Method for monitoring tellurium-cadmium-mercury infrared detector chip

Abstract

The invention discloses a monitoring method of a mercury-cadmium-telluride infrared detector chip, and belongs to the technical field of infrared detectors, the monitoring method of the mercury-cadmium-telluride infrared detector chip comprises the following steps: providing a chip to be detected; corroding the to-be-detected chip in an HCl solution to remove a covering layer on the to-be-detected chip; hydrobromic acid and bromine are used for preparing a solution according to a certain proportion, the chip to be detected is soaked so as to remove the tellurium-cadmium-mercury material layer, and the covering layer is made of zinc sulfide. The covering layer on the surface of the to-be-tested chip is removed through HCl solution corrosion, then the tellurium-cadmium-mercury material layer in the to-be-tested chip is removed, the phenomenon that the to-be-tested chip is cracked due to bubbles of the bottom filling glue layer due to strong impact is avoided, the bottom filling glue layer is not damaged when all the material layers are removed through soaking, and the natural condition of the bubbles of the bottom filling glue can be directly observed.

Description

Technical Field

[0001] The invention relates to the technical field of infrared detectors, and in particular to a monitoring method for a mercury cadmium telluride infrared detector chip. Background Art

[0002] Mercury cadmium telluride is a nearly ideal infrared detector material with high absorption coefficient, high quantum efficiency, long carrier lifetime, high operating temperature, and can cover infrared radiation in the 1μm to 30μm band by adjusting the composition. In addition, mercury cadmium telluride also has the characteristics of adjustable carrier concentration, high electron mobility and low dielectric constant. In particular, as the composition changes, the lattice constant remains almost unchanged, which is very suitable for the preparation of composite films with complex structures such as multilayer heterostructures. Mercury cadmium telluride can be used to develop various types of detectors, such as photoconductive, photovoltaic and MIS detectors, forming a full range of detectors covering various specifications and applications in the near-infrared, short-wave, medium-wave, long-wave and very long-wave infrared bands, supporting the entire modern infrared technology system from the first to the third generation.

[0003] During the performance test of the mercury cadmium telluride infrared detector chip, the mercury cadmium telluride infrared detector chip will crack after a series of liquid nitrogen shocks. Further research found that the bottom of the mercury cadmium telluride infrared detector chip is often filled with colloid to fix and maintain the stability of the device. In actual operation, bubbles will be generated due to the flow of colloid. The number and size of the bubbles will affect the test process, causing the mercury cadmium telluride infrared detector chip to crack.

[0004] It should be noted that the information disclosed in the background technology section of the invention is only intended to deepen the understanding of the general background technology of the invention, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0005] The object of the present invention is to provide a monitoring method for a mercury cadmium telluride infrared detector chip, so as to solve the problem of bubbles and cracks in the mercury cadmium telluride infrared detector chip.

[0006] In order to solve the above technical problems, the present invention provides a monitoring method for a mercury cadmium telluride infrared detector chip, comprising:

[0007] Provide the chip to be tested;

[0008] The chip to be tested is corroded in an HCl solution to remove the covering layer thereon;

[0009] A solution is prepared by using hydrobromic acid and bromine in a certain proportion, and the chip to be tested is immersed in the solution to remove the mercury cadmium telluride material layer.

[0010] Preferably, the covering layer is made of zinc sulfide.

[0011] Preferably, the chip to be tested is corroded in HCl solution for 5 seconds.

[0012] Preferably, the ratio of hydrobromic acid to bromine is from 1:1 to 20:1.

[0013] Preferably, the ratio of hydrobromic acid to bromine is 10:1.

[0014] Preferably, a solution prepared by using hydrobromic acid and bromine in a certain ratio is used to immerse the chip to be tested for 10 minutes to remove the mercury cadmium telluride material layer.

[0015] Preferably, the chip to be tested is placed in a basket, and then immersed in a solution prepared by hydrobromic acid and bromine, and the chip to be tested is shaken.

