CN220795032U

CN220795032U - Wafer detecting device

Info

Publication number: CN220795032U
Application number: CN202321722887.6U
Authority: CN
Inventors: 李刚; 许平康; 袁纯真
Original assignee: GTA Semiconductor Co Ltd
Current assignee: GTA Semiconductor Co Ltd
Priority date: 2023-07-03
Filing date: 2023-07-03
Publication date: 2024-04-16
Anticipated expiration: 2033-07-03

Abstract

The application provides a wafer detection device, the wafer detection device includes base, light source, sensitization device, and data processing unit. The base is used for placing a wafer; the light source is arranged above the base and irradiates the wafer; the photosensitive device is arranged above the base and used for collecting reflected light information on the surface of the wafer; the data processing unit is communicated with the photosensitive device, and acquires and analyzes the reflected light information acquired by the photosensitive device to judge whether the wafer has hidden injury with fragmentation risk. The wafer detection device can detect the wafer with the hidden damage of the cracking risk, so that the wafer with the hidden damage is prevented from entering the process machine, further damage to the wafer by the subsequent process is effectively prevented until the wafer is cracked, the influence of the cracked wafer on the machine is reduced, the machine productivity is improved, and the production cost is reduced.

Description

Wafer detecting device

Technical Field

The present application relates to the field of semiconductors, and more particularly, to a wafer inspection apparatus.

Background

The thinning of the back of the wafer is to grind the back matrix material of the wafer with a certain thickness and remove the matrix material. After the wafer is thinned, the chip generated by the method has the following advantages: 1. the heat dissipation efficiency is obviously improved, and the thin chip is more beneficial to leading out heat from the substrate, so that the performance of the chip is improved and the service life of the chip is prolonged; 2. the packaging volume is reduced, the chip volume is correspondingly reduced due to the reduction of the thickness, and the requirements of increasingly developing microelectronic products in the direction of light weight, thinness and shortness are met; 3. the internal stress of the chip is reduced, heat is generated in the working process of the chip, the thinner the chip is, the smaller the thermal difference between the substrate layers is, and the chip is prevented from being broken due to larger internal stress; 4. the electrical performance is improved, the thinner the thickness of the wafer is, the closer the back surface is plated with gold to enable the ground plane to be, and the better the high-frequency performance of the generated chip is; 5. the scribing processing yield is improved, the processing amount of packaging scribing can be reduced after the wafer is thinned, the defects of edge breakage, corner breakage and the like in scribing are avoided, and the generated chip breakage probability is reduced.

However, for power devices, the wafer strength may be reduced after the backside thinning process, resulting in chipping of the wafer as it enters the subsequent processing tools. If the wafer is cracked in the main process cavity of the machine, the cracked wafer can damage the process environment of the machine and damage machine components, so that the machine alarms; if the wafer is cracked in the acid tank cleaning machine, the cracked wafer can pollute the acid tank, so that the acid tank needs to be replaced by new acid liquid. In addition, after the wafer with the hidden crack abnormality is loaded on the wafer mounting machine table, even if the wafer is not cracked, the gas ring is too large due to the unfilled corner or hidden crack at the edge of the wafer, the next process cannot be performed, and after the wafer is processed, an ultraviolet irradiation adhesive tape (also called as a UV film) is mounted on the mounting machine table, so that excessive loss of the UV film is caused. If the wafer itself has a hidden crack but is not found before entering the mounter table, further damage may be caused to the hidden crack wafer during the vacuum suction process of the mounter table.

Wafers with hidden damages caused by fragmentation risks not only affect the productivity of normal operation of the machine, but also affect the failure and replacement of machine components and the loss of machine consumables, thereby affecting the service life of the whole machine and increasing the production cost.

Therefore, the wafer inspection device can find the hidden damage of the wafer in advance and provide early warning, which is very valuable for improving the productivity of the machine and reducing the production cost.

Disclosure of Invention

The technical problem to be solved by the application is to provide a wafer detection device which can detect and discover wafer abnormality in advance and provide early warning.

In order to solve the above-mentioned problem, the present application provides a wafer inspection apparatus, including: a susceptor for placing a wafer; the light source is arranged above the base and used for irradiating the surface of the wafer; the photosensitive device is arranged above the base and is used for collecting reflected light information on the surface of the wafer; and the data processing unit is communicated with the photosensitive device and is used for acquiring and analyzing the reflected light information acquired by the photosensitive device so as to judge whether the wafer has hidden injury with the risk of fragmentation.

In some embodiments, the data processing unit is further to: setting a standard threshold value of the intensity of the reflected light; and triggering an alarm when the light intensity value in the reflected light information exceeds the light intensity standard threshold.

In some embodiments, the data processing unit is further to: establishing a standard model for reflected light information of a standard wafer; comparing the standard model with the obtained reflected light information, and locking the wafer defect through analysis and calculation.

