Wafer process machine
By setting a guide in the process cavity of the wafer process machine to tilt the wafer box, the problem of roughness on the back of the wafer and black edges in the wet etching process is solved, and a more uniform etching effect is achieved.
Patent Information
- Application Number
- CN202421923896.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-08
- Publication Date
- 2025-06-06
- Estimated Expiration
- 2034-08-08
AI Technical Summary
In the wet etching process of wafers, the high viscosity of sulfuric acid causes the gas to be wrapped into small bubbles in the etching liquid, hindering corrosion in local areas and causing the problem of rough surface and edges on the back of the wafer to turn black.
A wafer process machine is designed, by setting a guide in the process cavity to tilt the wafer box, causing the back of the wafer to tilt upward, so that the generated bubbles directly leave the wafer.
It effectively avoids vertical stripes and black edges on the back of the wafer, and improves the surface quality after etching.
Smart Images
Figure CN222953061U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the semiconductor field, in particular to a wafer process machine. Background Art
[0002] In the wet etching (WET) backside thinning process of the wafer, when using a spin etching (SPIN E) solution to etch the silicon on the backside of the wafer (Wafer), sulfuric acid (H2O) is added to the silicon (Si) etching solution system. 2 SO 4 ), the roughness of the wafer surface after etching can be controlled. Observing the reaction mechanism of Si etching above, it can be seen that nitrogen dioxide (NO 2 ) Gas is generated, the reaction formula is as follows: Si + 4HNO 3 +6HF=H 2 SiF 6 +4NO 2 +4H 2 O. Due to H 2 SO 4 The viscosity is relatively large, and these gases will be absorbed by H 2 SO 4 The gas is wrapped into small bubbles, which hinders the corrosion of the local area and forms a rough surface with pits after corrosion. During the etching process, the gas rises continuously and produces vertical stripes when passing through the wafer surface.
[0003] See also Figure 1 , which is a schematic diagram of the structure of a wafer box (Carrier) in the prior art. Before processing, a film will be applied to the front of the wafer to prevent corrosion of the front device. The wafer is placed vertically in the carrier. When it is immersed in the rotating etching solution, bubbles will rise along the surface of the wafer to produce vertical stripes, such as Figure 2 As shown in the figure, the wafer reacts in the rotating etching solution, the wafer floats up, and the gas at the contact point between the wafer and the carrier does not float up smoothly. The gas accumulates and causes black color difference at the edge of the wafer, as shown in the figure. Figure 3 As shown, the visual inspection of shipment results in the problem of unqualified appearance.
[0004] Therefore, how to prevent the wet etching process from causing vertical color difference on the back of the wafer and blackening of the wafer edge is a problem that needs to be solved at present. Summary of the invention
[0005] The technical problem to be solved by the utility model is how to prevent vertical color difference on the back of a wafer and blackening of the edge of the wafer caused by a wet etching process, and provides a wafer process machine.
[0006] In order to solve the above problems, the utility model provides a wafer processing machine, including: a process chamber; a guide located in the process chamber; and a wafer box located in the process chamber and arranged on the guide, for loading wafers, the loading side of the wafer box for loading wafers partially contacts the back side of the loaded wafer; the guide can tilt the wafer box so that the back side of the loaded wafer is tilted upward.
[0007] In some embodiments, the guide further includes: a base, located at the bottom of the process chamber, for supporting the wafer box; a connecting rod, connected to the base, for controlling the tilt of the base to drive the wafer box to tilt.
[0008] In some embodiments, the wafer box includes a bottom wall and two side walls arranged opposite to each other, and each of the side walls further includes: a plurality of isolation strips, the isolation strips extending in a direction perpendicular to the bottom wall and arranged in a direction parallel to the bottom wall, and a receiving space is formed between two adjacent isolation strips for receiving the edge of the wafer, a protrusion is provided on the first side of the isolation strip, wherein the first side serves as the loading side of the wafer box for loading the wafer and is close to the back side of the wafer when in use, and the protrusion is used to support the back side of the wafer; at least one fixing strip, the fixing strip extending in a direction parallel to the bottom wall and connected to the plurality of isolation strips to fix the plurality of isolation strips.
[0009] In some embodiments, the protrusion includes a top surface contacting the back surface of the wafer and a bottom surface contacting the first side of the isolation bar, and an area of the top surface is smaller than an area of the bottom surface.
[0010] In some embodiments, the height of the protrusion from the bottom to the top is 2 to 3 mm; the distance from the top of the protrusion to the adjacent isolation strip is 8 to 10 mm.
[0011] In some embodiments, a limit block is disposed at one end of two adjacent isolation bars close to the fixing bar.
[0012] In some embodiments, the distance between two adjacent isolation strips is 10 mm to 13 mm, and the wafer box can accommodate 13 wafers.
