Wafer wet etching apparatus and etching method

Abstract

The embodiment of the application discloses a wafer wet etching device and an etching method. The wafer wet etching device comprises a barrel body, a driving assembly and a bearing assembly. The bearing assembly comprises a plurality of vertical columns, and a clamping groove is formed on each vertical column. Based on the wafer wet etching device provided by the embodiment of the application, the wafer can be clamped on the plurality of vertical columns through the clamping groove in the use process, and then the bearing assembly together with the wafer is placed in the barrel body. The etching liquid in the barrel body is driven to flow by the driving assembly, and the etching liquid can etch the wafer by wet etching. The embodiment of the application drives the etching liquid to flow by the driving assembly, instead of the traditional manual rotation of the wafer. On the one hand, the controllable etching liquid flow rate can improve the wet etching efficiency. On the other hand, the consistency and uniformity of the wet etching can be guaranteed.

Description

Technical Field

[0001] This application relates to the field of semiconductor chip manufacturing technology, and in particular to a wafer wet etching apparatus and etching method. Background Technology

[0002] With the development of the semiconductor industry and the pursuit of high performance and reliability, there are often differences in materials and structures, leading to higher design and process requirements. Etching, as a crucial part of semiconductor processes, directly impacts the performance, reliability, and yield of semiconductor chips through the good shape, uniformity, and consistent etching rate of the etched material. In the semiconductor sub-sectors of photodetectors and APDs, the performance bandwidth and reliability are directly related to the etching process. Mature and stable etching equipment and processes can not only meet performance and reliability requirements but also improve product yield. Traditional wet etching techniques often employ non-standard basket-mounted wafers, manually rotating them in an etching solution or adding axial rotation or oscillation etching. Manual rotation speed is uncontrollable, and consistency and uniformity cannot be guaranteed. Adding axial rotation or oscillation etching requires large spaces, large amounts of etching solution, and the etching solution has a strong impact on the wafer, easily causing cracking. Axial rotation or oscillation etching cannot seal volatile etching solutions, resulting in a rapid decrease in etching rate. For multi-layered wafer structures with different materials per layer, it is necessary to observe the color to determine which layer is being etched, which is prone to over-etching. This makes it impossible for wet etching to guarantee high uniformity and consistency, leading to low yields in some mesa processes. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] Therefore, a first aspect of the present invention provides a wafer wet etching apparatus.

[0005] A second aspect of the present invention provides an etching method.

[0006] In view of this, a wafer wet etching apparatus is provided according to a first aspect of the embodiments of this application, comprising:

[0007] A barrel body, the interior of which is used to hold the corrosive liquid;

[0008] A drive assembly for driving the flow of the corrosive liquid;

[0009] A support assembly is provided for placement within the barrel. The support assembly includes multiple columns, each of which has a slot. The wafer is positioned within the barrel via the slot and the multiple columns.

[0010] In one feasible implementation, the carrier component includes:

[0011] A first fixing base, on which a plurality of assembly ports and at least one card interface are formed;

[0012] In this configuration, at least one of the multiple columns is detachably connected to the first fixing base via the card interface, while the other columns are connected to the first fixing base via the assembly port.

[0013] The second fixing seat is connected to the other end of the column, and the second fixing seat is used to be installed inside the barrel.

[0014] In one feasible implementation, the second fixing seat has a stepped surface and a hollow portion formed thereon.

[0015] In one feasible implementation, each of the columns has a plurality of the slots formed along the height direction.

[0016] In one feasible implementation, on each of the columns, the density of the slot distribution gradually increases in the direction toward the barrel body.

[0017] In one feasible implementation, the top surface of the slot is an inclined surface.

[0018] In one feasible implementation, the driving component includes:

[0019] A magnetic motor, wherein the magnetic motor is disposed within a partition of the barrel body;

[0020] A magnetic rotor is disposed inside the barrel, and a magnetic motor is used to drive the magnetic rotor to rotate.

[0021] In one feasible implementation, the wafer wet etching apparatus further includes:

[0022] A positioning post is provided on the barrel or the bearing assembly, and a through hole is formed on the magnetic rotor, through which the positioning post passes.

[0023] In one possible implementation, the inner diameter of the barrel gradually increases in the direction from the highest point to the lowest point of the barrel.

