Method for judging passivation quality of passivation film and tellurium-cadmium-mercury chip

Abstract

The invention provides a method for judging the passivation quality of a passivation film and a mercury cadmium telluride chip, and belongs to the field of semiconductors. The method for judging the passivation quality of the passive film comprises the steps that the passive film is placed in corrosive liquid at the set temperature, soaking is conducted for the set time, the corrosion condition of the passive film is observed, when the surface of the passive film is free of loss, the passive film is judged to be qualified, otherwise, the passive film is judged to be unqualified, and the corrosive liquid is alkali liquor or mixed liquor of the alkali liquor and hydrogen peroxide. According to the method, the passive film is placed in the corrosive liquid at the set temperature, soaking is conducted for the set time, the corrosion condition of the passive film is observed, when the surface of the passive film is free of loss, it is judged that the passive film is qualified, otherwise, the passive film is unqualified, and the corrosive liquid is alkali liquor or mixed liquor of the alkali liquor and hydrogen peroxide; and the influence of human factors on passivation quality judgment of the passivation film can be eliminated. By observing the condition that the passive film is corroded by the corrosive liquid, the phenomenon is visual, the test result is obvious, the quality of the passive film can be more directly indicated, and the test result is accurate.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductors, and in particular to a method for judging the passivation quality of a passivation film and a mercury cadmium telluride chip. Background Art

[0002] Mercury cadmium telluride is an important material for preparing infrared detectors. Due to its adjustable bandgap width, the detection spectrum range extends from the shortwave band to the very long wave band. It has the advantages of high photoelectric detection efficiency and is widely used in military and civil fields such as early warning detection, infrared reconnaissance, and imaging guidance.

[0003] Usually, a passivation film is set on the surface of the mercury cadmium telluride chip, for example, zinc sulfide material is used to form a coating on the surface of the mercury cadmium telluride chip, covering the surface of the chip, which plays a role in reducing surface recombination, improving chip stability, insulation, etc. In order to ensure the stable performance of the chip, after the passivation film containing zinc sulfide material is formed, the passivation quality of the passivation film needs to be tested.

[0004] In the prior art, in order to detect the passivation quality of the passivation film, a tape pulling method is generally used, that is, the passivation film is pasted with tape and traditional physical pulling is used to provide feedback on the adhesion of the passivation film, thereby indirectly judging the film quality of the passivation film. However, the adhesion cannot fully represent the film quality of the passivation film, and is affected by factors such as the adhesion of the tape and the pulling force, which may lead to errors in the evaluation results.

[0005] 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

[0006] The purpose of the present invention is to provide a method for judging the passivation quality of a passivation film and a mercury cadmium telluride chip, so as to solve the problem of judgment error when judging the passivation quality of a passivation film due to the influence of factors such as tape adhesion and pulling force.

[0007] In order to solve the above technical problems, the present invention provides a method for judging the passivation quality of a passivation film, comprising:

[0008] The passivation film is placed in a corrosive solution at a set temperature, immersed for a set time, and the corrosion of the passivation film is observed. When there is no loss on the surface of the passivation film, the passivation film is judged to be qualified, otherwise it is unqualified, wherein the corrosive solution is an alkali solution, or a mixture of an alkali solution and hydrogen peroxide.

[0009] Preferably, the corrosive liquid is an alkaline solution, and the mass fraction of the alkaline solution is 50%.

[0010] Preferably, the corrosive liquid is a mixture of alkali solution and hydrogen peroxide, wherein the volume ratio of the alkali solution to the hydrogen peroxide is 20:1 to 30:1.

[0011] Preferably, the etching solution is set at 80-100° C. by heating in a water bath.

[0012] Preferably, the passivation film is immersed in the corrosive solution for 10 to 30 minutes.

[0013] Preferably, the passivation film is a coating formed by zinc sulfide material on the chip surface.

[0014] Preferably, the alkali solution is potassium hydroxide solution.

[0015] Based on the same inventive concept, the present invention also provides a mercury cadmium telluride chip, comprising:

[0016] A passivation film is grown on the surface of the chip;

[0017] The passivation quality of the passivation film is determined by the method for determining the passivation quality of the passivation film as described above.

[0018] Preferably, the material of the passivation film is zinc sulfide.

[0019] Preferably, a passivation film is grown on the surface of the mercury cadmium telluride chip by chemical deposition.

