Standard mirror unit, standard mirror mounting assembly and wafer detection device

Abstract

The present application provides a standard mirror unit, a standard mirror mounting assembly, and a wafer detection device, wherein the standard mirror unit includes a standard mirror and at least two protrusions, wherein the at least two protrusions are fixed on the outer peripheral surface of the standard mirror and are arranged at intervals along the circumferential direction. The technical solution provided by the present application is to arrange protrusions on the outer peripheral surface of the standard mirror, and to install the standard mirror by means of the protrusions, so that a small gap can be formed between the two standard mirrors after installation. When an object to be detected, such as a wafer, is located between the two standard mirrors for detection, the wafer is not easy to vibrate due to the large air resistance in the small gap, which is conducive to improving the detection accuracy of the wafer.

Description

Technical Field

[0001] The present application relates to the field of optical technology, and in particular to a standard mirror unit, a standard mirror mounting assembly and a wafer detection device. Background Art

[0002] Wafer refers to silicon wafer, which is the substrate used to manufacture semiconductor devices. Through a series of semiconductor manufacturing processes, wafers can be made into chips.

[0003] In the manufacturing process, it is usually necessary to measure the relevant parameters of the wafer, such as thickness, flatness or warpage. One existing technology uses an interferometer-based wafer detection device to detect the relevant parameters of the wafer. However, since the wafer is easily affected by air and vibrates during the detection process, the accuracy of the measurement result is difficult to guarantee.

[0004] Therefore, it is necessary to provide a new technical solution to reduce or avoid the vibration of the wafer during the detection process and improve the detection accuracy of the wafer. Summary of the invention

[0005] In view of this, the present application provides a standard mirror unit, a standard mirror mounting assembly and a wafer inspection device to solve the problem in the prior art that the wafer is prone to vibrate during the inspection process and thus affects the inspection results.

[0006] In order to achieve the above-mentioned object, the present application provides a standard mirror unit, which includes a standard mirror and at least two protrusions, wherein the at least two protrusions are fixed on the outer circumferential surface of the standard mirror and are arranged at intervals along the circumferential direction.

[0007] Optionally, three protrusions are provided, and the three protrusions are evenly spaced apart along the circumference of the circular standard mirror.

[0008] Optionally, each of the protrusions is adhered to the outer peripheral surface of the standard mirror.

[0009] According to another aspect of the present application, a standard mirror mounting assembly is further provided, the standard mirror mounting assembly comprising the standard mirror unit as described above and a frame for mounting the standard mirror unit;

[0010] Wherein, the protrusion of the standard mirror unit is connected to the frame.

[0011] Optionally, the protrusion is connected to the frame via an elastic connecting piece.

[0012] Optionally, a piezoelectric ceramic for adjusting the position of the standard mirror unit relative to the frame is further arranged between the protrusion and the frame.

[0013] Optionally, the frame comprises an annular structure having a cavity, the protrusion of the standard mirror unit is connected to an inner side wall of the annular structure, and one side surface of the standard mirror protrudes from the frame.

[0014] In another aspect of the present application, a wafer inspection device is further provided, the wafer inspection device comprising two interferometers, each of the interferometers comprising the standard mirror mounting assembly as described above;

[0015] The standard mirror mounting assemblies of the two interferometers are placed opposite to each other, and a gap for placing a wafer to be inspected is formed between the standard mirrors of the two standard mirror mounting assemblies.

[0016] Optionally, the width of the gap is 2-6 mm.

[0017] Optionally, the wafer inspection device further includes a carrying component for carrying the wafer to be inspected;

[0018] The bearing component is arranged to enter the gap between the two standard mirror mounting assemblies along the vertical direction;

[0019] Alternatively, the bearing component is arranged at a preset position, and the two standard mirror mounting assemblies are respectively moved from both sides of the bearing component toward the bearing component until there is a preset gap between them and the bearing component.

[0020] Through the technical solution provided in the present application, by setting a bump on the standard mirror, the standard mirror can be installed using the bump, and the bump on the outer surface will not affect the two standard mirrors from being close to each other, so that the two standard mirrors can have a smaller gap after installation. When the object to be measured (such as a wafer) is located between the two standard mirrors 1 for inspection, the wafer is not easy to vibrate due to the larger air resistance in the smaller gap, which is beneficial to improving the inspection accuracy of the wafer.

