CN117894706A

CN117894706A - Multi-mode wafer detection system and method

Info

Publication number: CN117894706A
Application number: CN202410298422.5A
Authority: CN
Inventors: 李宣令; 毕海; 李磊; 汪伟; 安宁
Original assignee: Individual
Current assignee: Individual
Priority date: 2024-03-15
Filing date: 2024-03-15
Publication date: 2024-04-16

Abstract

The invention discloses a multi-mode wafer detection system and method, and belongs to the technical field of wafer detection. The multi-mode wafer detection system of the invention comprises: the device comprises a detection module, a mechanical module and a control module; the mechanical module is used for placing a wafer sample to be detected; the detection module is used for carrying out multi-mode detection of appearance detection, color detection and electroluminescence detection on the wafer sample to be detected; the control module is used for controlling the mechanical module to move when different modes of detection are carried out on the wafer sample to be detected, so that the multi-mode detection of the wafer sample to be detected is completed, the wafer-level appearance detection, the photoluminescence detection and the electroluminescence detection are freely switched to detection means, the appearance and the color can be detected simultaneously, the overstock rate and the omission rate of the whole equipment are reduced, and the downstream manufacturing yield is improved.

Description

Multi-mode wafer detection system and method

Technical Field

The present invention relates to the field of wafer inspection technologies, and in particular, to a multi-mode wafer inspection system and method.

Background

And MicroLED, faults or non-uniformity are easy to generate in the manufacturing process of chips (micro light emitting diode displays), the coordinates of defective chips can be obtained before a chip transfer process by performing wafer-level detection, and the defective chips are repaired or discarded in subsequent manufacturing, so that the consistency of products is ensured, the yield of the products is improved, and the manufacturing cost is reduced. Currently, there are three main means for wafer level inspection at microLED on the market, AOI (Automated Optical Inspection, automated optical) appearance inspection, photoluminescence (PL) inspection, and Electroluminescence (EL) inspection.

However, the existing wafer detection mode can only perform single detection, has low detection universality, for example, AOI detection, and cannot detect other modes, so that the detection result is inaccurate.

Disclosure of Invention

The invention mainly aims to provide a multi-mode wafer detection system, which aims to solve the technical problems of low universality and low accuracy of wafer detection in the prior art.

To achieve the above object, the present invention provides a multi-mode wafer inspection system, including: the device comprises a detection module, a mechanical module and a control module;

The mechanical module is used for placing a wafer sample to be detected;

the detection module is used for carrying out multi-mode detection of appearance detection, color detection and electroluminescence detection on the wafer sample to be detected;

And the control module is used for controlling the mechanical module to move when detecting the wafer sample to be detected in different modes so as to finish the multi-mode detection of the wafer sample to be detected.

Optionally, the detection module includes: the device comprises a laser light emitting unit, an illumination unit, a vision acquisition unit and an automatic focusing unit;

The laser light-emitting unit is used for emitting light beams to form a laser light path;

The illumination unit is used for providing a light source to form an illumination light path;

The automatic focusing unit is used for focusing the wafer sample to be detected according to the laser light path and the illumination light path;

the vision acquisition unit is used for carrying out multi-mode detection on the wafer sample to be detected according to focusing of the automatic focusing unit.

Optionally, the laser light emitting unit includes: the full-return mirror, the homogenizer, the rectangular diaphragm, the first lens and the first beam splitter are sequentially arranged, the beam expander, the second beam splitter and the first laser are sequentially arranged above the full-return mirror, and the second laser is further arranged on the left side of the second beam splitter;

The first laser and the second laser simultaneously send out different light beams to enter the second beam splitter, and the light beams enter the beam expander after being combined by the second beam splitter;

The beam expander is used for expanding the combined light beam to obtain expanded light;

The full-return mirror is used for receiving the beam expansion light and reflecting the beam expansion light to the homogenizer;

The homogenizer is used for homogenizing the reflected beam expansion light to obtain homogenized light spots;

The rectangular diaphragm is used for adjusting the homogenized light spot to form a laser light path to the first lens;

The first lens and the first beam splitter are used for combining the laser light path and the illumination light path and sending the combined laser light path and the combined illumination light path into the vision acquisition unit to image on the surface of the wafer sample to be detected.

Optionally, the lighting unit comprises: the first light source, the condenser, the view field diaphragm and the reflector are sequentially arranged, and a second lens is arranged below the reflector;

the first light source is used for emitting a light source to the condenser lens, and collimated light is obtained through condensing by the condenser lens;

the view field diaphragm is used for receiving the collimated light, intercepting a platform area of the collimated light to form uniform light and transmitting the uniform light to the reflecting mirror;

The reflecting mirror is used for reflecting the uniform light to the second lens, forming an illumination light path through the cooperation of the second lens and the objective lens, and transmitting the illumination light path to the vision acquisition unit.

