阅读说明：本技术 碲镉汞钝化膜层工艺参数确定方法及装置 (Method and device for determining technological parameters of tellurium-cadmium-mercury passivation film layer ) 是由 祁娇娇 宁提 谭振 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种碲镉汞钝化膜层工艺参数确定方法及装置,所述方法包括：分别将膜层沉积系统的各工艺参数作为唯一变量,在衬底溅射一层或多层化学膜层；对所述化学膜层进行折射率测试,获取所述化学膜层的折射率随各工艺参数的变化曲线,并根据所述变化曲线获取所述化学膜层的折射率最大点对应的各个工艺参数的数值；将所述数值作为膜层沉积系统沉积所述化学膜层时的工艺参数。(The invention discloses a method and a device for determining technological parameters of a mercury cadmium telluride passivation film layer, wherein the method comprises the following steps: sputtering one or more chemical film layers on a substrate by taking each process parameter of a film layer deposition system as a unique variable; testing the refractive index of the chemical film layer to obtain a variation curve of the refractive index of the chemical film layer along with each process parameter, and obtaining the numerical value of each process parameter corresponding to the maximum refractive index of the chemical film layer according to the variation curve; and taking the numerical value as a process parameter when the film deposition system deposits the chemical film.)

1. A method for determining technological parameters of a mercury cadmium telluride passivation film layer is characterized by comprising the following steps:

sputtering one or more chemical film layers on a substrate by taking each process parameter of a film layer deposition system as a unique variable;

testing the refractive index of the chemical film layer to obtain a variation curve of the refractive index of the chemical film layer along with each process parameter, and obtaining the numerical value of each process parameter corresponding to the maximum refractive index of the chemical film layer according to the variation curve;

and taking the numerical value as a process parameter when the film deposition system deposits the chemical film.

2. The method of claim 1, wherein the method further comprises:

setting a film deposition system according to the determined process parameters, and depositing a chemical film on the substrate through the film deposition system;

and carrying out multi-point refractive index test on the chemical film layer, and determining the thickness uniformity and the density uniformity of the chemical film layer according to the obtained multi-point refractive index.

3. The method of claim 1 or 2, wherein the film layer deposition system comprises: a magnetron sputtering system; the chemical film layer specifically includes: cadmium telluride CdTe and/or zinc sulfide ZnS.

4. The method of claim 1, wherein the substrate is an opaque semiconductor material, the opaque semiconductor material being one of: a silicon chip, a tellurium-zinc-cadmium substrate and a tellurium-cadmium-mercury epitaxial material.

5. The method of claim 1, wherein performing a refractive index test on the chemical film layer specifically comprises:

and (3) performing a refractive index test on the chemical film layer by using an elliptical deflection device or a spectrophotometer.

6. A tellurium cadmium mercury passivation film layer process parameter determination device is characterized by comprising the following steps:

the variable module is used for sputtering one or more chemical film layers on the substrate by taking each process parameter of the film layer deposition system as a unique variable;

the refractive index calculation module is used for testing the refractive index of the chemical film layer, acquiring a change curve of the refractive index of the chemical film layer along with each process parameter, and acquiring the numerical value of each process parameter corresponding to the maximum refractive index point of the chemical film layer according to the change curve;

and the setting module is used for taking the numerical value as a process parameter when the film deposition system deposits the chemical film.

7. The apparatus of claim 6,

the variable module is further to: setting a film deposition system according to the determined process parameters, and depositing a chemical film on the substrate through the film deposition system;

the refractive index calculation module is further configured to: and carrying out multi-point refractive index test on the chemical film layer, and determining the thickness uniformity and the density uniformity of the chemical film layer according to the obtained multi-point refractive index.

8. The apparatus of claim 6 or 7, wherein the film layer deposition system comprises: a magnetron sputtering system; the chemical film layer specifically includes: cadmium telluride CdTe and/or zinc sulfide ZnS.

9. The apparatus of claim 6, wherein the substrate is an opaque semiconductor material, the opaque semiconductor material being one of: a silicon chip, a tellurium-zinc-cadmium substrate and a tellurium-cadmium-mercury epitaxial material.

10. The method of claim 6, wherein the refractive index calculation module is specifically configured to:

and (3) performing refractive index test on the CdTe and/or ZnS film layer by using an elliptical offset device or a spectrophotometer.

Technical Field

The invention relates to the field of infrared detector devices, in particular to a method and a device for determining technological parameters of a mercury cadmium telluride passivation film layer.

Background

In the preparation process of the mercury cadmium telluride infrared detector, a CdTe/ZnS double-layer film system is mostly adopted for material surface passivation, and the CdTe/ZnS double-layer film system plays a role in masking, protecting and shielding the material surface. Currently, CdTe/ZnS can be deposited by magnetron sputtering, anodic oxidation, evaporation and other modes, and the quality of a passivation layer has a direct influence on the surface electric leakage and other electrical properties of a device.

For the quality of the passivation layer, the tellurium-cadmium-mercury production line has no direct evaluation standard, and an evaluation system is urgently needed to be established for the passivation layer on the tellurium-cadmium-mercury surface in order to directly and conveniently guide the process. And the setting of the process parameters of the magnetron sputtering system is guided according to the evaluation method.

