Wafer exposure method and wafer exposure equipment

Abstract

The invention relates to the technical field of wafer manufacturing, in particular to a wafer exposure method and wafer exposure device.The wafer exposure method comprises the steps that a first mark is arranged on a mask, and a second mark is arranged at the corresponding position on a wafer; enabling the second mark and the first mark to directly face each other in the first direction through manual observation; focusing the mask by a microscope, and shooting the first mark to obtain a first image; adjusting the microscope again to enable the microscope to focus on the wafer, and shooting the second mark to obtain a second image; the offset of the first mark and the offset of the second mark are obtained according to the first image and the second image, and the offset is fed back to the moving part so that the moving part can be adjusted; and exposing the wafer and the mask plate by using a light source. According to the wafer exposure method and the wafer exposure equipment provided by the invention, the film thickness of the wafer is not limited by the depth of field of a microscope, accurate alignment of wafers with different film thicknesses and the mask is realized, the film thickness range of wafer setting is expanded, the manufacturing difficulty of the thick film wafer is reduced, and the yield is improved.

Description

Technical Field

[0001] The present application relates to the field of wafer manufacturing technology, and in particular to a wafer exposure method and a wafer exposure device. Background Art

[0002] With the continuous development of information technology in modern society, the manufacturing of integrated circuits has become one of the important indicators for measuring the level of science and technology and comprehensive national strength. As one of the key processes in integrated circuit manufacturing, exposure is increasingly developing towards the characteristics of high efficiency, high quality and high reliability.

[0003] Thick film wafer is a method of manufacturing circuits and components on wafers using thick film technology. In MLCC, HTCC and other laser trimmed thick film resistor processes, thick film technology has an irreplaceable position with its advantages such as low cost, high thermal stability and high power.

[0004] During the wafer exposure process, a microscope is needed to assist in aligning the wafer with the mask to ensure the wafer photolithography accuracy. However, with the different application scenarios of thick film wafers, the film thickness of some thick film wafers even exceeds the depth of field of the microscope itself, which makes it impossible to clearly capture the mask and thick film wafer at the same time using traditional wafer exposure methods, resulting in difficulty in aligning the thick film wafer with the mask. Summary of the invention

[0005] The purpose of the present application is to provide a wafer exposure method and a wafer exposure device, so as to solve, to a certain extent, the technical problem existing in the prior art that, as the application scenarios of thick film wafers are different, the film thickness of some thick film wafers even exceeds the depth of field of the microscope itself, which makes it impossible to clearly capture the mask and the thick film wafer at the same time using the traditional wafer exposure method, resulting in difficulty in aligning the thick film wafer with the mask.

[0006] According to a first aspect of the present application, a wafer exposure method is provided, which is used in a wafer exposure device, wherein the wafer exposure device comprises a moving part for adsorbing a wafer, a supporting part for placing a mask, and a microscope, wherein the moving part is arranged on one side of the supporting part in a first direction, and the microscope is arranged on at least one side of the moving part and the supporting part in the first direction;

[0007] The wafer exposure method comprises the following steps:

[0008] Marking, setting a first mark on the mask and setting a second mark at a corresponding position on the wafer;

[0009] Pre-alignment, placing the mask on the supporting part, placing the wafer on the moving part, and driving the moving part through manual observation so that the second mark and the first mark are aligned with each other in the first direction;

[0010] photographing the mask, adjusting the microscope so that the microscope focuses on the mask, photographing the first mark, and acquiring a first image;

[0011] photographing the wafer, adjusting the microscope again so that the microscope focuses on the wafer, photographing the second mark, and acquiring a second image;

[0012] Adjusting the offset, obtaining the offset of the first mark and the second mark by comparing the first image and the second image, and feeding back the offset to the moving part to adjust the moving part so that the second mark and the first mark under the microscope are directly opposite to each other in the first direction;

[0013] Exposure: using a light source to expose both the wafer and the mask.

[0014] Preferably, between the steps of photographing the mask and photographing the wafer, the following steps are further included:

[0015] The wafer and the mask are separated, and the moving part is driven to move a predetermined distance along the first direction in a direction away from the mask.

[0016] Preferably, after the step of separating the wafer and the mask, the method further comprises:

[0017] The device error of the moving part is compensated, and the moving part is translated in the opposite direction according to the movement error of the moving part.