Optionally, the auto-focusing unit includes: the device comprises a third laser, a polaroid, a polarization beam splitter and a third lens which are sequentially arranged, wherein an infrared photoelectric detector is arranged below the polarization beam splitter, and the third laser is arranged deviating from an optical axis;

The third laser is used for emitting infrared laser to the polaroid and forming polarized laser through the polaroid;

the polarization beam splitter is used for receiving the polarized laser and transmitting the polarized laser to the third lens;

The third lens is used for irradiating the polarized laser to the surface of the wafer sample to be detected, receiving the reflected laser back to the polarized beam splitter, and reflecting the reflected laser to the infrared photoelectric detector through the polarized beam splitter;

and the infrared photoelectric detector is used for analyzing the reflected laser and carrying out focusing adjustment according to an analysis result.

Optionally, the vision acquisition unit includes: the device comprises an objective lens, a third beam splitter, a spectroscope, a three-filter switching group, a beam splitter prism, a first tube lens and an area array camera which are sequentially arranged from bottom to top, wherein the right side of the beam splitter prism is also provided with a second tube lens, a filter runner and an area array photoelectric detector which are sequentially arranged;

The third beam splitter is configured to receive the laser light path and the illumination light path, integrate the laser light path and the illumination light path into the objective lens, and receive visible light returned by the objective lens, where the visible light includes information of a wafer sample to be detected;

The third beam splitter is further configured to filter the visible light sequentially through the beam splitter and the three-filter switching group, and then transmit the filtered visible light to the beam splitter prism;

The beam splitting prism is used for splitting the filtered light into two beams to obtain a first beam and a second beam, wherein the first beam is imaged to the area array camera through the first tube mirror to perform appearance detection on the wafer sample to be detected, and the second beam is reflected to the second tube mirror and imaged to the area array photoelectric detector through the optical filter rotating wheel to perform color detection on the wafer sample to be detected.

Optionally, the mechanical module includes:

The objective turntable is used for installing objective lenses with different multiplying powers;

the wafer sample detection device comprises an electric turntable, wherein a sucker of a micro groove is fixed on the electric turntable, and a wafer sample to be detected is carried on the sucker;

The first vertical axis displacement table is used for bearing the electric turntable and matching with an automatic focusing unit in the detection module to finish automatic focusing in the process of scanning the wafer sample to be detected;

and the first transverse and longitudinal axis displacement platform is used for bearing the first vertical axis displacement platform and fixing the first vertical axis displacement platform.

Optionally, the detection module further comprises: a detection probe immobilized on the mechanical module;

And the control module is also used for controlling the mechanical module to move and controlling the detection probe to contact with the wafer sample to be detected when the wafer sample to be detected is subjected to electroluminescence detection.

Optionally, the mechanical module further comprises: the detection probe is fixed on the rotary sliding table, the rotary sliding table is connected with the second vertical axis displacement table, the second vertical axis displacement table is fixed on the second horizontal and vertical axis displacement table, and the second horizontal and vertical axis displacement table is positioned on two sides of the first horizontal and vertical axis displacement table;

And the control module is also used for controlling the rotary sliding table to move the detection probe to be in contact with the wafer sample to be detected when the wafer sample to be detected is subjected to electroluminescence detection.

In addition, in order to achieve the above object, the present invention further provides a multi-mode wafer inspection method, which is applied to the multi-mode wafer inspection system described above, the multi-mode wafer inspection system comprising: the method comprises the following steps of:

the mechanical module is used for placing a wafer sample to be detected;

The detection module performs appearance detection, color detection and electroluminescence detection on the wafer sample to be detected;

and when the control module detects the wafer sample to be detected in different modes, the mechanical module is controlled to move so as to complete the multi-mode detection of the wafer sample to be detected.

The multi-mode wafer detection system of the invention comprises: the device comprises a detection module, a mechanical module and a control module; the mechanical module is used for placing a wafer sample to be detected; the detection module is used for carrying out multi-mode detection of appearance detection, color detection and electroluminescence detection on the wafer sample to be detected; the control module is used for controlling the mechanical module to move when different modes of detection are carried out on the wafer sample to be detected, so that the multi-mode detection of the wafer sample to be detected is completed, the wafer-level appearance detection, the photoluminescence detection and the electroluminescence detection are freely switched to detection means, the appearance and the color can be detected simultaneously, the overstock rate and the omission rate of the whole equipment are reduced, and the downstream manufacturing yield is improved.