[0016] In the monitoring method of the mercury cadmium telluride infrared detector chip provided by the present invention, the covering layer on the surface of the chip to be tested is removed by corrosion with an HCl solution, and then the mercury cadmium telluride material layer in the chip to be tested is removed. This not only avoids strong impact that causes bubbles in the bottom filling layer to cause the chip to be tested to crack, but also the bottom filling layer will not be damaged when the material layers are immersed and removed, and the natural condition of the filling bubbles can be directly observed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0018] Figure 1 is an execution flow chart of an embodiment of the present invention;

[0019] Figure 2 is a schematic diagram of a chip structure according to an embodiment of the present invention;

[0020] Figure 3 is a schematic diagram of the structure after removing the covering layer according to an embodiment of the present invention;

[0021] Figure 4 It is a schematic diagram of the bottom filling layer structure of an embodiment of the present invention.

[0022] In the attached figure:

[0023] 100, circuit layer; 200, bottom filling glue layer; 300, mercury cadmium telluride material layer; 400, covering layer. DETAILED DESCRIPTION

[0024] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0025] As used in the present invention, the singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or at least two of the features. The term "proximal end" is usually the end close to the operator, and the term "distal end" is usually the end close to the patient. "One end" and "the other end" as well as "proximal end" and "distal end" usually refer to two corresponding parts, which include not only the endpoints. The terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of the two elements or the interaction relationship between the two elements. In addition, as used in the present invention, an element is arranged on another element, which usually only means that there is a connection, coupling, matching or transmission relationship between the two elements, and the connection, coupling, matching or transmission between the two elements can be direct or indirect through an intermediate element, and it cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any position such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The inventors have found that bubbles may be generated during the filling process due to the flow of the bottom filling glue. During subsequent tests, the mercury cadmium telluride infrared detector chip is subjected to a series of liquid nitrogen shocks, and the bubbles in the bottom filling glue layer are very likely to explode, causing the mercury cadmium telluride infrared detector chip to crack.

[0027] Based on this, the core idea of ​​the present invention is to use HCl solution to remove the covering layer 400 on the chip to be tested, so as to avoid the covering layer 400 from reacting with the solution used subsequently, and the bottom filling layer 200 will not react with the HCl solution either, so as to facilitate the observation and monitoring of the bubble distribution in the bottom filling layer 200.

[0028] For details, please refer to Figure 1-Figure 4 , which is a schematic diagram of an embodiment of the present invention. Figure 1 As shown, a method for monitoring a mercury cadmium telluride infrared detector chip comprises:

[0029] S1, provide the chip to be tested, such as Figure 2 The chip under test structure shown in the figure generally includes a bottom circuit layer 100 , an underfill layer 200 , a mercury cadmium telluride material layer 300 and a cover layer 400 .

[0030] S2, corroding the chip to be tested in HCl solution to remove the covering layer 400 thereon, such as Figure 3 As shown, specifically, the material of the covering layer 400 is zinc sulfide.

[0031] The chip to be tested is placed in an HCl solution to remove the zinc sulfide material and other impurities on the surface of the chip to be tested. If the chip to be tested is directly placed in a corrosion solution to remove the mercury cadmium telluride material layer 300 without being treated with the HCl solution, not only will the mercury cadmium telluride material layer 300 on the chip to be tested fail to be removed, but when the proportion of the corrosion solution is too low, ZnS and HBr will react to produce sulfur-containing compounds. Br2 has strong oxidizing properties and will directly replace the sulfur in ZnS. The generated sulfur element is in the shape of a bottom fill bubble, which affects the monitoring of the bubbles in the bottom fill layer 200 of the mercury cadmium telluride infrared detector chip.

[0032] In one embodiment, the chip to be tested is corroded in an HCl solution for 5 seconds.

[0033] Since the underfill layer 200 does not react with the corrosive solution HCl solution, the underfill layer 200 will not be damaged, and the distribution of bubbles in the underfill layer 200 can be directly observed.

[0034] S3, using hydrobromic acid and bromine in a certain proportion to prepare a solution, soaking the chip to be tested to remove the mercury cadmium telluride material layer 300, such as Figure 4As shown, after the mercury cadmium telluride material layer 300 is removed, only the circuit layer 100 and the bottom fill layer 200 are left, and the distribution of bubbles in the bottom fill layer 200 can be directly observed. If the mercury cadmium telluride material layer 300 is placed upward in the solution, as the mercury cadmium telluride material layer 300 is removed, the top surface of the bottom fill layer 200 is also exposed, and the bubbles in the bottom fill layer 200 can also be directly observed in the solution. In the process of removing each material layer, the chip to be tested will not be cracked due to impact.