[0024] According to a second aspect of the embodiments of this application, an etching method is provided, applied to a wafer wet etching apparatus as described in any of the above technical solutions, the etching method comprising:

[0025] The wafer is connected to the column through the slot;

[0026] The load-bearing component is disposed inside the barrel;

[0027] The drive assembly drives the flow of the etching solution inside the tank, thereby etching the wafer.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] The wafer wet etching apparatus provided in this application includes a tank, a drive assembly, and a support assembly. The support assembly includes multiple pillars, each with a slot. Based on this, in use, the wafer wet etching apparatus provided in this application allows the wafer to be first secured to the pillars via the slots. Then, the support assembly, along with the wafer, is placed in the tank. The drive assembly drives the flow of etching solution within the tank, allowing the etching solution to wet-etch the wafer. This application replaces the traditional method of manually rotating the wafer by using a drive assembly to move the etching solution. On one hand, the controllable flow rate of the etching solution improves the efficiency of wet etching; on the other hand, it ensures the consistency and uniformity of the wet etching process. Attached Figure Description

[0030] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0031] Figure 1 A schematic structural diagram of a wafer wet etching apparatus according to an embodiment of this application;

[0032] Figure 2 A schematic structural diagram of the magnetic rotor of the drive assembly of a wafer wet etching apparatus according to an embodiment of this application;

[0033] Figure 3 A schematic structural diagram of the second fixture of a wafer wet etching apparatus according to an embodiment of this application;

[0034] Figure 4 A schematic structural diagram of a column of a wafer wet etching apparatus according to an embodiment of this application;

[0035] Figure 5 A schematic structural diagram of another column of a wafer wet etching apparatus provided in this application;

[0036] Figure 6 This is a schematic flowchart illustrating the etching method of one embodiment provided in this application.

[0037] in, Figures 1 to 5 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0038] 110 tank body, 120 drive assembly, 130 load-bearing assembly, 140 positioning column;

[0039] 121 Magnetic rotor, 122 Through hole, 131 Column, 132 Slot, 133 First fixing seat, 134 Second fixing seat, 135 Stepped surface, 136 Hollowed-out part. Detailed Implementation

[0040] To better understand the above technical solutions, the technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0041] like Figures 1 to 5 As shown, a wafer wet etching apparatus is provided according to a first aspect of the present application, comprising: a barrel 110 for holding an etching solution; a drive assembly 120 for driving the flow of the etching solution; and a support assembly 130 for being disposed within the barrel 110, the support assembly 130 including a plurality of pillars 131, each pillar 131 having a slot 132 formed thereon, the wafer being positioned within the barrel 110 via the slots 132 and the plurality of pillars 131.

[0042] The wafer wet etching apparatus provided in this application includes a tank 110, a drive assembly 120, and a support assembly 130. The support assembly 130 includes multiple pillars 131, each pillar 131 having a slot 132. Based on this, in use, the wafer wet etching apparatus provided in this application allows the wafer to be first secured to the multiple pillars 131 via the slots 132. Then, the support assembly 130 connects the wafer and places it inside the tank 110. The drive assembly 120 drives the flow of etching solution within the tank 110, allowing the etching solution to perform wet etching on the wafer. This application replaces the traditional method of manually rotating the wafer by using the drive assembly 120 to drive the flow of etching solution. On one hand, the controllable flow rate of the etching solution improves the efficiency of wet etching; on the other hand, it ensures the consistency and uniformity of wet etching, making it suitable for mass production of wafer etching.

[0043] like Figures 1 to 5As shown, in one feasible embodiment, the supporting component 130 includes: a first fixing base 133, on which a plurality of assembly ports and at least one card slot are formed; wherein, at least one of the plurality of uprights 131 is detachably connected to the first fixing base 133 through the card slot, and the other uprights 131 are connected to the first fixing base 133 through the assembly ports; and a second fixing base 134, on which the other end of the uprights 131 is connected, and the second fixing base 134 is used to be disposed inside the barrel body 110.

[0044] In this technical solution, a further design for the support component 130 is provided. Besides the uprights 131, the support component 130 may also include a first fixing seat 133 and a second fixing seat 134. The first fixing seat 133 can be arranged at the top, while the second fixing seat 134 can be arranged at the bottom. Furthermore, at least one of the uprights 131 is detachably connected to the first fixing seat 133 via a snap-fit ​​interface, and the other uprights 131 are connected to the first fixing seat 133 via the assembly port. Based on this, during use… In this process, some of the multiple posts 131 can be connected to the assembly port first. In this case, the multiple posts 131 can open up a relatively large space, and the wafer can be placed in the space enclosed by the multiple posts 131. Then, the wafer is placed in the slots 132 in the multiple posts 131. Finally, the other posts 131 are placed at the card interface. The slots 132 on these posts 131 are also engaged with the wafer, which completes the wafer fixation and can prevent the wafer from shaking during wet etching, thus affecting the etching effect.

[0045] In some examples, there can be four posts 131, with one of the four posts 131 connected to the card interface and the others connected to the assembly port. This setup can both fix the wafer and minimize the number of posts 131. The four posts 131 form four support points around the circumference of the wafer, ensuring that every area of ​​the wafer can be etched by the etchant. This avoids the problem of some areas of the wafer not being etched due to an excessively large clamping area, and also prevents the wafer from floating and colliding during rotation without being fixed in the liquid, which could lead to breakage.