Drawings

FIG. 1 is a schematic diagram of a multi-mode wafer inspection system according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram of a multi-mode wafer inspection system according to a second embodiment of the present invention;

FIG. 3 is a schematic diagram of a laser light emitting unit in an embodiment of a multi-mode wafer inspection system according to the present invention;

FIG. 4 is a schematic diagram of an illumination unit in an embodiment of a multi-mode wafer inspection system according to the present invention;

FIG. 5 is a schematic diagram illustrating an auto-focus unit in an embodiment of a multi-mode wafer inspection system according to the present invention;

FIG. 6 is a schematic diagram of a vision acquisition unit in an embodiment of a multi-mode wafer inspection system according to the present invention;

FIG. 7 is a schematic diagram of a third embodiment of a multi-mode wafer inspection system according to the present invention;

FIG. 8 is a schematic diagram of images under different modes of inspection in an embodiment of a multi-mode wafer inspection system according to the present invention;

FIG. 9 is a schematic diagram of the overall structure of the multi-mode wafer inspection system of the present invention;

Fig. 10 is a flowchart of a multi-mode wafer inspection method according to a first embodiment of the present invention.

Reference numerals illustrate:

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a multi-mode wafer inspection system according to a first embodiment of the present invention.

In this embodiment, the multi-mode wafer inspection system includes: a detection module 1, a mechanical module 2 and a control module 3.

The AOI appearance detection collects the surface image of the LED wafer by using a machine vision technology, and automatically identifies and classifies defects by using an artificial intelligence algorithm. PL detection utilizes laser excitation microLED to self-emit light, and then the color of the excitation light is measured by a color measurement device, which is generally composed of a mobile platform, an integral colorimeter and an oblique irradiation laser. The EL detection uses the electrode or grid electrode to connect with the wafer electrode to observe whether the light emitting function is normal. AOI detection utilizes bright field illumination to detect the appearance of a wafer, and bad points with normal appearance and abnormal luminescence cannot be detected, so that missed detection is caused. The invention can select PL supplementary detection while AOI appearance detection, and make up for the deficiency of AOI detection.

Currently, main stream PL detection in the market is mostly based on a scheme of erecting a complete set of imaging colorimeter on a mobile platform and combining oblique illumination. Oblique illumination tends to cause uneven illumination. And the compatibility with AOI detection is poor, the detection is needed respectively, the time is consumed, and the bad point coordinates are needed to be additionally matched. The invention combines PL detection into AOI detection light path, and can detect the appearance and luminescence of the wafer at the same time. The coaxial excitation light path is introduced, so that the illumination uniformity is improved, the wavelength of the excitation light can be conveniently switched, and the multi-mode detection is completed.

EL detection is more accurate than AOI and PL detection, but the detection speed is slow. Large area gate electrodes and numerous non-contact EL detection are still under investigation and further practice is needed if they can be used in practical industrial manufacturing. Thus EL detection alone is far from meeting the needs of mass production. EL detection is required to be classified as spot check, and high-speed, high-efficiency and high-quality detection is realized by combining AOI and PL detection. In the embodiment, three detection modes are combined on one device, so that the wafer can be conveniently subjected to multi-mode detection.

In a specific implementation, the multi-mode wafer inspection system includes an inspection module 1, a mechanical module 2, and a control module 3.

In a specific implementation, the detection module 1 mainly completes functions of PL excitation, illumination, focusing, AOI detection, color measurement and the like, the mechanical module 2 is mainly used for performing functions of sample stage movement, probe movement during EL detection, optical filter switching and the like, and the control module 3 is responsible for coordinating the operation of the functions and completing wafer detection in cooperation.

In this embodiment, the mechanical module 2 is used for placing a wafer sample to be inspected.

It should be noted that, the wafer sample to be detected is microLED chips, and a sample stage is arranged in the mechanical module 2, so that the wafer sample to be detected is placed, and the mechanical module 2 is also used for moving the wafer sample to be detected, so as to meet the detection requirement.

In this embodiment, the detection module 1 is configured to perform multi-mode detection including appearance detection, color detection and electroluminescence detection on a wafer sample to be detected.

It should be noted that the detection module 1 has multiple modes of detection, such as appearance detection, color detection and electroluminescence detection, of the wafer sample to be detected, and each mode detection in the multiple modes can be performed simultaneously or sequentially.

In this embodiment, the control module 3 is configured to control the mechanical module 2 to move when detecting the wafer sample to be detected in different modes, so as to complete multi-mode detection of the wafer sample to be detected.

It should be noted that, when there is a detection requirement for the wafer sample to be detected, the control module 3 may control the movement of the mechanical module 2, so as to implement detection of different modes of the wafer sample to be detected.