[0018] Preferably, the predetermined distance is 10 μm to 100 μm.

[0019] Preferably, after the marking step, the method further comprises:

[0020] Preparation: Pre-treat the wafer surface.

[0021] Preferably, the preparing step further includes:

[0022] Glue coating, performing spin coating on the surface of the wafer;

[0023] Drying: Drying the wafer after the glue coating.

[0024] Preferably, after the exposure step, the method further comprises:

[0025] Development: Develop the exposed wafer.

[0026] Preferably, the first mark is a through hole penetrating the mask along the first direction;

[0027] The second mark is a mark set on the surface of the wafer, and the shape of the mark is adapted to the shape of the through hole.

[0028] Preferably, both the through hole and the mark are in a cross shape.

[0029] According to the second aspect of the present application, a wafer exposure device is provided, comprising the above-mentioned moving part, the supporting part and the microscope, and using the wafer exposure method described in any of the above-mentioned technical solutions, and thus having all the beneficial technical effects of the wafer exposure method, which will not be repeated here.

[0030] Compared with the prior art, the beneficial effects of this application are:

[0031] The wafer exposure method provided by the present application, according to the wafer exposure method provided by the present application, first adjust the microscope focusing mask on the supporting part to obtain a clear image of the first mark (i.e., the first image), then adjust the microscope focusing wafer on the moving part to obtain a clear image of the second mark (i.e., the second image), and obtain the offset of the first mark and the second mark by comparing the first image and the second image, and adjust the moving part according to the offset, so as to achieve the second mark under the microscope and the first mark facing each other in the first direction, so as to complete the alignment of the wafer and the mask. In this way, through the wafer exposure method provided by the present application, in the process of aligning the wafer and the mask, the film thickness of the wafer is no longer limited by the depth of field of the microscope, and the wafer with different film thicknesses can be accurately aligned with the mask, which not only expands the film thickness range that the wafer can be set, but also effectively reduces the manufacturing difficulty of thick film wafers and improves the yield rate.

[0032] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 A schematic diagram of the process of two photographing of a wafer exposure method provided in an embodiment of the present application;

[0035] Figure 2 A schematic diagram of the microscope focus position for two photographs in the wafer exposure method provided in an embodiment of the present application;

[0036] Figure 3 A schematic flow chart of a wafer exposure method provided in an embodiment of the present application.

[0037] Reference numerals:

[0038] 1-mask; 2-wafer; 31-supporting part; 32-moving part; 33-microscope. DETAILED DESCRIPTION

[0039] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0040] The components of the embodiments of the present application generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed, but merely represents the selected embodiments of the present application.

[0041] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0042] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0043] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] Refer to the following Figures 1 to 3 The wafer 2 exposure method and wafer 2 exposure equipment according to some embodiments of the present application are described.

[0045] See also Figures 1 to 3As shown, an embodiment of the first aspect of the present application provides a method for exposing a wafer 2, which is used for an exposure device for a wafer 2. The exposure device for a wafer 2 includes a moving part 32 for adsorbing the wafer 2, a supporting part 31 for placing the mask 1, and a microscope 33, wherein the moving part 32 is arranged on one side of the supporting part 31 in the first direction, and the microscope 33 is arranged on at least one side of the moving part 32 and the supporting part 31 in the first direction.

[0046] Specifically, Figures 1 to 3 As shown, the wafer 2 exposure method comprises the following steps:

[0047] S01 mark, set a first mark on the mask 1 and set a second mark at a corresponding position on the wafer 2.

[0048] Preferably, if Figure 3 As shown, after the above-mentioned marking step, the following steps may be further included: S011 preparation, pre-processing the surface of the wafer 2.

[0049] Optionally, the pretreatment may include cleaning the surface of the wafer 2 .

[0050] Optionally, the pretreatment may further include performing a film forming treatment on the surface of the wafer 2 .

[0051] Preferably, if Figure 3 As shown, after the above-mentioned marking step, the following steps may be further included: S012 coating, in which the coating is performed by rotating the coating on the surface of the wafer 2 .

[0052] It should be noted that in the above S012 coating step, photoresist is coated on the surface of the wafer 2 to prepare for subsequent exposure. During the coating process, the amount of photoresist added and the speed of spin coating need to be controlled to achieve a specified thickness and ensure the uniformity of the photoresist coating.