In some embodiments, the light source irradiates different portions of the wafer surface at the same angle.

In some embodiments, the light source irradiates different portions of the wafer surface at different angles.

In some embodiments, the light source is movable in position to illuminate the wafer surface at multiple angles.

In some embodiments, the light source is multiple to illuminate the wafer surface simultaneously in multiple directions.

In some embodiments, the photosensitive devices are multiple, and the reflected light information of the wafer surface is collected at multiple different angles.

In some embodiments, the susceptor is rotatable to rotate the wafer.

In some embodiments, the light source is an infrared light source and the light sensing device is an infrared camera.

According to the technical scheme, through analyzing the reflected light information of the light source irradiated to the surface of the wafer, the possible abnormality of micro hidden cracks, unfilled corners, pits and the like of the wafer is detected, and early warning is carried out in advance, so that the wafer is prevented from being cracked after entering a process machine, the influence of the cracked wafer on the machine environment and components is avoided, the machine productivity is improved, and the machine maintenance cost is reduced.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following description will briefly explain the drawings needed in the embodiments of the present application, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of a wafer inspection apparatus according to a first embodiment of the present application;

FIG. 2 is a schematic diagram of a wafer inspection apparatus according to a second embodiment of the present disclosure;

FIG. 3 is a schematic view of a wafer inspection apparatus according to a third embodiment of the present disclosure;

fig. 4 is a schematic view of a wafer inspection apparatus according to a fourth embodiment of the present disclosure;

fig. 5 is a schematic view of a wafer inspection apparatus according to a fifth embodiment of the present disclosure;

fig. 6 is a schematic diagram of a wafer inspection apparatus according to a sixth embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.

Fig. 1 is a schematic diagram of a wafer inspection apparatus according to a first embodiment of the present application. Referring to fig. 1, the wafer inspection apparatus includes: a base 101, a light source 103, a photosensitive device 104, and a data processing unit 105. The wafer inspection apparatus is used to inspect whether the wafer 102 has a hidden damage that is at risk of chipping. In this embodiment, the wafer 102 is placed in the center of the susceptor 101, the light source 103 and the photosensitive device 104 are both disposed above the susceptor 101, and the photosensitive device 104 communicates with the data processing unit 105. The light beam emitted from the light source 103 irradiates the surface of the wafer 102 at an angle, and the photosensitive device 104 collects the reflected light information of the surface of the wafer 102 and transmits the result to the data processing unit 105. The data processing unit 105 acquires and analyzes the reflected light information to determine whether the wafer has a hidden injury that is at risk of chipping.

In this embodiment, the light source 103 and the light sensing device 104 have a certain distance between the front projections on the base 101, i.e. they do not overlap.

Specifically, the light source 103 irradiates the surface of the wafer 102 with the detection light, and the irradiation may be performed by irradiating all of the wafer 102 at once or by scanning stepwise irradiation. The light source used may be visible light or infrared light. The angles of illumination may be set to the same angle or to different angles. The light source 103 irradiates the surface of the wafer 102 with abnormal shapes such as hidden cracks, unfilled corners, pits and the like, and the reflected light information index collected by the photosensitive device 104 is abnormal. For the wafer 102 with these problems, the apparatus of this embodiment can early warn in advance, so as to avoid the wafer 102 from being cracked after entering the process machine, thereby avoiding the impact of the cracked wafer on the machine environment and components, improving the machine productivity, and reducing the machine maintenance cost.

In some embodiments, the photosensitive device 104 may be a camera or a similar photographing device, and the light source 103 is followed to obtain the entire topography of the surface of the wafer 102 at one time, or step-wise obtain the reflected image and splice with software. After the reflected image is obtained, by analyzing the reflected light information of the surface of the wafer 102 irradiated by the light source 103, the possible abnormalities such as fine hidden cracks, unfilled corners, pits, etc. of the wafer 102 are detected.

In some embodiments, the standard threshold is determined by experimentally measuring the intensity values of light in the reflected light information from different areas of the surface of a large number of standard wafers illuminated by the same light source, and determining the intensity range of the reflected light from the surface of the wafer without a hidden injury based on the measurement results. When the data processing unit 105 processes the reflected light information on the surface of the wafer 102, an alarm is triggered when the light intensity value in the reflected light information exceeds the normal range of the light intensity obtained by the experiment. The field personnel inform the process engineers of the corresponding machine to process, thereby effectively preventing the wafer with hidden injury from entering the machine and jeopardizing the normal work and operation condition of the machine.

In some embodiments, modeling is performed on numerical values such as light intensity, angle and position coordinates in reflected light information of different areas when a large number of standard wafer surfaces are irradiated by the same light source through experiments, so as to obtain a standard model of reflected light of the normal wafer surfaces; substituting the collected reflected light information on the surface of the wafer 102 into the standard model, and locking the wafer defects such as hidden cracks, unfilled corners and pits through analysis and calculation.

