recovery structure includes: At least two horizontal openings are arranged at intervals through the horizontal deceleration plate, and the etching liquid decelerated by the horizontal deceleration plate passes through the horizontal openings and flows downward to be recovered.
5. The baffle used in wet etching according to claim 4, characterized in that: The number of the baffles is multiple.
6. The baffle used in wet etching according to claim 5, characterized in that: At least two vertical openings arranged at intervals are arranged on the first vertical plate of some of the baffles, and each vertical opening is provided with a corresponding anti-splashback structure and the recovery structure. At this time, the first vertical plate can move up and down.
7. The baffle used in wet etching according to claim 1, characterized in that: The length of the second vertical plate is greater than the length of the first vertical plate.
8. The baffle used in wet etching according to claim 1, characterized in that: Etching solutions include acid solutions, alkaline solutions and organic liquids.
9. The baffle used in wet etching according to claim 1, characterized in that: The second vertical plate and the outer inclined plate are made of porous materials and can absorb and recover the etching liquid.