The multi-mode wafer inspection system of the present embodiment includes: a detection module 1, a mechanical module 2 and a control module 3; the mechanical module 2 is used for placing a wafer sample to be detected; the detection module 1 is used for carrying out multi-mode detection of appearance detection, color detection and electroluminescence detection on a wafer sample to be detected; the control module 3 is configured to control the mechanical module 2 to move when detecting the wafer sample to be detected in different modes, so as to complete multi-mode detection of the wafer sample to be detected, freely switch detection means for wafer-level appearance detection, photoluminescence detection and electroluminescence detection, and enable appearance and color to be detected simultaneously, reduce over-detection rate and omission rate of the whole device, and improve downstream manufacturing yield.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a second embodiment of the multi-mode wafer inspection system according to the present invention.

In this embodiment, the detection module 1 includes: a laser light emitting unit 10, an illumination unit 11, a vision collecting unit 12, and an auto focusing unit 13.

The laser light emitting unit 10 is configured to emit a light beam to form a laser light path.

The laser light emitting unit 10 is configured to emit laser light of different colors, thereby forming a laser light path.

In this embodiment, the illumination unit 11 is configured to provide a light source to form an illumination light path.

It will be appreciated that the lighting unit 11 may provide additional light sources, such as LED light sources, whereby the emitted light sources form an illumination light path.

It should be noted that, the laser light path and the illumination pipeline can polish the wafer sample to be detected together, so that the wafer sample to be detected can be detected in different modes.

In this embodiment, the automatic focusing unit 13 is configured to focus the wafer sample to be detected according to the laser light path and the illumination light path; the vision collection unit 12 is configured to perform multi-mode detection on the wafer sample to be detected according to focusing of the auto-focusing unit 13.

It can be understood that the automatic focusing unit 13 can determine whether the wafer sample to be detected is out of focus according to the provided optical path, and automatically focus when the wafer sample is out of focus, so that the vision acquisition unit 12 shoots an image of the wafer sample to be detected according to the focused result, and multi-mode detection of the wafer sample to be detected is completed.

In the present embodiment, as shown in fig. 3, fig. 3 is a schematic structural view of the laser light emitting unit 10. The laser light emitting unit 10 includes: the full return mirror 101, the homogenizer 102, the rectangular diaphragm 103, the first lens 104 and the first beam splitter 105 are sequentially arranged, the beam expander 106, the second beam splitter 107 and the first laser 108 are sequentially arranged above the full return mirror 101, and the second laser 109 is further arranged on the left side of the second beam splitter 107.

It should be noted that, two lasers with different sizes are provided in the laser light emitting unit, the excitation effect of the 385nm laser on the blue light LED and the green light LED is obvious, and the excitation effect of the 532nm laser on the red light LED is obvious, so the first laser 108 is the 385nm laser, and the second laser 109 is the 532nm laser.

The first laser 108 and the second laser 109 simultaneously emit different light beams to enter the second beam splitter 107, and after being combined by the second beam splitter 107, the light beams enter the beam expander 106;

the beam expander 106 is configured to expand the combined beam to obtain expanded beam;

the total return mirror 101 is configured to receive the beam-expanded light and reflect the beam-expanded light to the homogenizer 102;

The homogenizer 102 is configured to homogenize the reflected beam-expanded light to obtain homogenized light spots;

The rectangular diaphragm 103 is configured to adjust the homogenized light spot, and form a laser path to the first lens 104;

The first lens 104 and the first beam splitter 105 are configured to combine the laser light path and the illumination light path and send the combined laser light path and the combined illumination light path to the vision acquisition unit 12, so as to image the surface of the wafer sample to be detected.

After different light beams are emitted by the first laser 108 and the second laser 109, the light beams propagate to the second beam splitter 107, the second beam splitter 107 is a short-wave-pass dichroic mirror, and the light beams emitted by the two lasers can be combined by the second beam splitter 107, so that the light beams enter the beam expander 106, are expanded by the beam expander 106, and then have a thicker diameter, so that the light beams strike the full-return mirror 101 to change the propagation direction, and are reflected to the homogenizer 102.

It will be appreciated that the total return mirror 101 is a reflecting mirror, and the purpose of adding the reflecting mirror is to change the spatial structure of the optical path so that the optical path is more compact, and the angle of the total return mirror 101 may be 30 degrees or 45 degrees inclined along the horizontal direction, which is not limited in this embodiment.

The homogenizer 102 is used to homogenize the reflected beam expander light, so as to convert the light beam into a uniform light spot, and obtain a homogenized light spot.

A rectangular diaphragm 103 with controllable patterns is placed in the working distance of the homogenizer 102, so that the light spot with the best homogenization quality is just presented at the diaphragm, and a final laser path is formed and transmitted to the first lens 104.

The vision acquisition unit 12 comprises an objective lens 121, the light beam passing through the rectangular diaphragm 103 forms a diaphragm, and the diaphragm images an image of the diaphragm on the surface of a wafer sample to be detected through a 4f system consisting of a follow-up first lens 104 and the objective lens 121, so that controllable laser excitation is provided for the wafer sample to be detected.