[0046] In some examples, an arc-shaped handle may also be provided on the first mounting base 133 to facilitate the user's handling of the wafer and carrier assembly 130, making the use of the wafer wet etching apparatus safer. Understandably, to facilitate the user's handling of the carrier assembly 130, the handle may also be arranged on both sides of the first mounting base 133.

[0047] like Figures 1 to 5 As shown, in one feasible embodiment, the second fixing seat 134 has a stepped surface 135 and a hollow portion 136 formed on it.

[0048] In this technical solution, a second fixing seat 134 is further provided. The second fixing seat 134 has a stepped surface 135 and a hollow part 136. This setting can ensure the fluidity of the liquid when the drive component 120 is turned on, and can prevent the drive component 120 from contacting the wafer, thus ensuring the efficiency of wet etching and etching.

[0049] like Figures 1 to 5 As shown, in one feasible implementation, each column 131 has a plurality of slots 132 formed along the height direction.

[0050] In this technical solution, multiple slots 132 can be formed on each column 131. Based on this, multiple wafers can be fixed by multiple columns 131. Multiple wafers can be stacked along the height direction of the column 131, which can further improve the etching efficiency of the wafer wet etching device.

[0051] In one feasible implementation, on each column 131, the density of the slots 132 distributed in the direction closer to the barrel 110 gradually increases.

[0052] In this technical solution, with multiple slots 132 formed on the column 131, a distribution trend of the slots 132 is further provided. On each column 131, the density of the slots 132 gradually increases in the direction closer to the barrel 110. That is, the distance between two adjacent slots 132 is longer closer to the top of the column 131, and conversely, the distance between two adjacent slots 132 is shorter closer to the bottom of the column 131. This arrangement takes into account that when the etching liquid is driven to flow by the drive component 120, the liquid flow rate at the bottom of the barrel 110 may be higher. Through this arrangement of slots 132, the etching efficiency of the wafers located at the top of the barrel 110 can be the same as or close to the etching efficiency of the wafers at the bottom, which can further ensure the consistency of etching.

[0053] In one feasible implementation, the top surface of the slot 132 is an inclined surface.

[0054] In this technical solution, the design of the card slot 132 is further provided. The top surface of the card slot 132 is a slope. Based on this, the contact area between the card slot 132 and the wafer can be reduced. This can prevent the wafer from becoming loose and minimize the obstruction of the wafer caused by the setting of the card slot 132. This allows more areas of the wafer to be etched and improves the etching effect.

[0055] In some examples, the bottom surface of the slot 132 can be a flat surface, which allows the slot 132 to better support the wafer and reduce the probability of the wafer slipping during loading.

[0056] In one feasible implementation, the drive assembly 120 includes: a magnetic motor disposed within a partition of the barrel 110; and a magnetic rotor 121 disposed within the barrel 110, wherein the magnetic motor is used to drive the magnetic rotor 121 to rotate.

[0057] In this technical solution, a further design of the drive assembly 120 is provided. The drive assembly 120 may include a magnetic motor and a magnetic rotor 121. The magnetic motor is disposed in the partition of the tank 110, and the magnetic rotor 121 is disposed in the tank 110. Based on this, the magnetic motor can drive the magnetic rotor 121 to rotate in a non-contact manner, thereby driving the liquid stored in the tank 110 to rotate. Based on this, the service life of the drive assembly 120 can be guaranteed, and the contamination of the corrosive liquid due to the setting of the drive assembly 120 can be avoided, thus ensuring the sealing of the corrosive liquid.

[0058] In this technical solution, the magnetic rotor 121 is used in combination with the stepped surface 135 and the hollowed-out portion 136 on the second fixed base 134. The hollowed-out portion 136, formed by opening up the area below the stepped surface 135 (excluding the support and positioning areas), ensures the fluidity of the liquid during the rotation of the magnetic rotor 121. The rotation of the magnetic rotor 121 drives the liquid to rotate, replacing the manual basket etching process, increasing the fluidity of the etching solution. This not only makes the speed controllable but also improves consistency and uniformity. Using the magnetic rotor 121 to drive the liquid flow instead of the traditional basket etching method allows for observation of color changes on the etched surface of the wafer during the process, enabling control over the cessation of etching. This prevents over-etching caused by differences in etching solution quality and facilitates the assessment of etching depth.

[0059] In one feasible embodiment, the wafer wet etching apparatus further includes: a positioning post 140, which is disposed on the barrel 110 or the support assembly 130, and a through hole 122 is formed on the magnetic rotor 121, through which the positioning post 140 passes.