In this embodiment, the included angle between the light beam emitted by the light source 103 and the plane of the base 101 is controllable, and the sliced area on the surface of the wafer 102 is irradiated at different angles, so as to complete the complete irradiation of the wafer 102, the angle of the photosensitive device 104 is unchanged, and each irradiation acquires the reflected light information on the surface of the wafer 102.

In some embodiments, the photosensitive device 104 collects the reflected light information of the surface of the wafer 102 at different angles multiple times, so that the reflected light information collection is more complete.

In some embodiments, the included angle between the light beam emitted by the light source 103 and the plane of the base 101 is fixed, and the complete irradiation of the wafer 102 is completed by moving the light source 103.

Fig. 2 is a schematic diagram of a wafer inspection apparatus according to a second embodiment of the present application. Referring to fig. 2, the wafer inspection apparatus includes: the susceptor 101, the light source 203, the photosensitive device 104, and the data processing unit 105 are used for inspecting the wafer 102. The wafer 102 is placed in the center of the base 101, the light source 203 is disposed above the base 101 through a slide rail 206, the photosensitive device 104 is disposed above the base 101, and the photosensitive device 104 communicates with the data processing unit 105. The photosensitive device 104 collects information of the reflected light on the surface of the wafer 102 and transmits the result to the data processing unit 105. The data processing unit 105 acquires and analyzes the reflected light information to determine whether the wafer has a hidden injury that is at risk of chipping.

In this embodiment, the light source 203 is a movable light source, and a slide rail 206 or a similar mechanism capable of moving is disposed above the light source 203, so that the light source 203 can move above the wafer 102, thereby realizing multi-directional and multi-angle irradiation of the wafer 102. In the position where the abnormal morphology such as the hidden crack, the unfilled corner, the pit, etc. exists, the reflected light of the wafer 102 may be abnormally enhanced or reduced. However, it is possible that the abnormal shapes such as the hidden crack, the unfilled corner, the pit and the like are only sensitive to the light rays at a certain angle, so that the sliding rail 206 or a similar mechanism capable of playing a role in moving is arranged, multi-angle irradiation of the wafer 102 can be realized, the omission ratio is reduced, and the detection precision is improved.

Fig. 3 is a schematic diagram of a wafer inspection apparatus according to a third embodiment of the present application. Referring to fig. 3, the wafer inspection apparatus includes: the susceptor 101, the light sources 303a and 303b, the photosensitive device 104, and the data processing unit 105 are used to inspect the wafer 102. The wafer 102 is placed in the center of the base 101, the light sources 303a, 303b and the photosensitive device 104 are disposed above the base 101, and the photosensitive device 104 communicates with the data processing unit 105. The photosensitive device 104 collects information of the reflected light on the surface of the wafer 102 and transmits the result to the data processing unit 105. The data processing unit 105 acquires and analyzes the reflected light information to determine whether the wafer has a hidden injury that is at risk of chipping.

The number of light sources is plural in the present embodiment, and the light sources 303a and 303b are exemplified in the present embodiment. In other embodiments, more light sources may be included, which may be combined to illuminate the wafer 102 from multiple angles. By arranging the slide rail 206 or a similar mechanism capable of moving above the light sources 303a and 303b, the light sources 203a and 303b can move above the wafer 102, so as to irradiate the wafer 102 in multiple directions and multiple angles. The omission ratio is reduced, and the detection precision is improved.

Fig. 4 is a schematic diagram of a wafer inspection apparatus according to a fourth embodiment of the present application. Referring to fig. 4, the wafer inspection apparatus includes: the wafer 102 is inspected by the susceptor 101, the light source 103, the photosensitive devices 404a and 404b, and the data processing unit 105. The wafer 102 is placed in the center of the susceptor 101, the light source 103 and the photosensitive devices 404a and 404b are disposed above the susceptor 101, and the photosensitive devices 404a, 404b are in communication with the data processing unit 105. The photosensitive devices 404a and 404b collect reflected light information from the surface of the wafer 102 and transmit the result to the data processing unit 105. The data processing unit 105 acquires and analyzes the reflected light information to determine whether the wafer has a hidden injury that is at risk of chipping.

In this embodiment, a plurality of photosensitive devices are provided, and in this embodiment, the photosensitive devices 404a and 404b are exemplified, and two of the photosensitive devices are disposed at different positions above the base 101 and communicate with the data processing unit 105. When the light beam emitted by the light source 103 irradiates the surface of the wafer 102, the two photosensitive devices 404a and 404b collect reflected light information with different angles in different directions, and the reflected light information and the positional relationship between the photosensitive device 404a or 404b and the wafer 102 are transferred to the data processing unit 105, so that the integrity of the collection of the reflected light information is improved, and the omission factor is reduced.