[0021] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of this application are used to provide a further understanding of this application. The illustrative implementation methods and descriptions of this application are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0023] Figure 1 is a schematic structural diagram of a standard mirror unit according to one embodiment of the present application;

[0024] Figure 2 It is a structural schematic diagram of a standard mirror mounting assembly according to one embodiment of the present application;

[0025] Figure 3It is a schematic diagram of the structure of two standard mirror mounting components being placed relative to each other;

[0026] Figure 4 It is a schematic diagram of the structure of two standard mirror mounting components (after removing the frame) placed relative to each other;

[0027] Figure 5 A schematic diagram of the structure of a wafer inspection device according to one embodiment of the present application;

[0028] Figure 6 Schematic diagram of the structure of a wafer inspection device according to another embodiment of the present application.

[0029] Description of Reference Numerals

[0030] 1-standard mirror; 2-bump; 3-piezoelectric ceramic; 4-elastic connector; 5-frame; 10-standard mirror mounting assembly; 20-collimator; 30-beam splitter; 40-camera; 50-relay lens; 60-light source; 70-wafer. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0032] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships 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 a limitation on the present application. In addition, "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0034] When testing the two side surfaces of the wafer, the wafer is placed between the two standard mirrors of the detection device, and the wafer surface is tested through the interference ripples generated by the interference of the light reflected by the standard mirrors on the corresponding sides of the wafer. When the distance between the two standard mirrors is large, the wafer is prone to vibrate due to the influence of air, affecting the test results. The standard mirror can be installed by clamping when in use, but the clamping structure will cause a certain distance between the two standard mirrors, so the problem of wafer vibration affected by air is difficult to solve.

[0035] To this end, the present application provides a standard mirror unit, such as Figure 1 As shown, the standard mirror unit includes a standard mirror (Transmission Flat, TF) 1 and at least two protrusions 2. The at least two protrusions 2 are fixed on the outer circumferential surface of the standard mirror 1 and are arranged at intervals along the circumferential direction.

[0036] Preferably, three protrusions 2 are evenly spaced apart along the circumference of the standard mirror 1 .

[0037] Preferably, the bump 2 can be glued to the outer peripheral surface of the standard mirror 1, wherein the bump 2 is made of a material having an expansion coefficient consistent with that of the standard mirror 1, so that the bump 2 will not separate from the standard mirror 1 due to thermal expansion and contraction.

[0038] The technical solution provided by the present application is to arrange a protrusion 2 on the standard mirror 1, and the protrusion 2 can be used to install the standard mirror 1, such as Figure 2 The standard mirror 1 shown is mounted on the frame 5 by means of a protrusion 2. This can overcome the problem in the prior art that the standard mirror 1 is installed by clamping the standard mirror 1 (due to the thickness of the clamping structure), which causes the two standard mirrors 1 to be unable to get too close, so that the gap between the two standard mirrors 1 is large, causing the wafer (or other objects to be measured) to be easily affected by the air and vibrate. In the present application, the standard mirror 1 is installed by means of a protrusion 2, and the protrusion 2 will not affect the distance between the two standard mirrors 1 and the distance between them, so that the two standard mirrors 1 can have a smaller gap after installation, for example, 2-6mm, so that when the wafer is located between the two standard mirrors 1 for detection, the wafer is not easy to vibrate due to the larger air resistance in the smaller gap. In particular, when the distance between the two standard mirrors 1 is 2mm, when a wafer with a thickness of 0.6-0.8mm is placed in the gap, the gap between the wafer and the standard mirror 1 is only 0.6-0.7mm, and the wafer to be detected will be very stable and not easy to vibrate, which is conducive to improving the detection accuracy of the wafer.

[0039] Of course, it is understandable that the object to be tested using the standard mirror unit in the present application is not limited to wafers, and other objects that require surface testing may also be tested.

[0040] According to another aspect of the present application, a standard mirror mounting assembly is also provided, such as Figure 2 and Figure 3 As shown, the standard mirror mounting assembly 10 comprises the standard mirror unit as described above and a frame 5 for mounting the standard mirror unit; wherein the protrusion 2 of the standard mirror unit is connected to the frame 5 .

[0041] In one embodiment, the protrusion 2 and the frame 5 are connected via an elastic connecting member 4 .

[0042] Specifically, one end of the elastic connector 4 can be connected to the protrusion 2 by bolts or other connecting methods, and the other end can be connected to the frame 5 by bolts or other connecting methods. The elastic connector 4 can be an elastic sheet or other elastic structures.

