WO2022042344A1

WO2022042344A1 - Test chip and test system

Info

Publication number: WO2022042344A1
Application number: PCT/CN2021/112615
Authority: WO
Inventors: 郑兆祯; 丁新琪; 廖桂波; 吴阳烽; 焦旺; 王菊; 涂庆明
Original assignee: 深圳市中光工业技术研究院
Priority date: 2020-08-31
Filing date: 2021-08-13
Publication date: 2022-03-03
Also published as: CN114121698A

Abstract

A test chip. The test chip (12) is embedded into a semiconductor wafer (11) body and is used for performing a photoluminescence test. The test chip (12) comprises a plurality of quantum well intermixing areas (122) and non-quantum well intermixing areas (121) which are periodically arranged or randomly arranged, wherein the particle doping of the quantum well intermixing areas (122) is the same as that of a quantum well doping layer included in the semiconductor wafer (11) body. Laser beams are received by means of a plurality of quantum well intermixing areas (122), so as to generate a photoluminescence reaction, and interference occurs between light emitted by means of the photoluminescence of the plurality of quantum well intermixing areas (122), such that the intensity of a wavelength spectrum line signal emitted by the test chip (12) is enhanced, and the wavelength blue-shift situation of the test chip (12) can be measured by using a conventional spectrometer (40), thereby rapidly determining an anti-COD characteristic of a semiconductor wafer (11).

Description

A detection chip and detection system

technical field

The present application relates to the field of lasers, and in particular, to a detection chip and a detection system.

Background technique

Due to the advantages of small size, high efficiency, long life, and wide coverage of wavelengths, semiconductor lasers have been widely used in industry, medical care, beauty and other fields in recent years. In the prior art, semiconductor lasers are prone to COMD (Catastrophic Optical Mirror Damage) on the light-emitting surface. COMD is one of the important reasons for restricting the high-power light output and reliability of semiconductor lasers; reducing or eliminating light absorption on the light-emitting surface. , which can effectively increase the threshold power for the occurrence of COMD.

To reduce the light absorption of the light-emitting surface of the semiconductor laser, the general practice is to increase the forbidden band width of the semiconductor material at the light-emitting surface. The band gap of the quantum well material remains unchanged in other regions, especially the quantum well material under the current injection region, so that the photoluminescence (PL) of the quantum well material at the light-emitting surface of the semiconductor laser is relative to the laser wavelength of the laser. The occurrence of blue shift, or in other words, the wavelength blue shift of photoluminescence is an important basis for judging the mixing of quantum wells in semiconductor lasers.

The photoluminescence intensity of conventional semiconductor laser quantum wells is relatively weak, and a large irradiation area or high-power laser irradiation is required to generate a spectral test signal with sufficient intensity, resulting in the production of semiconductor lasers that need to sacrifice a larger test area. At the same time the test area cannot be used for the final product. Therefore, at present, semiconductor laser photoluminescence is only used for epitaxial wafer monitoring. In chip technology, blank wafers are often used for measurement after coating and heat treatment, and are not used in real production semiconductor wafers.

SUMMARY OF THE INVENTION

The present application provides a detection chip and a detection system to solve the technical problems in the prior art.

In order to solve the above technical problems, the present application provides a detection chip, which is embedded in a semiconductor wafer body and used for photoluminescence testing, and the detection chip includes:

A plurality of periodically arranged or randomly arranged quantum well intermixed regions and non-quantum well intermixed regions, wherein the particle doping of the quantum well intermingled regions is the same as the particle doping of the quantum well doping layer contained in the semiconductor wafer body Miscellaneous the same.

In one embodiment, the quantum well mixed region is a test line, and the test line and the non-quantum well mixed region are arranged alternately.

In one embodiment, the quantum well mixed regions are linearly arranged, and the distances between any adjacent quantum well mixed regions are equal or unequal.

In one embodiment, the quantum well mixed region is a test pattern, the non-quantum well mixed region is disposed around the test pattern, and a plurality of the test patterns are arranged in a matrix.

In one embodiment, the test pattern includes at least one of a square, a circle, a triangle or a polygon.

In one embodiment, the total area of the plurality of quantum well mixed regions is 0.5mm ² -1.5mm ² .

In one embodiment, the ratio of the total area of the plurality of quantum well mixed regions to the total area of the plurality of non-quantum well mixed regions ranges from 5 to 10.