[0053] Optionally, after the above-mentioned marking step, the following step may be further included: S013 edge removal, to remove excess photoresist from the edge and back side of the wafer 2 .

[0054] Preferably, if Figure 3 As shown, after the above-mentioned marking step, the following steps may be further included: S014 drying, drying the wafer 2 after the coating. Specifically, the wafer 2 is placed in an oven for baking to remove a small amount of solvent remaining in the photoresist, so that the semi-dried photoresist forms a more solid thick film.

[0055] Optionally, the thickness of the thick film in the first direction may be 2 μm to 100 μm.

[0056] S02 pre-alignment, the mask 1 is placed on the supporting part 31, the wafer 2 is placed on the moving part 32, and the moving part 32 is driven by manual observation so that the second mark and the first mark are opposite to each other in the first direction.

[0057] S03 photographs the mask 1, adjusts the microscope 33 so that the microscope 33 focuses on the mask 1, photographs the first mark, and obtains a first image.

[0058] Preferably, if Figure 3 As shown, the above-mentioned wafer 2 exposure method can also include S031 separating the wafer 2 and the mask 1, driving the moving part 32 to move a predetermined distance along the first direction away from the mask 1 to avoid interference between the steps of photographing the mask 1 and photographing the wafer 2.

[0059] Preferably, the predetermined distance may be 10 μm to 100 μm to adapt to the depth of field of the microscope 33 .

[0060] Preferably, if Figure 3 As shown, the above-mentioned wafer 2 exposure method can also include S032 compensating for the equipment error of the moving part 32, and according to the movement error of the moving part 32, reversely translating the moving part 32 to avoid the equipment error of the moving part 32 affecting the alignment accuracy of the wafer 2 and the mask 1 during the process of separating the wafer 2 and the mask 1.

[0061] It should be noted that the movement error of the moving part 32 can be accumulated through multiple movement experiments of the moving part 32 .

[0062] S04 photographs the wafer 2, adjusts the microscope 33 again so that the microscope 33 focuses on the wafer 2, photographs the second mark, and obtains a second image.

[0063] S05 adjusts the offset, obtains the offset of the first mark and the second mark by comparing the first image and the second image, and feeds the offset back to the moving part 32 to adjust the moving part 32 so that the second mark and the first mark under the microscope 33 are opposite to each other in the first direction.

[0064] S06 exposure: using a light source to expose both the wafer 2 and the mask 1.

[0065] Preferably, if Figure 3 As shown, the wafer 2 exposure method may further include S07 development, developing the wafer 2 after exposure.

[0066] According to the wafer 2 exposure method provided by the present application, the microscope 33 is first adjusted to focus on the mask 1 on the supporting part 31 to obtain a clear image of the first mark (i.e., the first image), and then the microscope 33 is adjusted to focus on the wafer 2 on the moving part 32 to obtain a clear image of the second mark (i.e., the second image), and the offset of the first mark and the second mark is obtained by comparing the first image and the second image, and the moving part 32 is adjusted according to the offset, so as to achieve that the second mark under the microscope 33 and the first mark are directly opposite to each other in the first direction, so as to complete the alignment of the wafer 2 and the mask 1. In this way, through the wafer 2 exposure method provided by the present application, in the process of aligning the wafer 2 and the mask 1, the film thickness of the wafer 2 is no longer limited by the depth of field of the microscope 33, and the wafer 2 with different film thicknesses can be accurately aligned with the mask 1, which not only expands the film thickness range that the wafer 2 can be set, but also effectively reduces the manufacturing difficulty of the thick film wafer 2 and improves the yield rate.

[0067] like Figure 1 As shown, the left side of the figure shows the relative positions of the wafer 2 exposure equipment placing the mask 1 and the wafer 2 after the S01 marking step, the S02 pre-alignment step and the S05 offset adjustment step from top to bottom, and the right side of the figure shows the relative states of the first mark and the second mark at the corresponding positions. Figure 2 As shown, the left side of the figure shows the focusing position of the microscope 33 in the step S03 of photographing the mask 1, and the right side of the figure shows the focusing position of the microscope 33 in the step S04 of photographing the wafer 2.

[0068] In an embodiment, Figure 1 As shown, the first mark is a through hole penetrating the mask 1 along the first direction, and the second mark is a mark set on the surface of the wafer 2, and the shape of the mark is adapted to the shape of the through hole.