[0020] Compared with the prior art, the method for judging the passivation quality of the passivation film of the present invention has the following advantages:

[0021] The present invention places the passivation film in a corrosive solution at a set temperature, soaks for a set time, observes the corrosion of the passivation film, and judges that the passivation film is qualified when there is no loss on the surface of the passivation film, otherwise it is unqualified, wherein the corrosive solution is an alkaline solution, or a mixture of an alkaline solution and hydrogen peroxide, which can eliminate the influence of human factors on the passivation quality judgment of the passivation film. By observing the corrosion of the passivation film by the corrosive solution, the phenomenon is intuitive, the test result is significant, and the quality of the passivation film is more directly explained, and the test result is accurate.

[0022] The mercury cadmium telluride chip provided by the present invention and the method for judging the passivation quality of the passivation film provided by the present invention belong to the same inventive concept. Therefore, the mercury cadmium telluride chip provided by the present invention at least has all the advantages of the method for judging the passivation quality of the passivation film provided by the present invention, can intuitively judge the quality of the passivation film, the judgment result is accurate, and the stability of the performance of the mercury cadmium telluride chip is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of using the tape pulling method to judge the passivation quality of the passivation film;

[0024] Figure 2 It is a schematic diagram of the structure in which the passivation film is pulled off by the tape pulling method;

[0025] Figure 3 This is a schematic diagram of the structure in which the passivation film is not pulled off by the tape pulling method;

[0026] Figure 4 This is a real picture of the passivation film being pulled by the tape pulling method;

[0027] Figure 5 It is a structural schematic diagram of a method for judging the passivation quality of a passivation film in one embodiment of the present invention;

[0028] Figure 6 Is adopted Figure 5 The judgment method in the diagram, the schematic diagram of the structure of the corrosion of the passive film surface;

[0029] Figure 7 Is adopted Figure 5 The judgment method in the figure shows the structure diagram of the passive film surface that is not corroded;

[0030] Figure 8 Is adopted Figure 5 The judgment method in the text, the actual picture of the corrosion on the surface of the passivation film;

[0031] Fig. 9 Is adopted Figure 5 The judgment method in the figure shows that the surface of the passivation film is not corroded;

[0032] In the figure,

[0033] 10-substrate; 20-passivation layer;

[0034] 30-tape; 100-substrate;

[0035] 200-passivation film; 300-corrosive solution;

[0036] 400-Container. DETAILED DESCRIPTION

[0037] In order to make the purpose, advantages and features of the present invention clearer, the method for judging the passivation quality of the passivation film and the mercury cadmium telluride chip proposed by the present invention are further described in detail in combination with the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. It should be understood that the drawings in the specification do not necessarily show the specific structure of the present invention in proportion, and the illustrative features used to illustrate certain principles of the present invention in the drawings in the specification will also adopt a slightly simplified drawing method. The specific design features of the present invention disclosed herein include, for example, specific dimensions, directions, positions and shapes, which will be determined in part by the specific environment to be applied and used. And, in the embodiments described below, sometimes the same figure mark is used in common between different drawings to represent the same part or the part with the same function, and its repeated description is omitted. In this specification, similar numbers and letters are used to represent similar items, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0039] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0040] Ginseng Figures 1 to 4 As shown, the substrate 10 can be a chip of mercury cadmium telluride material. In order to improve the chip stability, insulation and other reasons, a passivation layer (i.e., passivation film) 20 is formed on the surface of the chip. In the prior art, the passivation quality of the passivation layer 20 is judged by a tape pulling method. Figure 1 As shown, the tape 30 is pasted on the passivation layer 20, wherein the tape 30 is a 3M tape. Figure 1In the direction indicated by the arrow, the tape 30 is manually pulled. The passivation layer 20 is observed to see if it is damaged. Figure 2 When the surface of the passivation layer 20 is damaged as shown in FIG. Figure 3 In the structure shown in FIG. 1 , the surface of the passivation layer 20 is not damaged. This indicates that the passivation quality of the passivation layer 20 is qualified. Figure 4 As shown, Figure 4 The following are actual pictures of the passivation layer 20 being pulled by the tape pulling method, wherein Figure (4a) shows the substrate 10 before pulling, and Figure (4b) shows the substrate 10 after pulling. Figure 4 It can be seen that the surface of the substrate 10 is not damaged after being pulled, indicating that the passivation layer 20 on the surface of the substrate 10 is of qualified quality. However, due to the difference in the adhesiveness of the tape and the influence of factors such as the artificial pulling force, the evaluation results may have errors.