In one embodiment, the distance between the surface of the quantum well hybrid region and the surface of the non-quantum well hybrid region is less than 2 μm.

In one embodiment, the detection chip further includes at least one alignment mark for alignment.

In order to solve the above-mentioned technical problems, the present application also provides a detection system for testing the above-mentioned detection chip, including:

semiconductor workbench;

a laser light source, used to generate a laser beam, the laser beam is irradiated to the detection chip carried on the semiconductor table, so that the detection chip has a photoluminescence reaction and emits light;

a spectrometer, receiving the light through a light processing system, detecting the light, and measuring the wavelength spectrum of the detection chip;

The imaging system is connected to the spectrometer through a USB data line, images the wavelength spectrum line, and displays the blue shift of the wavelength spectrum line, so as to judge the anti-COD characteristic of the semiconductor wafer.

The beneficial effects of the present application are: different from the prior art, the detection chip of the present application includes quantum well hybrid regions and non-quantum well hybrid regions arranged periodically or randomly, and receives laser beams through a plurality of quantum well hybrid regions to generate In the photoluminescence reaction, interference occurs between the light emitted by the photoluminescence in the mixed regions of the quantum wells, so that the signal intensity of the wavelength spectrum line emitted by the detection chip is enhanced, and the wavelength of the detection chip can be measured by a conventional spectrometer. In the case of blue shift, it can quickly realize the judgment of the anti-COD characteristics of semiconductor wafers. It is easy to operate and does not need to use other expensive equipment for detection, which can improve the detection efficiency and increase the production capacity.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic plan view of an embodiment of a semiconductor wafer of the present application;

2 is a schematic plan view of an embodiment of a detection chip of the present application;

3 is a schematic plan view of another embodiment of the detection chip of the present application;

4 is a schematic plan view of another embodiment of the detection chip of the present application;

5 is a schematic plan view of another embodiment of the detection chip of the present application;

6 is a schematic cross-sectional view of an embodiment of a detection chip of the present application;

7 is a schematic cross-sectional view of another embodiment of the detection chip of the present application;

8 is a schematic cross-sectional view of another embodiment of the detection chip of the present application;

FIG. 9 is a schematic structural diagram of an embodiment of the detection system of the present application.

detailed description

In order to enable those skilled in the art to better understand the technical solutions of the present application, the detection system and the detection chip provided by the present application are described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally also includes For other steps or units inherent to these processes, methods, products or devices.

Please refer to FIG. 1 . FIG. 1 is a schematic plan view of a semiconductor wafer according to an embodiment of the present application. The semiconductor wafer 11 is embedded with a detection chip 12, and a plurality of laser resonators and cutting lines are formed on the semiconductor wafer 11, and N laser chips 13 of the same or different sizes can be formed by cutting or splitting, wherein the detection chip 12 also includes At least one alignment mark 14 for alignment, further, the alignment mark 14 can be aligned with the alignment mark of the semiconductor wafer 11 when the detection chip 12 is embedded in the semiconductor wafer 11, so that the detection chip 12 can be quickly embedded At the correct position of the semiconductor wafer 11, the alignment mark 14 can also be detected by the detection device, and the alignment mark can be quickly positioned to the area of the detection chip 12 for detection, thereby improving detection efficiency and detection accuracy.

In the prior art, it is necessary to further perform a photoluminescence PL test on the laser chip 13 that has been cut to measure the wavelength blue shift of the QWI processed by thermal diffusion, ion implantation or strained layer, so as to further judge the anti-COD characteristics of the laser chip 13 . In this embodiment, by directly performing the photoluminescence test on the detection chip 12 of the semiconductor wafer 11, the detection result of the anti-COD characteristic of the laser chip 13 related to the semiconductor wafer 11 can be obtained, that is to say, only one inspection is required. , the average anti-COD characteristics of the N laser chips 13 on the semiconductor wafer 11 can be obtained, and there is no need to detect each laser chip 13 individually, which can effectively improve the detection efficiency, simplify the preparation process of the laser chips 13 and improve the productivity.

