Photolithography wafer tray and method of making same

Abstract

This invention discloses a photolithography wafer tray and its manufacturing method. The photolithography wafer tray includes a tray body and a limiting member with elastic deformation. The tray body is provided with a receiving groove for accommodating wafers. The limiting member is disposed on the tray body and extends partially into the receiving groove. The limiting member can provide a holding force perpendicular to or along the depth direction of the receiving groove to limit the wafers in the receiving groove. The photolithography wafer tray of this invention can accurately limit the position of samples placed on it, so as to achieve high-precision alignment photolithography process for small-sized samples, while improving the compatibility of existing photolithography machines with sample sizes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro-nano processing equipment, and in particular to a photolithography wafer tray and a manufacturing method thereof. BACKGROUND

[0002] The photolithography process is a common process in the field of micro-nano processing, and is usually used for photolithography of 6-inch, 8-inch or larger whole wafer samples. However, in the research and production of third-generation semiconductor material devices, the processing process of 2-inch or small wafer samples is often used, and therefore it is necessary to manufacture a wafer tray to fix the sample on the tray and then transport the sample to a photolithography machine to realize the sample photolithography process.

[0003] The photolithography wafer tray is generally prepared by a photolithography process on a silicon wafer or a substrate to form a pattern identical to the shape of the sample, and then a groove is processed by etching or laser cutting. The groove processed by etching needs to be slightly larger than the sample to take and place the sample, and therefore the sample will move in the groove, resulting in that the sample cannot be fixed at the same position each time of photolithography. Therefore, the existing photolithography wafer tray can only realize single photolithography after loading the sample, and cannot realize alignment photolithography.

[0004] Secondly, the laser cutting processing tray is easy to break and deform, and the processing precision of the tray is not high, and the surface of the sample placed on the tray is not flat, and it is also difficult to realize alignment photolithography.

[0005] The information disclosed in this Background section is only for the purpose of increasing the understanding of the background of the application, and should not be taken as an acknowledgment or any form of suggestion that this information forms prior art that is already known to a person of ordinary skill in the art. SUMMARY

[0006] The present application aims to provide a photolithography wafer tray and a manufacturing method thereof. The photolithography wafer tray of the present application can accurately limit the sample placed thereon to realize high-precision and alignment photolithography process of small-size samples, and improve the compatibility of the existing photolithography machine for sample sizes.

[0007] To achieve the above-mentioned purpose, the embodiment of the present application provides a photolithography wafer tray, which comprises a tray body and a limiting piece with elastic deformation; the tray body is provided with a containing groove for containing a wafer; the limiting piece is arranged on the tray body and partially extends into the containing groove, and the limiting piece can provide a resisting force perpendicular to or along the depth direction of the containing groove to limit the wafer in the containing groove.

[0008] In one or more embodiments of the present application, the limiting piece is formed by etching the tray body.

[0009] In one or more embodiments of the present application, the tray body comprises a first substrate and a second substrate, the second substrate has a flat surface, the first substrate is stacked on the surface of the second substrate, the first substrate is formed with a through slot and a limiting member.

[0010] In one or more embodiments of the present application, the tray body is provided with a mounting slot at the edge of the accommodating slot, the mounting slot is in communication with the accommodating slot, the limiting member is arranged in the mounting slot and partially extends into the accommodating slot from the communication part of the mounting slot and the accommodating slot.

[0011] In one or more embodiments of the present application, the limiting member has a limiting surface, when the slide is placed in the accommodating slot, the limiting surface abuts against the edge of the slide.

[0012] In one or more embodiments of the present application, in the direction from the bottom of the accommodating slot to the opening of the accommodating slot, the limiting surface is arranged to be inclined towards the center of the accommodating slot.

[0013] In one or more embodiments of the present application, a gap is formed between the bottom of the limiting member and the bottom of the accommodating slot.

[0014] In one or more embodiments of the present application, the tray body is provided with a plurality of limiting members, and the plurality of limiting members provide abutting forces in different directions perpendicular to the depth direction of the accommodating slot.

[0015] In one or more embodiments of the present application, the limiting member is arranged in an S shape or a Z shape.

[0016] In one or more embodiments of the present application, in the direction from the bottom of the accommodating slot to the opening of the accommodating slot, the side wall of the accommodating slot is arranged to be inclined towards the center of the accommodating slot.

[0017] An embodiment of the present application also provides a manufacturing method of the above-mentioned photolithography slide tray, comprising: providing a first substrate, forming a through slot on the first substrate, and forming a limiting member at the edge of the through slot; providing a second substrate; and bonding the first substrate on the second substrate.

[0018] In one or more embodiments of the present application, the through slot and the limiting member are prepared by a dry etching process, a laser process or a wet etching process.