The first beam splitter 105 is a 50:50 beam splitter, and combines the laser light path with the illumination light path formed by the illumination unit 11 and sends the combined light path into the vision acquisition unit 12.

In this embodiment, as shown in fig. 4, fig. 4 is a schematic structural view of a lighting unit 11, and the lighting unit 11 includes: the first light source 111, the condenser 112, the field diaphragm 113 and the reflecting mirror 114 are sequentially arranged, and a second lens 115 is arranged below the reflecting mirror 114;

the first light source 111 is configured to emit a light source to the condenser 112, and collect the light through the condenser 112 to obtain collimated light;

the field stop 113 is configured to receive the collimated light, intercept a plateau region of the collimated light to form uniform light, and transmit the uniform light to the reflector 114;

The reflecting mirror 114 is configured to reflect the uniform light to the second lens 115, and form an illumination light path through cooperation of the second lens 115 and the objective lens 121, and transmit the illumination light path to the vision collecting unit 12.

It should be noted that, the first light source 111 may be an LED lamp, and emits an LED light source to the condenser 112. The condenser lens 112 condenses the LED light source into approximately collimated uniform light onto the field stop 113.

After receiving the uniform light, the field diaphragm 113 transmits the uniform light to the reflecting mirror 114, the reflecting mirror 114 is used for changing the space structure of the light path, the reflecting mirror 114 reflects the uniform light to the second lens 115 positioned below the reflecting mirror, so that an illumination light path is formed through the second lens 115, and the uniform light can be conjugate with the surface of the wafer sample to be detected through a 4f system consisting of the second lens 115 and the objective lens 121.

The illumination path may be combined with the laser path by a first beam splitter 105.

In this embodiment, as shown in fig. 5, fig. 5 is a schematic structural diagram of an autofocus unit 13, where the autofocus unit 13 includes: the third laser 131, the polaroid 132, the polarization beam splitter 133 and the third lens 134 are sequentially arranged, an infrared photoelectric detector 135 is further arranged below the polarization beam splitter 133, and the third laser 131 is arranged deviated from the optical axis;

the third laser 131 is configured to emit infrared laser light to the polarizer 132, and form polarized laser light through the polarizer 132;

The polarization beam splitter 133 is configured to receive the polarized laser light and transmit the polarized laser light to the third lens 134;

The third lens 134 is configured to irradiate the polarized laser beam onto the surface of the wafer sample to be detected, receive the reflected laser beam reflected back to the polarization beam splitter 133, and reflect the reflected laser beam to the infrared photoelectric detector 135 through the polarization beam splitter 133;

the infrared photoelectric detector 135 is configured to analyze the reflected laser beam, and perform focusing adjustment according to the analysis result.

It should be noted that, the third laser 131 is an infrared word line laser, and the third laser 131 is slightly disposed away from the optical axis, so that the incident laser has a slight angle with the optical axis, and the third laser 131 emits infrared laser to the polarizer 132.

The infrared laser light is changed into laser light having a horizontal or vertical polarization characteristic by the polarizer 132, and then is further transmitted to the third lens 134 by the polarization beam splitter 133. Since the third laser 131 is arranged in a deviating way, the center of a word line intersects with the center of the optical axis on the front focal plane of the third lens 134, the 4f system consisting of the third lens 134 and the objective lens 121 projects a word line image on the surface of the wafer sample to be detected, the infrared laser irradiated on the surface is reflected back to the infrared photoelectric detector 135 through the objective lens 121, the third lens 134 and the polarization beam splitter 133, as known by the principle of laser triangle, when the surface of the wafer sample to be detected is located on the focal plane, a bright spot in the middle of the field of view of the infrared photoelectric detector 135 can be clearly observed, and when the wafer sample to be detected is defocused upwards or downwards, the bright spot in the word line spreads towards different directions to become rectangular, and the farther the defocusing is, the wider the spread is. The defocusing condition can be judged according to the image analysis observed by the infrared photoelectric detector 135, real-time focusing can be achieved by matching with the Z-axis feedback of the mechanical module 2 objective table, and the wafer is always in a focal plane during scanning, so that the best imaging quality is achieved. Therefore, the infrared photodetector 135 can analyze the reflected laser light, so as to perform focus adjustment on the wafer sample to be inspected according to the analysis result.