Referring further to FIG. 2, FIG. 2 is a first schematic plan view of an embodiment of the detection chip of the present application. The detection chip 12 includes a quantum well mixed region 122 and a non-quantum well mixed region 121 . Wherein, the quantum well mixed region 122 is the same as the QWI obtained by thermal diffusion, ion implantation or strain layer processing of the entire semiconductor wafer 11, that is, the detection chip 12 is obtained by subjecting the semiconductor wafer 11 to thermal diffusion, ion implantation or strain layer processing. The obtained QWIs are spliced together, and the epitaxial structure of each quantum well hybrid region 122 of the detection chip 12 is the same as the QWI of the semiconductor wafer 11. By measuring the photoluminescence of the quantum well hybrid region 122 of the detection chip 12, the wavelength The anti-COD capability of the laser chip 13 included in the entire semiconductor wafer 11 can be judged by the blue shift of the entire semiconductor wafer 11 .

Optionally, the quantum well intermixed regions 122 of the detection chip 12 may be periodically arranged test lines or test patterns, or the quantum well intermixed regions 122 of the detection chip 12 may be aperiodically arranged test lines and test patterns. In the present application, the total area of the detection area is increased by arranging the quantum well hybrid regions 122 periodically or non-periodically, and at the same time, the light emitted from the multiple quantum well hybrid regions 122 is used to interfere with each other, so as to enhance the photoluminescence wavelength spectrum of the detection chip 12. The signal strength is used to quickly detect the wavelength blue shift of the QWI of the semiconductor wafer 11 , and then be used to judge the anti-COD capability of the laser chip 13 included in the semiconductor wafer 11 .

The detection chip 12 will be described below with reference to specific embodiments.

As shown in FIG. 2 , the quantum well mixed region 122 is a test line, the quantum well mixed region 122 and the non-quantum well mixed region 121 are alternately arranged periodically, and the quantum well mixed region 122 is linearly arranged, and any adjacent linearly arranged The distances between the quantum well mixed regions 122 are equal, that is, the widths of all non-quantum well mixed regions 121 are equal. The width d1 of the quantum well mixed region 122 is much smaller than the width d2 of the non-quantum well mixed region 121 , so that the area of the quantum well mixed region 122 is much smaller than that of the non-quantum well mixed region 121 . The width d1 of the quantum well mixed region 122 is 10 μm, and the width d2 of the non-quantum well mixed region 121 is 90 μm. In the present application, the total area of the detection area is increased by arranging the quantum well hybrid regions 122 periodically or non-periodically, and at the same time, the light emitted from the multiple quantum well hybrid regions 122 is used to interfere with each other, so as to enhance the photoluminescence wavelength spectrum of the detection chip 12. The signal strength is used to quickly detect the wavelength blue shift of the QWI of the semiconductor wafer 11 , and then be used to judge the anti-COD capability of the laser chip 13 included in the semiconductor wafer 11 .

Referring further to FIG. 3 , FIG. 3 is a schematic plan view of another embodiment of the detection chip of the present application. Different from the above embodiments, the distances between any adjacent quantum well mixed regions 122 in this embodiment are unequal, and a plurality of quantum well mixed regions 122 are regularly distributed. As shown in FIG. 3, the distance between the nth quantum well mixed region 122 and the n+1th quantum well mixed region 122 is d3, and the n+1st quantum well mixed region 122 and the n+2th quantum well The distance between the mixed regions 122 is d4, and d3 is greater than d4, where n is 1, 3, and 5. Optionally, in other embodiments, the number of quantum well mixed regions 122 may be 8, 10, or 12, or the like. In the present application, the total area of the detection area is increased by arranging the quantum well hybrid regions 122 periodically or non-periodically, and at the same time, the light emitted from the multiple quantum well hybrid regions 122 is used to interfere with each other, so as to enhance the photoluminescence wavelength spectrum of the detection chip 12. The signal strength is used to quickly detect the wavelength blue shift of the QWI of the semiconductor wafer 11 , and then be used to judge the anti-COD capability of the laser chip 13 included in the semiconductor wafer 11 .