[0013] In some embodiments, there are multiple fixing bars, and the multiple fixing bars are arranged in a direction perpendicular to the bottom wall.
[0014] In some embodiments, the isolation strip intersects with the plurality of fixing strips and extends to the bottom wall.
[0015] In some embodiments, there are two fixing bars, and the isolation bar is located between the two fixing bars.
[0016] The above technical solution, by arranging a guide in the process chamber and arranging the wafer box on the guide, the guide makes the back side of the wafer tilt upward, so that the bubbles generated on the back side of the wafer can be separated from the wafer as directly as possible. Since the bubbles staying on the back side of the wafer will cause uneven etching when they slowly rise along the vertical wafer surface, thereby generating vertical stripes, the back side of the wafer is arranged to tilt upward so that the bubbles can be separated from the back side of the wafer as directly as possible, which can avoid the generation of vertical stripes on the back side of the wafer.
[0017] It should be understood that the above general description and the detailed description below are only exemplary and explanatory and cannot limit the present invention. The techniques, methods and devices known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the techniques, methods and devices should be considered as part of the authorization specification. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the specific implementation of the utility model, the following is a brief introduction to the drawings required for the description of the specific implementation. Obviously, the drawings described below are only some specific implementations of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0019] Figure 1 It is a schematic diagram of the structure of a wafer box in the prior art.
[0020] Figure 2 Schematic diagram of vertical stripes generated on the wafer surface after etching.
[0021] Figure 3 Schematic diagram of the black color difference appearing at the edge of the wafer after etching.
[0022] Figure 4 It is a structural schematic diagram of an embodiment of the wafer processing machine of the utility model.
[0023] Figure 5 It is a structural schematic diagram of an embodiment of a wafer box of the wafer processing machine of the utility model.
[0024] Figure 6 for Figure 5 A partial enlarged view of part A.
[0025] Figure 7 It is a schematic diagram of the state of the wafer in the wafer box when the process is in progress in one embodiment of the wafer processing machine described in the utility model.
[0026] Figure 8 It is a schematic diagram of the contact position between the protrusion of the wafer box and the wafer according to an embodiment of the wafer processing machine of the present invention.
[0027] Fig. 9 It is a structural schematic diagram of another embodiment of the wafer box of the wafer processing machine described in the utility model. DETAILED DESCRIPTION
[0028] The technical scheme in the embodiment of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.
[0029] In order to solve the problem of vertical stripes on the wafer surface after etching, the utility model provides a wafer processing machine, which can make the back of the wafer tilt upward during the process, so that the bubbles on the back of the wafer can be directly separated from the wafer. Figure 4 , which is a schematic diagram of the structure of an embodiment of the wafer processing machine of the utility model. Figure 4 As shown, the wafer processing machine includes: a process chamber 41, a guide 42, and a wafer box 43. The guide 42 is located in the process chamber 41. The wafer box 43 is located in the process chamber 41 and is arranged on the guide 42, and is used to load wafers. The loading side of the wafer box 43 for loading wafers contacts the back side of the loaded wafers. The guide 42 can tilt the wafer box 43 so that the back side of the loaded wafer is tilted upward.
[0030] The above technical solution, by arranging a guide in the process chamber and arranging the wafer box on the guide, the guide makes the back side of the wafer tilt upward, so that the bubbles generated on the back side of the wafer can be separated from the wafer as directly as possible. Since the bubbles staying on the back side of the wafer will cause uneven etching when they slowly rise along the vertical wafer surface, thereby generating vertical stripes, the back side of the wafer is arranged to tilt upward so that the bubbles can be separated from the back side of the wafer as directly as possible, which can avoid the generation of vertical stripes on the back side of the wafer.
[0031] In some embodiments, the guide 42 further includes: a base 421 and a connecting rod 422. The base 421 is located at the bottom of the process chamber 41 and is used to carry the wafer box 43. The connecting rod 422 is connected to the base 421 and is used to control the base 421 to tilt so as to drive the wafer box 43 to tilt.
[0032] In order to solve the problem of black color difference on the edge of the wafer after etching, the utility model provides a wafer box. Figure 5-6 ,in, Figure 5 It is a structural schematic diagram of an embodiment of a wafer box of the wafer processing machine of the utility model; Figure 6 for Figure 5A partial enlarged view of part A in the figure. Figure 5-6 As shown, the wafer box includes a bottom wall 51 and two side walls 52 arranged opposite to each other, and each of the side walls 52 further includes: a plurality of isolation bars 53 and at least one fixing bar 54. The isolation bars 53 extend in a direction perpendicular to the bottom wall 51 and are arranged in a direction parallel to the bottom wall 51. An accommodation space is formed between two adjacent isolation bars 53 for accommodating the edge of the wafer 59. A protrusion 530 is provided on the first side S1 of the isolation bar 53, wherein the first side S1 serves as the loading side of the wafer box for loading the wafer 59 and is close to the back side S0 of the wafer 59 when in use, and the protrusion 530 is used to support the back side S0 of the wafer 59. The fixing bar 54 extends in a direction parallel to the bottom wall 51 and is connected to the plurality of isolation bars 53 to fix the plurality of isolation bars 53.