[0019] In one or more embodiments of the present invention, the step of forming a through-slot on the first substrate and forming a limiting member at the edge of the through-slot includes: drawing a through-slot pattern on the first substrate, the through-slot pattern having the same size as the wafer, and drawing a limiting member pattern at the edge of the through-slot pattern; spin-coating photoresist on the first substrate and exposing it; developing, fixing, and hardening the exposed first substrate; and etching the hardened first substrate to form the through-slot and the limiting member.

[0020] In one or more embodiments of the present invention, the step of bonding the first substrate to the second substrate includes: applying an adhesive layer to a partial area of ​​the surface of the second substrate; aligning the surfaces of the first substrate and the second substrate coated with the adhesive layer and baking them together. The partial area refers to the area outside the area covered by the limiting member and not covered by the first substrate.

[0021] Compared with existing technologies, the upper limit member structure of the photolithography tray according to the embodiments of the present invention is the most critical structure for aligning small-sized (non-standard) samples for photolithography. By setting an upper limit member integrated with the tray body and having elastic deformation on the tray body, the toughness of the upper limit member is used to fix the sample and ensure the reference position of the sample.

[0022] The photolithography substrate tray of this invention, through the inclined setting of the accommodating groove wall and the limiting surface of the limiting member, ensures that the bottom of the sample is in close contact with the bottom of the accommodating groove, thus ensuring the flatness of the sample placement.

[0023] The method for fabricating a photolithography substrate tray according to the embodiments of the present invention improves the processing accuracy and sample loading accuracy of the photolithography substrate tray by using micromachining processes such as photolithography, etching, and bonding. It is applicable to samples of different sizes and shapes, and can realize multi-layer alignment photolithography of small-sized (non-standard) samples, thereby improving the compatibility of photolithography machines and greatly helping the research and development of third-generation semiconductor materials.

[0024] The method for manufacturing the photolithography substrate tray according to the present invention utilizes dry etching, laser etching, or wet etching processes to etch the wall of the receiving groove and the limiting surface of the limiting component into an "inverted trapezoidal" shape, so that the bottom of the sample is in close contact with the bottom of the receiving groove, ensuring the flatness of the sample placement. Attached Figure Description

[0025] Figure 1 This is a top view of a photolithography substrate tray (without a sample) according to an embodiment of the present invention;

[0026] Figure 2 This is a top view of a photolithography substrate tray (for placing samples) according to an embodiment of the present invention;

[0027] Figure 3 This is a partially enlarged view of a photolithography wafer tray according to an embodiment of the present invention;

[0028] Figure 4 This is a side cross-sectional view of a photolithography substrate tray (for placing samples) according to an embodiment of the present invention;

[0029] Figure 5 This is a process flow diagram of a method for manufacturing a photolithography substrate tray according to an embodiment of the present invention. Detailed Implementation

[0030] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0031] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0032] As described in the background section, existing photolithography wafer trays typically involve creating a pattern identical to the sample shape on a silicon wafer or substrate using photolithography, followed by etching or laser cutting to create grooves. However, because the grooves created by etching need to be slightly larger than the sample for placement, the sample can move within the grooves, making it impossible to fix it in the same position for each photolithography cycle. Therefore, existing photolithography wafer trays can only achieve single-cycle photolithography after holding the sample, and cannot achieve aligned photolithography. Secondly, laser-cut trays are prone to breakage and deformation, and their low processing precision results in uneven sample surfaces, making aligned photolithography difficult to achieve as well.

[0033] To address the aforementioned technical problems, this invention proposes a photolithography substrate tray. By incorporating a limiting member with elastic deformation within the receiving groove, the sample placed within the groove is positioned to achieve high-precision alignment of the photolithography process for small-sized samples. The receiving groove, with a flat bottom surface, is formed by bonding two substrates, improving the flatness of the sample after placement.

[0034] like Figures 1 to 4 As shown, a photolithography wafer tray according to an embodiment of the present invention includes a tray body 10 and a limiting member 20 with elastic deformation. The tray body 10 is provided with a receiving groove 11 for receiving a wafer A. The limiting member 20 is disposed on the tray body 10 and partially extends into the receiving groove 11. The limiting member 20 can provide a holding force perpendicular to or along the depth direction of the receiving groove 11 to limit the wafer within the receiving groove 11. Specifically, the limiting member 20 has a limiting surface 21, which abuts against the edge of the wafer when the wafer is placed in the receiving groove 11.

[0035] For example, the limiting member 20 can be formed by etching the tray body 10, for example, etching it into an S-shape or Z-shape, that is, the limiting member 20 and the tray body 10 are integrally formed. Therefore, the material of the tray body 10 itself should have a certain elastic deformation. However, in other exemplary embodiments, the limiting member 20 can also be a separately manufactured component, with one end fixed to the tray body 10 to limit the position of the slide. The shape can also be Z-shaped, S-shaped, or other shapes that can generate a certain elastic potential energy, such as C-shaped, V-shaped, W-shaped, etc. The size of the limiting member 20 can be adaptively adjusted according to the shape of the slide sample to ensure that the position of the slide sample is basically the same each time it is placed.