Fig. 5 is a schematic diagram of a wafer inspection apparatus according to a fifth embodiment of the present application. Referring to fig. 5, the wafer inspection apparatus includes: the susceptor 101, the light source 103, the photosensitive device 104, and the data processing unit 105 are used for inspecting the wafer 102. The wafer 102 is placed in the center of the susceptor 101, the light source 103 and the photosensitive device 104 are disposed above the susceptor 101, and the photosensitive device 104 communicates with the data processing unit 105. The photosensitive device 104 collects information of the reflected light on the surface of the wafer 102 and transmits the result to the data processing unit 105. The data processing unit 105 acquires and analyzes the reflected light information to determine whether the wafer has a hidden injury that is at risk of chipping.

In the present embodiment, the base 401 is provided rotatably. By providing a rotating structure 507 below the base 401, the optical wafer 102 can rotate relative to the light source 103, and multi-azimuth and multi-angle irradiation of the wafer 102 can be realized.

In some embodiments, the light source is an infrared light source and the light sensing device is an infrared camera. Fig. 6 is a schematic diagram of a wafer inspection apparatus according to a sixth embodiment of the present application, where the wafer inspection apparatus includes: the susceptor 101, the infrared light source 603, the infrared camera 604, and the data processing unit 105 are used to inspect the wafer 102. The wafer 102 is placed in the center of the susceptor 101, the external light source 603 and the infrared camera 604 are disposed above the susceptor 101, and the photosensitive device 104 communicates with the data processing unit 105. An infrared light source 303 and an infrared camera 304 are disposed above the base 101 in the wafer inspection apparatus. The infrared camera 604 communicates with the data processing unit 105 via a network. After receiving the infrared image information obtained by the infrared camera 604, the data processing unit 105 compares the infrared image information of the same angle of the standard wafer, and screens the hidden defect of the wafer 102.

In some embodiments, a large amount of reflected light information data obtained by irradiating the surfaces of different areas of a normal wafer and an abnormal wafer with different light rays is classified and learned for artificial intelligence, so that the artificial intelligence obtains discrimination capability through learning, the image information characteristics of different wafers are identified, and the hidden defects of the wafers are accurately found.

According to the above technical scheme, by analyzing the information of the reflected light irradiated by the light source 103 to the surface of the wafer 102, the possible abnormalities of the wafer 102 such as fine hidden cracks, unfilled corners, pits and the like are detected and early warned in advance. The wafer with internal hidden cracks and other macroscopic anomalies is found and prevented from entering the process machine in advance, the wafer can be effectively prevented from being further damaged to be cracked in the process machine, the loss of consumable materials of the corresponding machine of the wafer back process is reduced, the risk of abnormal maintenance of the process machine is reduced, and the productivity of the machine is improved while the process cost of the wafer back is reduced.

It should be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprise," "include," or any other variation thereof, are intended to cover a non-exclusive inclusion. In this specification, each embodiment is described in a related manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments.

The foregoing is merely a preferred embodiment of the present application and is not intended to limit the scope of the present application. It should be noted that, for a person skilled in the art, several improvements and modifications can be made without departing from the principle of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A wafer inspection apparatus, comprising:

a susceptor for placing a wafer;

the light source is arranged above the base and used for irradiating the surface of the wafer;

the photosensitive device is arranged above the base and is used for collecting reflected light information on the surface of the wafer; and the data processing unit is communicated with the photosensitive device and is used for acquiring and analyzing the reflected light information acquired by the photosensitive device so as to judge whether the wafer has a hidden injury with a fragmentation risk, wherein when the light intensity value in the reflected light information exceeds the light intensity standard threshold value set in the data processing unit, an alarm is triggered.

2. The wafer inspection apparatus of claim 1, wherein the data processing unit is further configured to: substituting the obtained reflected light information into a standard model of the reflected light of the surface of the normal wafer, which is obtained in advance, so as to lock the wafer defect.

3. The wafer inspection apparatus of claim 1 wherein the light source irradiates different portions of the wafer surface at the same angle.

4. The wafer inspection apparatus of claim 1 wherein the light source irradiates different portions of the wafer surface at different angles.

5. The wafer inspection apparatus of claim 1, wherein the light source is movable to illuminate the wafer surface at multiple angles.

6. The wafer inspection apparatus of claim 1, wherein the plurality of light sources illuminate the wafer surface simultaneously in multiple directions.

7. The apparatus of claim 1, wherein the plurality of photosensitive devices collect reflected light information from the surface of the wafer at a plurality of different angles.

8. The wafer inspection apparatus of claim 1, wherein the base is rotatable to rotate the wafer.

9. The wafer inspection apparatus of claim 1 wherein the light source is an infrared light source and the photosensitive device is an infrared camera.