[0041] The core idea of ​​the present invention is to provide a method for judging the passivation quality of a passivation film, which can avoid errors in the judgment results when judging the passivation quality of the passivation film.

[0042] In order to realize the above idea, the present invention provides a method for judging the passivation quality of the passivation film. Figures 5 to 9 A specific implementation of a method for judging the passivation quality of a passivation film disclosed. The method for judging the passivation quality of a passivation film comprises: placing a passivation film 200 in a corrosive solution 300 at a set temperature, soaking for a set time, observing the corrosion of the passivation film 200, and judging that the passivation film 200 is qualified when there is no loss on the surface of the passivation film 200, otherwise it is unqualified, wherein the corrosive solution 300 is an alkali solution, or a mixture of an alkali solution and hydrogen peroxide.

[0043] The passivation film 200 covers the substrate 100. The substrate 100, like the substrate 10 described above, can be a chip made of mercury cadmium telluride material.

[0044] Specifically, refer to Figures 5 to 9As shown, the material of the passivation film 200 is zinc sulfide material. The chip with the passivation film 200 is placed in a container 400, and the corrosive liquid 300 is added to the container 400. Next, the container 400 is heated, that is, in the case of water bath heating, the corrosion of the passivation film 200 is observed. When the temperature of the water bath heating is measured by a thermometer to 80-100°C, the heating is stopped. And the temperature of the corrosive liquid 300 is kept in the range of 80-100°C. The purpose of placing the chip in the corrosive liquid 300 during water bath heating is to enhance the corrosiveness of the passivation film 200. After the chip is immersed in the container 400 for 10 minutes to 30 minutes, the corrosion of the passivation film 200 on the surface of the chip is observed. If the passivation film 200 on the surface of the chip is damaged, the quality of the passivation film 200 is unqualified. If the quality of the passivation film 200 is not damaged, it means that the quality of the passivation film 200 is qualified. The chip can be immersed in the etching solution 300 for 10 minutes, 20 minutes, 30 minutes, or any time from 10 minutes to 30 minutes. In order to improve the quality of the passivation film 200 and the accuracy of the quality judgment of the passivation film 200, preferably, the chip is immersed in the etching solution 300 for 30 minutes.

[0045] The corrosive liquid 400 may be an alkali solution. The alkali solution may be an alkali solution such as a sodium hydroxide solution or a potassium hydroxide solution. In this embodiment, a potassium hydroxide solution is preferably used as the alkali solution. The mass fraction of the potassium hydroxide solution is 50%.

[0046] The corrosive liquid 300 may also be a mixture of alkali solution and hydrogen peroxide. The alkali solution is still preferably a potassium hydroxide solution. A potassium hydroxide solution with a mass fraction of 50% and a hydrogen peroxide with a mass fraction of 40% are mixed, and the volume ratio of the potassium hydroxide solution to the hydrogen peroxide is 20:1 to 30:1. That is, the volume ratio of the potassium hydroxide solution to the hydrogen peroxide can be 20:1, 25:1, 30:1, or any value within the range of 20:1 to 30:1.

[0047] In this embodiment, the passivation quality of the passivation film 200 is determined by placing the chip with the passivation film 200 in the etching solution 300 heated in a water bath for 10 to 30 minutes and observing whether the passivation film 200 is corroded. Figure 6 When the passivation film 200 is not damaged, that is, after being corroded by the corrosive liquid 300, the passivation film 200 is judged to be unqualified. Figure 7 As shown, if the passivation film 200 is intact, it is determined that the quality of the passivation film 200 is qualified. In addition, by observing the time when the passivation film 200 is damaged and the area of ​​the passivation film 200 that is damaged, the difference in the passivation quality of the passivation film 200 can be judged. The shorter the time when the passivation film 200 is damaged, or the larger the area of ​​the passivation film 200 that is damaged, the worse the passivation quality of the passivation film 200 is.