[0033] See also Figure 7-Figure 8 ,in, Figure 7 This is a schematic diagram of the state of the wafer in the wafer box when the process is being carried out in an embodiment of the wafer processing machine of the utility model; Figure 8 The figure is a schematic diagram of the contact position between the protrusion of the wafer box and the wafer in an embodiment of the wafer processing machine of the utility model. The wafer 59 floats in the etching solution during the wet etching process. Figure 7 As shown in FIG. 1 , since the back side S0 of the wafer 59 is tilted upward, the back side S0 of the wafer 59 will float upward to the first side S1 of the isolation bar 53, causing the gas at the contact position between the wafer 59 and the isolation bar 53 to float up poorly, resulting in gas accumulation and the appearance of black color difference. Therefore, by providing a protrusion 530 on the first side S1 of the isolation bar 53, as shown in FIG. Figure 8 As shown, the contact point between the wafer 59 and the protrusion 530 is the position indicated by the number 81, and the wafer accommodating spaces of the two side walls 52 respectively accommodate and fix the edges of the wafer 59 to fix the wafer. The contact portion between the wafer 59 and the protrusion 530 is only four contact points, so that the back side S0 of the wafer 59 does not contact the isolation strip 53 of the wafer box as much as possible, and the gas generated at the edge of the wafer 59 can flow out as quickly as possible to avoid gas accumulation causing black color difference at the edge of the wafer 59.
[0034] In some embodiments, the protrusion 530 includes a top 531 in contact with the back side S0 of the wafer 59 and a bottom 532 in contact with the first side S1 of the isolation bar 53, and the area of the top 531 is smaller than the area of the bottom 532. In this embodiment, the shape of the protrusion 530 is a triangle, and the top 531 is a point with an area of 0. In other embodiments, the protrusion 530 may also be semicircular or trapezoidal.
[0035] In some embodiments, the height P1 of the protrusion 530 from the bottom surface 532 to the top 531 is 2 to 3 mm. In this embodiment, the height P1 of the protrusion 530 from the bottom surface 532 to the top 531 is 2.5 mm. In other embodiments, the height P1 of the protrusion 530 from the bottom surface 532 to the top 531 can also be 2 mm or 3 mm. The height P1 of the protrusion 530 from the bottom surface 532 to the top 531 is the distance from the back surface S0 of the wafer 59 to the first side S1 of the isolation strip 53. Maintaining an appropriate distance can make the gas generated at the edge of the wafer 59 flow out as quickly as possible, avoiding gas accumulation and causing black color difference at the edge of the wafer 59.
[0036] In some embodiments, the distance P2 between the top 531 of the protrusion 530 and the adjacent isolation strip 53 is 8 mm to 10 mm. In this embodiment, the distance P2 between the top 531 of the protrusion 530 and the adjacent isolation strip 53 is 8 mm. In other embodiments, the distance P2 between the top 531 of the protrusion 530 and the adjacent isolation strip 53 may also be 9 mm or 10 mm.
[0037] In some embodiments, the number of the protrusions 530 of each isolation bar 53 is 2. In other embodiments, the number of the protrusions 530 of each isolation bar 53 may also be 3 or 4, so as to further stabilize the wafer 59 and prevent the wafer 59 from shifting due to uneven force.
[0038] In some embodiments, a limit block 533 is provided at one end of two adjacent isolation bars 53 close to the fixing bar 54 to further limit the position of the wafer 59 in the wafer box to prevent the wafer 59 from shifting.
[0039] In some embodiments, the wafer box can accommodate 13 wafers 59. Since protrusions 530 need to be provided between the isolation bars 53, the spacing between the isolation bars of the traditional wafer box cannot meet the space requirement, so the standard wafer box that can accommodate 26 wafers is modified to a wafer box that can accommodate 13 wafers to meet the space requirement.
[0040] In some embodiments, the distance P3 between two adjacent isolation strips 53 is 10 mm to 13 mm. In this embodiment, the distance P3 between two adjacent isolation strips 53 is 13 mm. In other embodiments, the distance P3 between two adjacent isolation strips 53 may also be 10 mm, 11 mm or 12 mm.
[0041] In some embodiments, there are multiple fixing bars 54 , and the multiple fixing bars 54 are arranged in a direction perpendicular to the bottom wall 51 .
[0042] like Figure 5 As shown, in this embodiment, the isolation strip 53 and the plurality of fixing strips 54 intersect and extend to the bottom wall 51 .