Referring further to FIG. 4 , FIG. 4 is a schematic plan view of yet another embodiment of the detection chip of the present application. As shown in FIG. 4 , the quantum well mixed region 122 is a test pattern, the non-quantum well mixed region 121 is arranged around the quantum well mixed region 122 , and a plurality of quantum well mixed regions 122 are arranged in a matrix. The quantum well mixed region 122 is square. Optionally, in other embodiments, the quantum well mixed region 122 may be a circle, a triangle, a polygon, or the like. The total area of the plurality of quantum well mixed regions 122 is S1, and the range of S1 is 0.5 mm ² -1.5 mm ² . Alternatively, S1 may be 1 mm ² . The total area of the non-detection area 121 is S2, and the ratio of S1 to S2 ranges from 5 to 10. In the present application, the total area of the detection region is increased by arranging the quantum well hybrid regions 122 periodically or aperiodically, and at the same time, the light emitted from the multiple quantum well hybrid regions 122 is used to interfere with each other to enhance the detection chip 12. The photoluminescence wavelength spectrum The signal intensity is used to quickly detect the wavelength blue shift of the QWI of the semiconductor wafer 11 , and then be used to judge the anti-COD capability of the laser chip 13 included in the semiconductor wafer 11 .

Referring further to FIG. 5 , FIG. 5 is a schematic plan view of another embodiment of the detection chip of the present application. Different from the above embodiments, the quantum well mixed region 122 in this embodiment includes a triangular quantum well mixed region 122 and a circular quantum well mixed region 122 . As shown in FIG. 5 , the triangular quantum well mixed regions 122 and the circular quantum well mixed regions 122 are alternately arranged, so that the quantum well mixed regions 122 are regularly arranged periodically. Optionally, in other embodiments, the quantum well intermixed region 122 may be formed by a combination of any two shapes of a circle, a triangle or a polygon, such as a circle and a rectangle, a triangle and a rectangle, and the like.

In the prior art, the area of the QWI area on the laser chip is small, usually 10 μm ² , and a microPL instrument needs to be used to detect the small area. The microPL instrument is relatively expensive, and the operation is complicated, which is not conducive to the needs of actual production; on the other hand , the photoluminescence intensity of QWI is weak, and a larger irradiation area or laser power needs to be used, resulting in damage to the semiconductor wafer 11 located in the detection area, reducing the output and increasing the production cost. In the present application, the total area of the detection region is increased by arranging the quantum well hybrid regions 122 periodically or aperiodically, and at the same time, the light emitted from the multiple quantum well hybrid regions 122 is used to interfere with each other to enhance the detection chip 12. The photoluminescence wavelength spectrum The signal intensity is used to quickly detect the wavelength blue shift of the QWI of the semiconductor wafer 11 , and then be used to judge the anti-COD capability of the laser chip 13 included in the semiconductor wafer 11 .

Further referring to FIGS. 6-8 , FIG. 6 is a schematic cross-sectional view of an embodiment of the detection chip of the present application, FIG. 7 is a schematic cross-sectional plan view of another embodiment of the detection chip of the present application, and FIG. 8 is a schematic view of another embodiment of the detection chip of the present application. Schematic cross section.

The distance between the surface of the quantum well mixed region 122 and the surface of the non-detection region 121 is less than 2 μm, taking the linear quantum well mixed region 122 of FIG. 2 as an example. In other embodiments, the distance between the surface of the quantum well mixed region 122 and the surface of the non-quantum well mixed region 121 is less than 2 μm.

As shown in FIG. 6 , the distance between the surface of the linear quantum well mixed region 122 and the surface of the non-quantum well mixed region 121 is h1 , and h1 is less than 2 μm, that is, the range of h1 is 0 μm-2 μm. As shown in FIG. 7 , the distance between the surface of the linear quantum well mixed region 122 and the surface of the non-quantum well mixed region 121 is h2, and h2 is less than 2 μm, that is, the range of h2 is 0 μm-2 μm.

Optionally, when h1 or h2 is 0 μm, as shown in FIG. 8 , the distance between the surface of the linear quantum well mixed region 122 and the surface of the non-quantum well mixed region 121 is 0 μm, that is, the distance of the linear quantum well mixed region 122 is 0 μm. The surface is just flush with the surface of the non-quantum well impurity region 121 .

In actual production, due to operation errors or equipment errors, the surface splicing of the quantum well hybrid region 122 and the non-quantum well hybrid region 121 is deviated. The error value of the distance between them is 2 μm, which only needs to satisfy this condition, which is convenient for screening the detection chips 12 .

Please refer to FIG. 9 , which is a schematic structural diagram of an embodiment of the detection system of the present application. As shown in FIG. 9 , the detection system 1 includes a laser light source 20 , a light processing system 30 , a spectrometer 40 , an imaging system 50 , a USB data line 60 and a semiconductor stage 70 . The light processing system 30 includes a light collector 31 and a light conductor 32 . The imaging system 50 is a computer with data processing software.