[0060] In this technical solution, the wafer wet etching apparatus may also include a positioning post 140, and a through hole 122 may be formed on the magnetic rotor 121. The positioning post 140 can position the magnetic rotor 121 by passing through the through hole 122, which can make the flow of the etching liquid more uniform and thus improve the etching effect.

[0061] In one feasible implementation, the inner diameter of the barrel 110 gradually increases in the direction from the highest point to the lowest point of the barrel 110.

[0062] In this technical solution, the style of the barrel 110 is further provided. In the direction from the high point to the low point of the barrel 110, the inner diameter of the barrel 110 gradually increases. That is to say, in the height direction of the barrel 110, it has a trend of being smaller at the top and larger at the bottom. Considering that when the etch liquid is driven to flow by the drive component 120, the liquid flow rate at the bottom of the barrel 110 may be higher, this barrel 110 structural design can make the etching efficiency of the wafer at the top of the barrel 110 the same or close to that of the wafer at the bottom, which can further ensure the consistency of etching.

[0063] In some examples, the wafer wet etching apparatus may also include a cover, which may be mounted on the barrel 110. The cover may enclose the carrier assembly 130 to improve sealing.

[0064] In some examples, a pouring section may be formed on the barrel 110 for pouring out the corrosive liquid inside the barrel.

[0065] like Figure 6 As shown, a second aspect of the embodiments of this application provides an etching method applied to a wafer wet etching apparatus as described in any of the above technical solutions. The etching method includes:

[0066] Step 201: Connect the wafer to the post via the slot;

[0067] Step 202: Install the support assembly inside the barrel;

[0068] Step 203: Drive the flow of the etching solution inside the tank through the drive component, and use the etching solution to etch the wafer.

[0069] The etching method provided in this application embodiment, since it is applied to the wafer wet etching apparatus of any of the above technical solutions, therefore has all the beneficial effects of the wafer wet etching apparatus of the above technical solutions.

[0070] In some examples, the etching method may specifically include the following steps:

[0071] 1. Apply photoresist to the back of the wafer and cure it on a hot plate at 120°C for 3 minutes to protect the back of the wafer and prevent it from being etched, which would affect the etching rate.

[0072] 2. Remove the magnetic rotor and place it on the positioning column. Then, place the wafers sequentially on the column of the wafer wet etching apparatus.

[0073] 3. Pour the prepared bromine water corrosion solution into the container and place it on a magnetic stirrer.

[0074] 4. Place the carrier assembly containing the wafer into the etching solution, start the timer and turn on the magnetic stirrer to adjust the speed to 220 rpm.

[0075] 5. Observe the color change of the wafer surface during the etching process. After the first Inp layer is etched and the color changes, the second InGaAsP+InGaAs layer changes color, the third InAlAs layer changes color, and the fourth Inp layer changes color. After etching for a total of 8-10 minutes, remove the carrier component and rinse it clean with deionized water.

[0076] 6. Remove the wafer and use a profilometer to test the etching depth.

[0077] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0078] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0079] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0080] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A wafer wet etching apparatus, characterized in that, include: A barrel body, the interior of which is used to hold the corrosive liquid; A drive assembly for driving the flow of the corrosive liquid; A support assembly is provided for placement within the barrel. The support assembly includes multiple columns, each column having a slot. The wafer is positioned within the barrel via the slot and the multiple columns. The support assembly further includes a first fixing seat and a second fixing seat. The first fixing seat is located at the top, and the second fixing seat is located at the bottom. One end of each column is connected to the first fixing seat, and the other end is connected to the second fixing seat. The top surface of the card slot is a slope; Each of the columns has multiple slots formed along its height direction; On each of the columns, the density of the slots gradually increases along the direction from the top of the column to the bottom of the column; The inner diameter of the barrel gradually increases in the direction from the highest point to the lowest point of the barrel. The driver components include: A magnetic motor, wherein the magnetic motor is disposed within a partition of the barrel body; A magnetic rotor is disposed inside the barrel, and a magnetic motor is used to drive the magnetic rotor to rotate. A positioning post is provided on a second fixed base, and a through hole is formed on the magnetic rotor, through which the positioning post passes.

2. The wafer wet etching apparatus according to claim 1, characterized in that, The bearing component include: The first fixing base has multiple assembly ports and at least one card interface; In this configuration, at least one of the multiple columns is detachably connected to the first fixing base via the card interface, while the other columns are connected to the first fixing base via the assembly port. The other end of the column is connected to the second fixing seat, which is used to be installed inside the barrel.

3. The wafer wet etching apparatus according to claim 2, characterized in that, The second fixing seat has a stepped surface and a hollow part.

4. An etching method, characterized in that, The wafer wet etching apparatus used in any one of claims 1 to 3, the etching method comprising: The wafer is connected to the column through the slot; The load-bearing component is disposed inside the barrel; The drive assembly drives the flow of the etching solution inside the tank, thereby etching the wafer.

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