[0043] See also Fig. 9 , which is a structural schematic diagram of another embodiment of the wafer box of the wafer process machine described in the utility model. Fig. 9 The embodiment shown is Figure 5 The embodiment shown is different in that there are two fixing bars 94, and the isolation bar 93 is located between the two fixing bars 94. When used in an environment with sufficient load-bearing capacity and low processing temperature, only the isolation bar 93 between the two fixing bars 94 can be retained to increase the fluidity of the etching solution and bubbles, keep the shielding away from the back of the wafer as far as possible, and let the gas generated at the edge of the wafer flow out as quickly as possible to avoid gas accumulation causing black color difference at the edge of the wafer.
[0044] It should be noted that references in the specification to "an embodiment", "an embodiment", "an exemplary embodiment", "some embodiments", etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, whether or not explicitly described, it is within the knowledge of a technician in the relevant art to implement such feature, structure, or characteristic in conjunction with other embodiments.
[0045] Typically, a term can be understood at least in part from usage in context. For example, the term "one or more" as used herein depends at least in part on the context and can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a combination of features, structures or features in a plural sense. Similarly, terms such as "one", "a" or "the" can also be understood to express singular usage or to express plural usage, depending at least in part on the context. In addition, the term "based on" can be understood to not necessarily be intended to express a set of exclusive factors, but can alternatively, also at least in part depending on the context, allow for the presence of other factors that are not necessarily explicitly described. It should also be noted in this specification that "connected / coupled" refers not only to the direct coupling of one component to another component, but also to the indirect coupling of one component to another component through an intermediate component.
[0046] It should be noted that the terms "including" and "having" and their variations involved in the documents of the present utility model are intended to cover non-exclusive inclusions. The terms "first", "second", etc. are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Unless the context clearly indicates otherwise, it should be understood that the data used in this way can be interchanged under appropriate circumstances. In addition, the embodiments of the present utility model and the features in the embodiments can be combined with each other unless there is a conflict. In addition, in the above description, the description of well-known components and technologies is omitted to avoid unnecessary confusion of the concepts of the present utility model. In the above-mentioned embodiments, each embodiment focuses on the differences from other embodiments, and the same / similar parts between the embodiments can be referred to each other.
[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.
Claims
1. A wafer processing machine, characterized in that: include: Process cavity; A guide, located in the process chamber; as well as A wafer box, located in the process chamber and disposed on the guide, for loading wafers, wherein a loading side portion of the wafer box for loading wafers contacts a back side of the loaded wafers; The guide can tilt the wafer box so that the back side of the loaded wafers is tilted upward.
2. The wafer processing machine according to claim 1, characterized in that: The guide further comprises: A base, located at the bottom of the process chamber, for carrying the wafer box; A connecting rod is connected to the base and is used to control the base to tilt so as to drive the wafer box to tilt.
3. The wafer processing machine according to claim 1, characterized in that: The wafer box comprises a bottom wall and two side walls arranged opposite to each other, each of the side walls further comprising: A plurality of isolation bars, the isolation bars extending in a direction perpendicular to the bottom wall and arranged in a direction parallel to the bottom wall, a receiving space being formed between two adjacent isolation bars for receiving the edge of a wafer, a first side of the isolation bar being provided with a protrusion, wherein the first side serves as a loading side for the wafer box to load the wafer and is close to the back side of the wafer when in use, and the protrusion is used to support the back side of the wafer; At least one fixing strip extends in a direction parallel to the bottom wall and is connected to the plurality of isolation strips to fix the plurality of isolation strips.
4. The wafer processing machine according to claim 3, characterized in that: The protrusion includes a top surface contacting the back surface of the wafer and a bottom surface contacting the first side of the isolation bar, and an area of the top surface is smaller than an area of the bottom surface.
5. The wafer processing machine according to claim 4, characterized in that: The height of the protrusion from the bottom to the top is 2 to 3 mm; The distance between the top of the protrusion and the adjacent isolation strip is 8 to 10 mm.
6. The wafer processing machine according to claim 3, characterized in that: A limiting block is provided at one end of two adjacent isolation strips close to the fixing strip.
7. The wafer processing machine according to claim 3, characterized in that: The distance between two adjacent isolation strips is 10 mm to 13 mm, and the wafer box can accommodate 13 wafers.
8. The wafer processing machine according to claim 3, characterized in that: There are multiple fixing bars, and the multiple fixing bars are arranged in a direction perpendicular to the bottom wall.
9. The wafer processing machine according to claim 8, characterized in that: The isolation strip intersects with the plurality of fixing strips and extends to the bottom wall.
10. The wafer processing machine according to claim 3, characterized in that: There are two fixing strips, and the isolation strip is located between the two fixing strips.