[0048] Furthermore, in order to improve the accuracy of judging the passivation quality of the passivation film 200, external tools can be used to observe the condition of the passivation film 200 after being corroded by the corrosive liquid 300. For example, after the passivation film 200 is corroded, it is difficult to judge with the naked eye whether the passivation film 200 is damaged. At this time, tools such as a magnifying glass can be used to observe whether the passivation film 200 is damaged.

[0049] In the actual passivation quality judgment of the passivation film 200, two chips with the passivation film 200 as shown in Figure (8a) and Figure (9a) are provided, and the two chips are placed in the etching solution 300 for 10 minutes to 30 minutes under 80-100°C water bath heating. It can be seen from the observation that there is damage at b on the surface of the passivation film 200 in Figure (8b), and from the area of ​​the damage, the passivation film 200 has multiple damages. Therefore, the passivation quality of the passivation film 200 is unqualified. Then, the passivation film 200 in Figure (9b) is not damaged, so the quality of the passivation film 200 in Figure (9b) is qualified. The method for judging the passivation quality of the passivation film provided in this embodiment can solve the technical problem that the judgment result has errors due to the difference in adhesiveness of the tape and the influence of factors such as the human pulling force. The influence of human factors is eliminated, the phenomenon is intuitive, and the test results are accurate. The test results are significant, which more directly illustrates the quality of the passivation film 200.

[0050] To realize the above idea, the embodiment also discloses a mercury cadmium telluride chip, including: growing a passivation film 200 on the surface of the chip. The passivation quality of the passivation film 200 is determined by the method for determining the passivation quality of the passivation film as described above. The material of the passivation film 200 is zinc sulfide. A passivation film 200 is grown on the surface of the mercury cadmium telluride chip by chemical deposition.

[0051] The mercury cadmium telluride chip provided in this embodiment and the method for judging the passivation quality of the passivation film provided in this embodiment belong to the same inventive concept. Therefore, the mercury cadmium telluride chip provided in this embodiment has at least all the advantages of the method for judging the passivation quality of the passivation film provided in this embodiment, can intuitively judge the quality of the passivation film, the judgment result is accurate, and the stability of the performance of the mercury cadmium telluride chip is ensured.

[0052] In summary, the above embodiments provide a detailed description of the method for judging the passivation quality of the passivation film and the different configurations of the mercury cadmium telluride chip. Of course, the above description is only a description of the preferred embodiments of the present invention, and is not any limitation to the scope of the present invention. The present invention includes but is not limited to the configurations listed in the above embodiments. Those skilled in the art can draw inferences based on the contents of the above embodiments. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A method for judging the passivation quality of a passivation film, characterized in that: include: The passivation film is placed in a corrosive solution at a set temperature, immersed for a set time, and the corrosion of the passivation film is observed. When there is no loss on the surface of the passivation film, the passivation film is judged to be qualified, otherwise it is unqualified, wherein the corrosive solution is an alkali solution, or a mixture of an alkali solution and hydrogen peroxide.

2. The method for judging the passivation quality of a passivation film according to claim 1, characterized in that: The corrosive liquid is an alkali liquid, and the mass fraction of the alkali liquid is 50%.

3. The method for judging the passivation quality of a passivation film according to claim 1, characterized in that: The etching solution is a mixture of alkali solution and hydrogen peroxide, wherein the volume ratio of the alkali solution to the hydrogen peroxide is 20:1 to 30:

1.

4. The method for judging the passivation quality of a passivation film according to claim 1, characterized in that: The etching solution is set at 80-100° C. by heating in a water bath.

5. The method for judging the passivation quality of a passivation film according to claim 1, characterized in that: The time for the passivation film to be immersed in the corrosive solution is 10 to 30 minutes.

6. The method for judging the passivation quality of a passivation film according to claim 1, characterized in that: The passivation film is a coating formed by zinc sulfide material on the surface of the chip.

7. The method for judging the passivation quality of a passivation film according to claim 1, characterized in that: The alkali solution is potassium hydroxide solution.

8. A mercury cadmium telluride chip, characterized in that: include: A passivation film is grown on the surface of the chip; The passivation quality of the passivation film is determined by using the method for determining the passivation quality of the passivation film as described in any one of claims 1 to 7.

9. The mercury cadmium telluride chip according to claim 8, characterized in that: The material of the passivation film is zinc sulfide.

10. The mercury cadmium telluride chip according to claim 8, characterized in that: A passivation film is grown on the surface of the mercury cadmium telluride chip by chemical deposition.

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