In this embodiment, as shown in fig. 6, fig. 6 is a schematic structural diagram of the vision collecting unit 12, and the vision collecting unit 12 includes: the lens 121, the third beam splitter 122, the spectroscope 123, the three-filter switching group 124, the beam splitter prism 125, the first tube mirror 126 and the area array camera 127 are sequentially arranged from bottom to top, and a second tube mirror 128, a filter runner 129 and an area array photoelectric detector 130 are sequentially arranged on the right side of the beam splitter prism 125;

The third beam splitter 122 is configured to receive the laser light path and the illumination light path, integrate the laser light path and the illumination light path into the objective lens 121, and receive visible light returned by the objective lens 121, where the visible light includes information of a wafer sample to be detected;

The third beam splitter 122 is further configured to filter the visible light sequentially through the beam splitter 123 and the three-filter switching set 124, and then transmit the filtered visible light to the beam splitter prism 125;

The beam splitter prism 125 is configured to split the filtered light into two beams to obtain a first beam and a second beam, where the first beam is imaged by the first tube mirror 126 to the area array camera 127 to perform appearance detection of the wafer sample to be detected, and the second beam is reflected to the second tube mirror 128 and imaged by the filter wheel 129 to the area array photodetector 130 to perform color detection of the wafer sample to be detected.

It should be noted that, the objective lens 121 is disposed on the mechanical module 2, the objective lens 121 may be located directly under the third beam splitter 122 or inclined at a certain angle, and the number of objective lenses 121 may be plural, so that the wafer sample to be inspected is observed from multiple angles. The objective lens 121 is a microscope objective lens, and the magnification of the objective lens 121 is different, so that imaging with different magnifications can be performed.

The third beam splitter 122 is a short-wave-pass dichroic beam splitter, the third beam splitter 122 can reflect laser with infrared wavelength, the laser can transmit visible light and below, the third beam splitter 122 couples all light paths together and integrates the light into the objective lens 121, only visible light returned by the objective lens 121 can transmit the third beam splitter 122, the visible light comprises wafer sample information to be detected, the visible light passing through the third beam splitter 122 continues to pass through the spectroscope 123, and then the three-filter switching set 124 is provided.

The spectroscope 123 is R: t ratio is 30:70, and the three-filter switching set 124 includes two wave-limiting filters and a blank. The wave limiting filter corresponds to the photoluminescence excitation light wavelength 385nm and 532nm respectively, filters out the influence of corresponding laser, and the filtered light is transmitted into 50:50 beam splitting prism 125.

The light passing through the beam splitter prism 125 is split into two beams, and a first beam and a second beam are obtained, and the first beam is directly imaged to the area camera 127 through the first tube mirror 126.

The area camera 127 is a black-and-white area camera, and is used for performing AOI image appearance detection on the wafer sample to be detected.

The second light beam is reflected to the second tube mirror 128 and then imaged to the area array photoelectric detector 130 through the filter rotating wheel 129, and the filter rotating wheel 129 is provided with an XYZ three-color filter, so that color measurement can be performed by combining with the area array photoelectric detector 130.

It should be noted that, the XYZ filter wheel and the photodetector 130 for color collection may be replaced by a Bayer array type XYZ three-color filter coated color camera, so as to increase the detection speed.

The detection module 1 of this embodiment includes: a laser light emitting unit 10, an illumination unit 11, a vision collecting unit 12, and an auto focusing unit 13; the laser light emitting unit 10 is configured to emit a light beam to form a laser path; the illumination unit 11 is configured to provide a light source to form an illumination light path; the automatic focusing unit 13 is configured to focus the wafer sample to be detected according to the laser light path and the illumination light path; the vision acquisition unit 12 is configured to perform multi-mode detection on the wafer sample to be detected according to focusing of the automatic focusing unit 13, so as to meet different detection requirements, and the appearance and self-luminous characteristics can be obtained only by scanning once without separating appearance detection and color detection, thereby saving detection time and improving detection rate.

Referring to fig. 7, fig. 7 is a schematic structural diagram of a third embodiment of a multi-mode wafer inspection system according to the present invention.

In this embodiment, the mechanical module 2 includes:

an objective lens turntable 20 for mounting objective lenses 121 of different magnifications;

An electric turntable 21, wherein a sucker of a micro groove is fixed on the electric turntable 21, and a wafer sample to be detected is carried on the sucker;

a first vertical axis displacement table 22 for carrying the electric turntable 21 and matching with the automatic focusing unit 13 in the detection module 1 to complete automatic focusing in the process of scanning the wafer sample to be detected;

the first horizontal/vertical axis displacement stage 23 carries the first vertical axis displacement stage 22, and fixes the first vertical axis displacement stage 22.

The mechanical module 2 includes an objective turret 20, the objective turret 20 is an electric objective turret 20, and the objective lenses 121 with different magnifications are mounted on the electric objective turret 20.

The electric turntable 21 is fixedly provided with the sucking disc with the micro groove, and the wafer sample to be detected is placed on the sucking disc with the micro groove, so that different angle adjustment can be performed, and the angle of the wafer sample to be detected placed on the sucking disc can be conveniently adjusted.