[0036] In one embodiment, a mounting groove 12 is provided on the edge of the receiving groove 11 on the tray body 10. The mounting groove 12 is connected to the receiving groove 11. A limiting member 20 is provided on the groove wall of the mounting groove 12, and extends partly from the connection between the mounting groove 12 and the receiving groove 11 into the receiving groove 11. In other embodiments, the limiting member 20 may also be directly provided on the side wall of the receiving groove 11.

[0037] In one embodiment, the tray body 10 is provided with a plurality of limiting members 20, and the multiple limiting members 20 provide different or the same direction of the holding force perpendicular to the depth direction of the receiving groove, so as to further improve the stability of the slide sample placed in the receiving groove 11.

[0038] refer to Figure 4 As shown, in order to ensure that the bottom of the slide sample fits tightly against the bottom of the receiving groove 11, the sidewall of the receiving groove 11 is inclined along the direction close to the center of the groove in the direction from the bottom of the groove to the opening of the groove. Similarly, the limiting surface 21 of the limiting member 20 is inclined along the direction close to the center of the groove in the direction from the bottom of the groove to the opening of the groove. The above-mentioned inclined surface makes the sidewall of the receiving groove 11 present a shape similar to an "inverted trapezoid", so that the bottom of the slide sample fits tightly against the bottom of the receiving groove 11, ensuring that the slide sample is placed flat.

[0039] In order to improve the flatness of the bottom of the receiving groove 11 in the tray body 10 and reduce the requirements of the process for forming the receiving groove 11, in this embodiment, the tray body 10 is formed by stacking and bonding a first substrate 101 and a second substrate 102.

[0040] refer to Figure 4As shown, the second substrate 102 is preferably a silicon wafer, and the second substrate 102 has a flat first surface 1021. The first substrate 101 is also preferably a silicon wafer. A through-groove penetrating the first substrate 101 in the thickness direction can be formed on the first substrate 101 by a dry etching process, a laser process, or a wet etching process. At the same time, a limiting member 20 is etched on the side of the through-groove by a dry etching process, a laser process, or a wet etching process. The first substrate 101 is stacked on the first surface 1021 of the second substrate 102, and the through-hole mates with the first surface 1021 of the second substrate 102 to form a receiving groove 11.

[0041] The first substrate 101 and the second substrate 102 are bonded together by an adhesive layer 103, which can be photoresist, bonding adhesive, or other adhesive. Specifically, to ensure that the adhesive layer 103 does not affect the elastic deformation of the limiting member 20, a gap is formed between the bottom of the limiting member 20 and the bottom of the receiving groove 11. Furthermore, to ensure that the adhesive layer 103 does not affect the elastic deformation of the limiting member 20, no adhesive layer 103 is coated between the bottom of the limiting member 20 and the bottom of the receiving groove 11. Simultaneously, to ensure that the adhesive layer 103 does not affect the placement of the wafer sample within the receiving groove 11, the area of ​​the first surface of the second substrate 102 not covered by the first substrate 101 (the area where the receiving groove 11 is located) is not coated with the adhesive layer 103.

[0042] Compared with existing technologies, the upper limit member structure of the photolithography tray according to the embodiments of the present invention is the most critical structure for aligning small-sized (non-standard) samples for photolithography. By setting an upper limit member integrated with the tray body and having elastic deformation on the tray body, the toughness of the upper limit member is used to fix the sample and ensure the reference position of the sample.

[0043] The photolithography substrate tray of this invention, through the inclined setting of the accommodating groove wall and the limiting surface of the limiting member, ensures that the bottom of the sample is in close contact with the bottom of the accommodating groove, thus ensuring the flatness of the sample placement.

[0044] refer to Figure 5 As shown, an embodiment of the present invention also provides a method for manufacturing the above-mentioned photolithography substrate, comprising: s1, providing a first substrate, forming a through groove on the first substrate, and forming a limiting member at the edge of the through groove; s2, providing a second substrate; s3, bonding the first substrate to the second substrate.

[0045] Specifically, in step s1, the through-slot and the limiting component can be fabricated using a dry etching process, a laser process, or a wet etching process. The following describes the specific steps for forming the through-slot and the limiting component on the first substrate using a dry etching process as an example. First, a through-slot pattern is drawn on the first substrate, with the through-slot pattern having the same dimensions as the wafer sample. Alternatively, only the outer frame of the through-slot is drawn, and the substrate in the middle of the outer frame is removed after etching. A limiting component pattern is drawn on the edge of the through-slot pattern or the outer frame of the through-slot. The limiting component pattern can be a Z-shaped or S-shaped structure to fix the wafer sample. Subsequently, photoresist is spin-coated onto the first substrate and exposed. The exposed first substrate is then developed, fixed, and hardened. The development, fixing, and hardening processes are all traditional steps in semiconductor manufacturing, and since they are not the focus of this application, they will not be elaborated upon here. Next, the first substrate after hardening is subjected to dry etching to remove all substrate material in the patterned areas (substrate etching through) to form through-slots and limiting members. At the same time, the sidewalls of the through-slots and the limiting surfaces of the limiting members are etched into an inclined "inverted trapezoidal" shape. Finally, the etched first substrate is cleaned.