[0069] Preferably, if Figure 1 As shown, the through hole and the mark are both in a "cross" shape, so as to facilitate the positioning of the wafer 2 and the mask 1 in the X-axis direction and the Y-axis direction. It should be noted that, in terms of a rectangular coordinate system, the first direction can be a Z-axis direction perpendicular to both the X-axis direction and the Y-axis direction.

[0070] However, it is not limited to this, as long as the wafer 2 and the mask 1 can be accurately positioned, the shapes of the through hole and the mark are not limited to a "cross" shape, but can also be other shapes, such as polygons, multi-pointed stars or other special shapes.

[0071] See also Figure 1 and Figure 2The embodiment of the second aspect of the present application also provides a wafer 2 exposure device, including the wafer 2 exposure method described in any of the above embodiments, and thus has all the beneficial technical effects of the wafer 2 exposure method, which will not be repeated here.

[0072] Specifically, the wafer 2 exposure device includes the above-mentioned supporting part 31 , the moving part 32 and the microscope 33 .

[0073] Optionally, the supporting portion 31 may be a stage of a microscope 33 .

[0074] Optionally, the moving part 32 may be a wafer 2 transfer table.

[0075] Optionally, the microscope 33 may include a collection lens and a lifting part connected to each other, and the lifting part can drive the collection lens to move along a first direction, so that the microscope 33 can adjust the focal position along the first direction, thereby realizing two separate focusing collections of the first mark and the second mark.

[0076] It should be noted that the supporting part 31 , the moving part 32 and the microscope 33 are all existing products in the art, and their specific structures and assembly relationships are not described in detail here.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A wafer exposure method, characterized in that: Used in a wafer exposure device, the wafer exposure device comprises a moving part for adsorbing a wafer, a supporting part for placing a mask, and a microscope, the moving part is arranged on one side of the supporting part in a first direction, and the microscope is arranged on at least one side of the moving part and the supporting part in the first direction; The wafer exposure method comprises the following steps: Marking, setting a first mark on the mask and setting a second mark at a corresponding position on the wafer; Pre-alignment, placing the mask on the supporting part, placing the wafer on the moving part, and driving the moving part through manual observation so that the second mark and the first mark are aligned with each other in the first direction; photographing the mask, adjusting the microscope so that the microscope focuses on the mask, photographing the first mark, and acquiring a first image; photographing the wafer, adjusting the microscope again so that the microscope focuses on the wafer, photographing the second mark, and acquiring a second image; Adjusting the offset, obtaining the offset of the first mark and the second mark by comparing the first image and the second image, and feeding back the offset to the moving part to adjust the moving part so that the second mark and the first mark under the microscope are directly opposite to each other in the first direction; Exposure: using a light source to expose both the wafer and the mask.

2. The wafer exposure method according to claim 1, characterized in that: Between the steps of photographing the mask and photographing the wafer, the following steps are also included: The wafer and the mask are separated, and the moving part is driven to move a predetermined distance along the first direction in a direction away from the mask.

3. The wafer exposure method according to claim 2, characterized in that: After the step of separating the wafer and the mask, the method further includes: The device error of the moving part is compensated, and the moving part is translated in the opposite direction according to the movement error of the moving part.

4. The wafer exposure method according to claim 2, characterized in that: The predetermined distance is 10 μm to 100 μm.

5. The wafer exposure method according to any one of claims 1 to 4, characterized in that: After the marking step, the method further includes: Preparation: Pre-treat the wafer surface.

6. The wafer exposure method according to claim 5, characterized in that: The preparation step also includes: Glue coating, performing spin coating on the surface of the wafer; Drying: Drying the wafer after the glue coating.

7. The wafer exposure method according to any one of claims 1 to 4, characterized in that: After the exposure step, the method further comprises: Development: Develop the exposed wafer.

8. The wafer exposure method according to claim 1, characterized in that: The first mark is a through hole penetrating the mask along the first direction; The second mark is a mark set on the surface of the wafer, and the shape of the mark is adapted to the shape of the through hole.

9. The wafer exposure method according to claim 8, characterized in that: Both the through hole and the mark are in a cross shape.

10. A wafer exposure device, characterized in that: A wafer exposure method using any one of claims 1 to 9; The wafer exposure equipment includes the moving part, the supporting part and the microscope.

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