It should be noted that, the electric turntable 21 is mounted on a first vertical axis displacement table 22, the first vertical axis displacement table 22 is a Z axis displacement table, and the first vertical axis displacement table 22 cooperates with the auto-focusing unit 13 in the detection module 1 to complete auto-focusing in the process of scanning the wafer sample to be detected.

It will be appreciated that the first vertical axis displacement stage 22 is integrally mounted on the first horizontal axis displacement stage 23, thereby forming an integral sample stage. The integral sample stage has xyz and an adjustable angle is four-degree-of-freedom manipulation capability.

The first transverse-longitudinal axis displacement stage 23 is an XY biaxial displacement stage. The first horizontal-vertical axis displacement stage 23 may fix the first vertical axis displacement stage 22.

In this embodiment, the detection module 1 further includes: a detection probe 14, said detection probe 14 being fixed on said mechanical module 2; the control module 3 is further configured to control the mechanical module 2 to move and control the detection probe 14 to contact with the wafer sample to be detected when the wafer sample to be detected is subjected to electroluminescence detection.

It should be noted that, the detection module 1 is further provided with a detection probe 14, and the detection probe 14 can move during EL measurement, so that the detection probe 14 contacts with the wafer sample to be detected, thereby realizing electroluminescent detection of the wafer sample to be detected.

In this embodiment, the mechanical module 2 further includes: a rotary sliding table 24, a second vertical axis displacement table 25 and a second horizontal and vertical axis displacement table 26, wherein the detection probe 14 is fixed on the rotary sliding table 24, the rotary sliding table 24 is connected to the second vertical axis displacement table 25, the second vertical axis displacement table 25 is fixed on the second horizontal and vertical axis displacement table 26, and the second horizontal and vertical axis displacement tables 26 are positioned on two sides of the first horizontal and vertical axis displacement table 23;

the control module 3 is further configured to control the rotating sliding table 24 to move the detection probe 14 into contact with the wafer sample to be detected when the wafer sample to be detected is subjected to electroluminescence detection.

It will be appreciated that the two sides of the first transverse-longitudinal axis displacement table 23 are provided with mechanical arms for fixing the detection probe 14, and specifically include a rotary sliding table 24, a second vertical axis displacement table 25 and a second transverse-longitudinal axis displacement table 26.

The detection probe 14 is fixed on the rotary sliding table 24, the rear end connecting line passes through the rotary sliding table 24, the rotary sliding table 24 is connected to a second vertical axis displacement table 25, the second vertical axis displacement table 25 is a Z-axis displacement table, and the second vertical axis displacement table 25 is fixed on a second transverse-longitudinal axis displacement table 26, so that the detection probe 14 also has four degrees of freedom of XYZ and adjustable angles, the contact between the detection probe 14 and a wafer sample to be detected is controlled by the control module 3, and when electroluminescent detection is required, the detection probe 14 is controlled to move in a visual field.

The PL detection laser of the invention projects uniform illumination at the adjustable mechanical diaphragm to the surface of the wafer for excitation in a projection mode, so that the shape can be changed, and only microLED with a specific rectangle size is excited in a view field. As shown in fig. 8, fig. 8 is a schematic image diagram under different mode detection, where the left side is LED illumination, the right side is laser illumination, and in the process of moving scanning, the area just subjected to AOI detection is moved to the right half a transverse field of view, and then is in a laser irradiation state, and PL detection is performed by laser excitation. In the figure, the black square example appearance inspection qualified chip finds abnormal light emitting color under PL inspection.

As shown in fig. 9, fig. 9 is a schematic diagram of the overall structure of the multi-mode wafer inspection system according to the present embodiment, the laser light emitting unit 10 and the illumination unit 11 in the inspection module respectively form a laser light path and an illumination light path, so as to be combined and sent to the vision acquisition unit 12, the automatic focusing unit 13 performs focusing, the vision acquisition unit 12 performs AOI inspection and color measurement, the machine module 2 places a wafer sample to be inspected, and the control module (not shown in the drawing) controls the machine module 2 to move during the measurement, so as to perform the measurement of different modes.

An embodiment of the present invention provides a multi-mode wafer inspection method, and referring to fig. 10, fig. 10 is a flowchart of a first embodiment of the multi-mode wafer inspection method of the present invention.

In this embodiment, the multi-mode wafer inspection method is applied to the multi-mode wafer inspection system described above, and the multi-mode wafer inspection system includes: the device comprises a detection module, a mechanical module and a control module.

The method comprises the following steps:

step S10: the mechanical module is used for placing a wafer sample to be detected.

The mechanical module is mainly used for performing functions such as sample stage movement, probe movement during EL detection, and filter switching.