[0043] In this embodiment, a piezoelectric ceramic 3 for adjusting the position of the standard mirror unit relative to the frame 5 is also provided between each bump 2 and the frame 5. Figure 2 and Figure 3 As shown, one end of the piezoelectric ceramic 3 is connected to the frame 5, and the other end is connected to the bump 2. Figure 4 The schematic diagram shows that one end of the piezoelectric ceramic 3 is connected to the bump 2. According to the piezoelectric characteristics of the piezoelectric ceramic, when a voltage is applied to the piezoelectric ceramic 3, the piezoelectric ceramic 3 will be deformed, so that the relative position of the bump 2 with respect to the frame 2 can be adjusted.

[0044] In the technical solution provided by the present application, by setting the piezoelectric ceramic 3, the wafer detection device (such as a Sophie interferometer or other interferometer) having the standard mirror mounting assembly 10 can be phase-shifted, and when two standard mirror mounting assemblies 10 are arranged relative to each other (such as Figure 3 The parallelism of the standard mirrors 1 of the two standard mirror mounting assemblies 10 can be adjusted by the piezoelectric ceramics 3 .

[0045] The frame 5 comprises an annular structure with a cavity, such as Figure 2 As shown, the frame 5 in this embodiment is a circular ring structure, and of course, it can be set to various structural forms as needed. The protrusion 2 of the standard mirror unit is connected to the inner side wall of the ring structure, and one side surface of the standard mirror 1 protrudes from the frame 5. In this way, when two standard mirror mounting assemblies 10 are arranged, Figure 3 As described above, the standard mirrors 1 protrude from one side of the frame 5 and are arranged toward each other, and the two standard mirrors 1 can be close to each other until the gap between them is only 2-6 mm without being interfered by the installation structure.

[0046] According to another aspect of the present application, there is also provided a wafer inspection device, the wafer inspection device comprising two interferometers, each interferometer comprising the standard mirror mounting assembly 10 as described above;

[0047] The two standard mirror mounting assemblies 10 of the interferometer are placed opposite to each other, and a gap for placing the wafer 70 to be inspected is formed between the standard mirrors 1 of the two standard mirror mounting assemblies 10 .

[0048] like Figure 5 As shown, the portion within the dotted frame is one of the interferometers, which is a Sophie interferometer. Each Sophie interferometer includes: a standard mirror mounting assembly 10, a collimator 20, a beam splitter 30, a camera 40, a relay lens 50 and a light source 60 (such as an illumination lamp).

[0049] When using the wafer inspection device, two Sophie interferometers are placed opposite to each other, the standard mirrors 1 of the standard mirror mounting assemblies 10 of the two interferometers are parallel and have a preset gap, and the wafer 70 to be inspected is placed vertically between the two parallel standard mirrors 1. Then, the parameters on both sides of the wafer 70 can be inspected by the two Sophie interferometers. The detection principle of the wafer inspection device is not the focus of this application and is a common technology of technicians in this field, which will not be repeated here.

[0050] Preferably, the width of the gap between the standard mirrors 1 of the standard mirror mounting assemblies 10 of the two interferometers is 2-6 mm, and more preferably, the gap is 2-4 mm.

[0051] The wafer 70 to be inspected is placed in the gap for inspection. Since the gap between the wafer 70 and the standard mirror of the standard mirror mounting assembly 10 is very small and the air resistance is very large (the smaller the gap, the greater the air resistance), the wafer 70 has good stability and is not prone to vibration, which can help improve the accuracy of wafer inspection.

[0052] In another embodiment, a wafer inspection device is provided, which also includes two interferometers, and the two interferometers are arranged opposite to each other. Figure 6 As shown, each interferometer includes the standard mirror mounting assembly 10, the collimator 20, the beam splitter 30 and the camera 40 of the present application. Different from the above-mentioned embodiment, the interferometer also includes an optical path folding assembly (including a first reflector M1 and a second reflector M2) for folding the optical path between the collimator 20 and the beam splitter 30. By folding the first reflector M1 and the second reflector M2, the optical path between the collimator 20 and the beam splitter 30 is folded to reduce the amount of space occupied by the optical path between the beam splitter 30 and the collimator 20.

[0053] The wafer to be inspected is placed between two standard mirror mounting assemblies 10 of the interferometers that are placed opposite to each other, and parameters on both sides of the wafer can be inspected.