[0035] Specifically, a solution prepared by using hydrobromic acid and bromine in a certain ratio is used to immerse the chip to be tested for 10 minutes to remove the mercury cadmium telluride material layer 300 .

[0036] Exemplarily, the ratio of hydrobromic acid to bromine is 1:1 to 20:1. More preferably, the ratio of hydrobromic acid to bromine is 10:1.

[0037] It can be understood that the chip to be tested is placed in a basket, and then immersed in a solution of hydrobromic acid and bromine, and the chip to be tested is shaken. For example, the chip to be tested is placed in a basket made of corrosion-resistant material, such as a PTFE basket, and immersed in the solution for 10 minutes, and the chip to be tested is shaken during immersion to make the surface of the chip to be tested corroded evenly. In addition, a bubble generator or a stirring rod or other structures can be added to the container to disturb the solution and accelerate the corrosion of the surface material of the chip to be tested.

[0038] In the monitoring method of the mercury cadmium telluride infrared detector chip provided by the present invention, the chip to be tested is placed in an HCl solution for corrosion for 5 seconds, a corrosion solution with a ratio of hydrobromic acid to bromine of 1:1 to 20:1 is prepared, and the mercury cadmium telluride material layer 300 is corroded. The chip to be tested is placed in the corrosion solution using a PTFE basket and immersed for 10 minutes. During this period, the chip to be tested can be shaken up and down so that the surface of the chip to be tested is evenly corroded. Since the bottom filling layer 200 does not react with the corrosion solution and the HCl solution, the bottom filling layer 200 will not be damaged when other material layers are removed, which is helpful to directly observe the bubble situation in the bottom filling layer 200.

[0039] The chip to be tested is placed in an HCl solution to remove the zinc sulfide material and other impurities on the surface of the chip to be tested. If the chip to be tested is directly placed in a corrosion solution to remove the mercury cadmium telluride material layer 300 without being treated with the HCl solution, not only will the mercury cadmium telluride material layer 300 on the chip to be tested fail to be removed, but when the proportion of the corrosion solution is too low, ZnS and HBr will react to produce sulfur-containing compounds. Br2 has strong oxidizing properties and will directly replace the sulfur in ZnS. The generated sulfur element is in the shape of a bottom fill bubble, which affects the monitoring of the bubbles in the bottom fill layer 200 of the mercury cadmium telluride infrared detector chip.

[0040] The above description is only a description of the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for monitoring a mercury cadmium telluride infrared detector chip, characterized in that: include: Provide the chip to be tested; The chip to be tested is corroded in an HCl solution to remove the covering layer thereon; A solution is prepared by using hydrobromic acid and bromine in a certain proportion, and the chip to be tested is immersed in the solution to remove the mercury cadmium telluride material layer.

2. The monitoring method of the mercury cadmium telluride infrared detector chip according to claim 1, characterized in that: The material of the covering layer is zinc sulfide.

3. The monitoring method of the mercury cadmium telluride infrared detector chip according to claim 1, characterized in that: The chip to be tested was corroded in HCl solution for 5 seconds.

4. The monitoring method of the mercury cadmium telluride infrared detector chip according to claim 1, characterized in that: The ratio of hydrobromic acid to bromine is 1:1 to 20:

1.

5. The method for monitoring a mercury cadmium telluride infrared detector chip according to claim 4, characterized in that: The ratio of hydrobromic acid to bromine is 10:

1.

6. The method for monitoring a mercury cadmium telluride infrared detector chip according to claim 1, characterized in that: A solution prepared by using hydrobromic acid and bromine in a certain proportion is used to immerse the chip to be tested for 10 minutes to remove the mercury cadmium telluride material layer.

7. The method for monitoring a mercury cadmium telluride infrared detector chip according to claim 1, characterized in that: The chip to be tested is placed in a basket, and then immersed in a solution prepared by hydrobromic acid and bromine, and the chip to be tested is shaken.

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