The semiconductor wafer 11 is carried on the semiconductor table 70 , and the laser light source 20 generates a laser beam and irradiates the detection chip 12 on the semiconductor wafer 11 ; the detection chip 12 in the semiconductor wafer 11 receives the laser beam to generate photoluminescence The light collector 31 collects the light emitted by the detection chip 12, the light transmission member 32 transmits the light to the spectrometer 40, and the spectrometer 40 detects the collected light, and the wavelength spectrum of the detection chip 12 is obtained by measurement. The imaging system 50 is connected with the spectrometer 40 through the USB data line 60, and the wavelength spectral line data obtained from the spectrometer 40 is imaged, and the blue shift of the wavelength spectral line is displayed through the display screen to judge the anti-COD of the semiconductor wafer 11. characteristic.

Optionally, in other embodiments, other connecting lines with data transmission function can be used to connect the imaging system 50 and the spectrometer 40 .

Among them, COD (catastrophic optical damage) or COBD (catastrophic optical body damage) or COMD (catastrophic optical mirror damage), COBD is mainly due to semiconductor wafers11 It is caused by damage to the internal structure, while COMD is mainly caused by the damage of the mirror surface of the optical resonant cavity of the semiconductor component.

Different from the practice of using an empty wafer in the prior art and performing measurement after coating and heat treatment, in this embodiment, the detection chip 12 is embedded in the semiconductor wafer 11, and the detection chip 12 is used to receive a laser beam to generate a photoluminescence reaction. The detection of the anti-COD characteristic of the semiconductor wafer 11 does not need to use other detection equipment to detect whether there is a COMD, which effectively improves the detection efficiency and reduces the detection cost. Before the semiconductor wafer 11 is cut to form the laser chip 13, in this embodiment, the anti-COD characteristic of the semiconductor wafer 11 is detected, so that problems can be found in time, the process of the semiconductor wafer 11 can be adjusted, and the quality of the semiconductor wafer 11 can be improved. Reduce scrap rate and lower production costs.

The above are only the embodiments of the present application, and are not intended to limit the scope of the patent of the present application. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present application, or directly or indirectly applied in other related technical fields, All the same are included in the scope of patent protection of the present application.

Claims

A detection chip, characterized in that the detection chip is embedded in a semiconductor wafer body for performing photoluminescence testing, and the detection chip comprises:

A plurality of periodically arranged or randomly arranged quantum well intermixed regions and non-quantum well intermixed regions, wherein the particle doping of the quantum well intermingled regions is the same as the particle doping of the quantum well doping layer contained in the semiconductor wafer body Miscellaneous the same.
The detection chip according to claim 1, wherein the quantum well mixed region is a test line, and the test line and the non-quantum well mixed region are alternately arranged.
The detection chip according to claim 2, wherein the quantum well mixed regions are linearly arranged, and the distances between any adjacent quantum well mixed regions are equal or unequal.
The detection chip according to claim 1, wherein the quantum well mixed region is a test pattern, the non-quantum well mixed region is arranged around the test pattern, and a plurality of the test patterns are arranged in a matrix.
The detection chip according to claim 4, wherein the test pattern comprises at least one of a square, a circle, a triangle or a polygon.
The detection chip according to claim 1, wherein the total area of the plurality of quantum well mixed regions is 0.5 mm 2 -1.5 mm 2 .
The detection chip according to claim 6, wherein the ratio of the total area of the plurality of quantum well mixed regions to the total area of the plurality of non-quantum well mixed regions ranges from 5 to 10.
The detection chip according to claim 1, wherein the distance between the surface of the quantum well mixed region and the surface of the non-quantum well mixed region is less than 2 μm.
The detection chip according to claim 1, wherein the detection chip further comprises at least one alignment mark used for alignment.
A detection system for testing the detection chip according to any one of claims 1-9, characterized in that, comprising:

semiconductor workbench;

a laser light source, used to generate a laser beam, the laser beam is irradiated to the detection chip carried on the semiconductor table, so that the detection chip has a photoluminescence reaction and emits light;

a spectrometer, receiving the light through a light processing system, detecting the light, and measuring the wavelength spectrum of the detection chip;

The imaging system is connected to the spectrometer through a USB data line, images the wavelength spectrum line, and displays the blue shift of the wavelength spectrum line, so as to judge the anti-COD characteristic of the semiconductor wafer.