The wafer sample to be detected is microLED chips, and a sample table is arranged in the mechanical module, so that the wafer sample to be detected is placed, and the mechanical module is also used for moving the wafer sample to be detected, so that the detection requirement is met.

Step S20: the detection module performs appearance detection, color detection and electroluminescence detection on the wafer sample to be detected.

It should be noted that the detection module is simultaneously provided with detection of multiple modes of the wafer sample to be detected, such as appearance detection, color detection and electroluminescence detection, and detection of each mode of the multiple modes can be simultaneously performed or sequentially switched.

Step S30: and when the control module detects the wafer sample to be detected in different modes, the mechanical module is controlled to move so as to complete the multi-mode detection of the wafer sample to be detected.

It should be noted that, when there is a detection requirement for the wafer sample to be detected, the mechanical module can be controlled to move by the control module, so as to realize detection of different modes of the wafer sample to be detected.

In the embodiment, a wafer sample to be detected is placed through a mechanical module; the detection module performs appearance detection, color detection and electroluminescence detection on the wafer sample to be detected; when the wafer sample to be detected is detected in different modes, the control module controls the mechanical module to move so as to finish multi-mode detection of the wafer sample to be detected, freely switches detection means for wafer-level appearance detection, photoluminescence detection and electroluminescence detection, can realize appearance and color simultaneous detection, reduces the overstock rate and the omission rate of the whole equipment, and improves the downstream manufacturing yield.

It should be understood that the foregoing is illustrative only and is not limiting, and that in specific applications, those skilled in the art may set the invention as desired, and the invention is not limited thereto.

It should be noted that the above-described working procedure is merely illustrative, and does not limit the scope of the present invention, and in practical application, a person skilled in the art may select part or all of them according to actual needs to achieve the purpose of the embodiment, which is not limited herein.

In addition, technical details not described in detail in the present embodiment may refer to the multi-mode wafer detection method provided in any embodiment of the present invention, which is not described herein.

Furthermore, it should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.

The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. Read Only Memory)/RAM, magnetic disk, optical disk) and including several instructions for causing a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) to perform the method according to the embodiments of the present invention.

The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the invention, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.

Claims

1. A multi-modal wafer inspection system, the multi-modal wafer inspection system comprising: the device comprises a detection module, a mechanical module and a control module;

The mechanical module is used for placing a wafer sample to be detected;

2. The multi-mode wafer inspection system of claim 1, wherein the inspection module comprises: the device comprises a laser light emitting unit, an illumination unit, a vision acquisition unit and an automatic focusing unit;

3. The multi-mode wafer inspection system of claim 2, wherein the laser light emitting unit comprises: the full-return mirror, the homogenizer, the rectangular diaphragm, the first lens and the first beam splitter are sequentially arranged, the beam expander, the second beam splitter and the first laser are sequentially arranged above the full-return mirror, and the second laser is further arranged on the left side of the second beam splitter;

4. The multi-modality wafer inspection system of claim 2, wherein the illumination unit comprises: the first light source, the condenser, the view field diaphragm and the reflector are sequentially arranged, and a second lens is arranged below the reflector;

5. The multi-modality wafer inspection system of claim 2, wherein the auto-focus unit comprises: the device comprises a third laser, a polaroid, a polarization beam splitter and a third lens which are sequentially arranged, wherein an infrared photoelectric detector is arranged below the polarization beam splitter, and the third laser is arranged deviating from an optical axis;

6. The multi-modality wafer inspection system of claim 2, wherein the vision acquisition unit comprises: the device comprises an objective lens, a third beam splitter, a spectroscope, a three-filter switching group, a beam splitter prism, a first tube lens and an area array camera which are sequentially arranged from bottom to top, wherein the right side of the beam splitter prism is also provided with a second tube lens, a filter runner and an area array photoelectric detector which are sequentially arranged;

7. The multi-mode wafer inspection system of claim 1, wherein the mechanical module comprises:

8. The multi-modal wafer inspection system as set forth in claim 7 wherein the inspection module further comprises: a detection probe immobilized on the mechanical module;

9. The multi-mode wafer inspection system of claim 8, wherein the mechanical module further comprises: the detection probe is fixed on the rotary sliding table, the rotary sliding table is connected with the second vertical axis displacement table, the second vertical axis displacement table is fixed on the second horizontal and vertical axis displacement table, and the second horizontal and vertical axis displacement table is positioned on two sides of the first horizontal and vertical axis displacement table;

10. A multi-mode wafer inspection method, wherein the multi-mode wafer inspection method is applied to the multi-mode wafer inspection system according to any one of claims 1 to 9, and the multi-mode wafer inspection system comprises: the system comprises a detection module, a mechanical module and a control module, wherein the method comprises the following steps:

the mechanical module is used for placing a wafer sample to be detected;