[0054] Likewise, in this embodiment, the width of the gap between the standard mirrors 1 of the standard mirror mounting assemblies 10 of the two interferometers is preferably 2-6 mm, and more preferably, the gap is 2-4 mm.

[0055] In this embodiment, at least the standard mirror mounting assembly 10, the collimator 20, and the first reflector M1 and the second reflector M2 of the interferometer are placed in a shockproof isolation box to avoid the influence of the outside world on the detection result.

[0056] The wafer inspection device further includes a bearing component (not shown) for bearing the wafer 70 to be inspected. The wafer 70 is fixed on the bearing component, and then the bearing component is set on two standard mirror mounting assemblies 10 for inspection.

[0057] In one embodiment, if Figure 6 In the embodiment shown, the bearing member is arranged to extend in the vertical direction ( Figure 6 The X direction shown) enters the gap between the standard mirror mounting assemblies 10 of the two interferometers;

[0058] In another embodiment, the bearing component may be arranged at a preset position, and two standard mirror mounting assemblies 10 are respectively moved from both sides of the bearing component toward the bearing component until there is a preset gap between the bearing component and the two standard mirror mounting assemblies 10 .

[0059] The wafer detection device provided by the present application can effectively prevent the wafer from vibrating during the detection process and improve the accuracy of wafer detection. The wafer detection device is particularly suitable for detecting large-sized wafers that are more likely to vibrate.

[0060] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A standard mirror unit, characterized in that: The standard mirror unit includes a standard mirror and at least two protrusions, wherein the at least two protrusions are fixed on the outer circumferential surface of the standard mirror and are arranged at intervals along the circumferential direction to install the standard mirror. The standard mirror unit is one of two standard mirror units arranged opposite to each other in a wafer detection device, and the wafer detection device is used to detect a wafer arranged between the two standard mirror units. The at least two protrusions are used to install the standard mirror on a frame corresponding to the standard mirror in the wafer detection device. The two frames of the two oppositely arranged standard mirror units are arranged far apart, and the two standard mirrors are arranged opposite to each other so that there is no interference of the installation structure between the two standard mirrors.

2. The standard mirror unit according to claim 1, characterized in that: There are three protrusions, and the three protrusions are evenly spaced along the circumference of the circular standard mirror.

3. The standard mirror unit according to claim 1 or 2, characterized in that: Each of the protrusions is adhered to the outer peripheral surface of the standard mirror.

4. A standard mirror mounting assembly, characterized in that: The standard mirror mounting assembly is one of two relatively arranged standard mirror mounting assemblies in a wafer detection device, the wafer detection device is used to detect a wafer arranged between the two standard mirror mounting assemblies, the standard mirror mounting assembly comprises a standard mirror unit according to any one of claims 1 to 3 and the frame for mounting the standard mirror unit, the two frames of the relatively arranged two standard mirror mounting assemblies are arranged far apart, and the two standard mirrors are arranged relatively, so that there is no interference of mounting structures between the two standard mirrors; Wherein, the protrusion of the standard mirror unit is connected to the frame.

5. The standard mirror mounting assembly according to claim 4, characterized in that: The protrusion is connected to the frame via an elastic connecting piece.

6. The standard mirror mounting assembly according to claim 5, characterized in that: A piezoelectric ceramic for adjusting the position of the standard mirror unit relative to the frame is also arranged between the protrusion and the frame.

7. The standard mirror mounting assembly according to any one of claims 4 to 6, characterized in that: The frame comprises an annular structure with a cavity, the protrusion of the standard mirror unit is connected to the inner side wall of the annular structure, and one side surface of the standard mirror protrudes from the frame.

8. A wafer inspection device, characterized in that: The wafer detection device comprises two interferometers, each of which comprises a standard mirror mounting assembly according to any one of claims 4 to 7; The standard mirror mounting assemblies of the two interferometers are placed opposite to each other, and a gap for placing a wafer to be inspected is formed between the standard mirrors of the two standard mirror mounting assemblies.

9. The wafer inspection device according to claim 8, characterized in that: The width of the gap is 2-6 mm.

10. The wafer inspection device according to claim 8 or 9, characterized in that: The wafer inspection device also includes a carrying component for carrying the wafer to be inspected; The bearing component is arranged to enter the gap between the two standard mirror mounting assemblies along the vertical direction; Alternatively, the bearing component is arranged at a preset position, and the two standard mirror mounting assemblies are respectively moved from both sides of the bearing component toward the bearing component until there is a preset gap between them and the bearing component.

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