[0046] In step s3, firstly, photoresist or bonding adhesive (with viscosity) is applied to a portion of the surface of the second substrate and baked at a low temperature. This portion includes areas outside the region covered by the positioning member but not by the first substrate; specifically, the bottom of the receiving groove and the area between the positioning member and the second substrate are not coated with photoresist. Subsequently, the two substrates are aligned using a photolithography machine—the first substrate on top, the second substrate on the bottom, with no adhesive at the bottom of the positioning member—and then placed in a vacuum oven for baking to bond. Alternatively, the two substrates can be directly bonded together using a bonding machine to fix them together; or, other bonding and fixing methods can be used.

[0047] The method for fabricating a photolithography substrate tray according to the embodiments of the present invention improves the processing accuracy and sample loading accuracy of the photolithography substrate tray by using micromachining processes such as photolithography, etching, and bonding. It is applicable to samples of different sizes and shapes, and can realize multi-layer alignment photolithography of small-sized (non-standard) samples, thereby improving the compatibility of photolithography machines and greatly helping the research and development of third-generation semiconductor materials.

[0048] The method for manufacturing the photolithography substrate tray according to the present invention utilizes dry etching, laser etching, or wet etching processes to etch the wall of the receiving groove and the limiting surface of the limiting component into an "inverted trapezoidal" shape, so that the bottom of the sample is in close contact with the bottom of the receiving groove, ensuring the flatness of the sample placement.

[0049] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A photolithography wafer tray, characterized in that, include: The tray body has a receiving groove for accommodating the carrier; A limiting member with elastic deformation is disposed on the tray body and extends partially into the receiving groove. The limiting member can provide a holding force perpendicular to or along the depth direction of the receiving groove to limit the carrier in the receiving groove. In this configuration, the sidewall of the receiving groove is inclined along the direction close to the center of the groove in the direction from the bottom of the groove to the opening of the groove; the limiting member is formed by etching the tray body, and the limiting member has a limiting surface. When the carrier is placed in the receiving groove, the limiting surface abuts against the edge of the carrier. In the direction from the bottom of the receiving groove to the opening of the groove, the limiting surface is inclined along the direction close to the center of the groove.

2. The photolithography wafer tray as described in claim 1, characterized in that, The tray body includes a first substrate and a second substrate. The second substrate has a flat surface, and the first substrate is stacked on the surface of the second substrate. A through groove and a limiting member are formed on the first substrate.

3. The photolithography wafer tray as described in claim 1, characterized in that, The tray body has an installation groove on the edge of the receiving groove, the installation groove is connected to the receiving groove, the limiting member is disposed in the installation groove, and a portion of it extends from the connection between the installation groove and the receiving groove into the receiving groove.

4. The photolithography wafer tray as described in claim 1, characterized in that, A gap is formed between the bottom of the limiting member and the bottom of the receiving groove.

5. The photolithography wafer tray as described in claim 1, characterized in that, The tray body is provided with multiple limiting members, and the directions of the supporting force provided by the multiple limiting members perpendicular to the depth direction of the receiving groove are different.

6. A method for manufacturing a photolithography substrate tray as described in any one of claims 1-5, characterized in that, include: A first substrate is provided, a through groove is formed on the first substrate, and a limiting member is formed at the edge of the through groove; Provide a second substrate; The first substrate is bonded to the second substrate.

7. The method for manufacturing a photolithography wafer tray as described in claim 6, characterized in that, Through grooves and limiting components are prepared by dry etching, laser etching, or wet etching processes.

8. The method for manufacturing a photolithography wafer tray as described in claim 6, characterized in that, The step of forming a through groove on the first substrate and forming a limiting member at the edge of the through groove includes: A through-slot pattern is drawn on the first substrate. The through-slot pattern has the same size as the wafer. A limiting member pattern is drawn on the edge of the through-slot pattern. Photoresist is spin-coated onto the first substrate and exposed. The exposed first substrate is then developed, fixed, and hardened. The first substrate after hardening film is etched to form through grooves and limiting components; And / or, The step of bonding the first substrate to the second substrate includes: An adhesive layer is applied to a portion of the surface of the second substrate; The surfaces of the first and second substrates coated with adhesive layers are aligned and then baked together.

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