Disclosure of Invention

The embodiment of the invention provides a method and a device for determining technological parameters of a mercury cadmium telluride passivation film layer, which are used for solving the problems in the prior art.

The embodiment of the invention provides a method for determining technological parameters of a mercury cadmium telluride passivation film layer, which comprises the following steps:

sputtering one or more chemical film layers on a substrate by taking each process parameter of a film layer deposition system as a unique variable;

testing the refractive index of the chemical film layer to obtain a variation curve of the refractive index of the chemical film layer along with each process parameter, and obtaining the numerical value of each process parameter corresponding to the maximum refractive index of the chemical film layer according to the variation curve;

and taking the numerical value as a process parameter when the film deposition system deposits the chemical film.

The embodiment of the invention also provides a device for determining the technological parameters of the mercury cadmium telluride passivation film layer, which comprises the following components:

the variable module is used for sputtering one or more chemical film layers on the substrate by taking each process parameter of the film layer deposition system as a unique variable;

the refractive index calculation module is used for testing the refractive index of the chemical film layer, acquiring a change curve of the refractive index of the chemical film layer along with each process parameter, and acquiring the numerical value of each process parameter corresponding to the maximum refractive index point of the chemical film layer according to the change curve;

and the setting module is used for taking the numerical value as a process parameter when the film deposition system deposits the chemical film.

By adopting the embodiment of the invention, the process parameters of the film deposited by the magnetron sputtering system are confirmed through the evaluation of the refractive index on the passivation film, the density of the passivation film is improved, and the surface leakage of the mercury cadmium telluride infrared detector is reduced.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a schematic diagram of a method for determining process parameters of a mercury cadmium telluride passivation film layer according to an embodiment of the invention;

FIG. 2 is a schematic diagram of a refractive index test of a surface passivation layer of a mercury cadmium telluride material according to an embodiment of the invention;

FIG. 3 is a schematic representation of the change in refractive index of a CdTe film layer versus sputtering power for an embodiment of the invention;

FIG. 4 is a schematic illustration of the refractive index of a CdTe film layer versus process pressure variation for an embodiment of the invention;

fig. 5 is a schematic diagram of a device for determining process parameters of a mercury cadmium telluride passivation film layer according to an embodiment of the invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

According to the embodiment of the invention, the method for determining the technological parameters of the mercury cadmium telluride passivation film layer is provided,

the passivation film layer deposited on the surface of the mercury cadmium telluride material has an effect of inhibiting electric leakage on the surface of a device, and the effect of inhibiting the electric leakage by the passivation film layer can be increased by improving the density of the passivation film layer. The CdTe material is a commonly used semiconductor infrared thin film material and has good infrared optical characteristics, and the light transmission area of the CdTe material is 0.97-31 mu m; the ZnS material is a fluorescent material and has good permeability in visible light and infrared light regions. Based on the optical characteristics of the two materials, the refractive index can be used as an important parameter for evaluating the quality of the CdTe and ZnS material film layer, and the higher the density of the film layer is, the higher the concentration density of the film material molecules is, the higher the refractive index of the film is. Based on the above analysis, the passivation film layer can be evaluated according to the following points:

1. the refractive index of the film layer can be tested by using equipment such as an elliptical offset spectrophotometer and the like;

2. for the mercury cadmium telluride material surface passivation film layer, the refractive index test can be carried out on a single-layer film, and the refractive index test can also be carried out on a double-layer film;

specifically, the single-layer film test mode may be to perform the refractive index test after depositing a single CdTe film layer or ZnS film layer on a silicon wafer, a CdTe substrate, a CdTe-hg epitaxial material, or other opaque semiconductor material as a substrate.

The double-layer film test mode can be that a silicon chip, a tellurium-zinc-cadmium substrate, a tellurium-cadmium-mercury epitaxial material or other opaque semiconductor materials are used as the substrate, and the refractive index test is carried out after a CdTe/ZnS double-layer passivation film layer is deposited on the substrate;

3. for the tellurium-cadmium-mercury material without photoetching patterns, the passivation layer on the surface of the material can be directly tested;

4. for the tellurium-cadmium-mercury material with photoetching pictures, a passivation film layer test block can be added in the first step of photoetching process and is used for testing the refractive index of the passivation film layer.

5. The thickness and uniformity of the surface passivation film layer can be evaluated by using a refractive index multi-point test method.

Based on the above analysis, the following describes technical solutions of embodiments of the present invention with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of a method for determining a process parameter of a mercury cadmium telluride passivation film layer according to an embodiment of the present invention, and as shown in fig. 1, the method for determining a process parameter of a mercury cadmium telluride passivation film layer according to an embodiment of the present invention specifically includes:

step 101, sputtering one or more chemical film layers, such as a cadmium telluride (CdTe) film layer and/or a zinc sulfide (ZnS) film layer, on a substrate by respectively taking each process parameter of a film layer deposition system (such as a magnetron sputtering system) as a unique variable; the substrate is made of an opaque semiconductor material, and the opaque semiconductor material is specifically one of the following materials: a silicon chip, a tellurium-zinc-cadmium substrate and a tellurium-cadmium-mercury epitaxial material.

102, testing the refractive index of the chemical film layer to obtain a variation curve of the refractive index of the chemical film layer along with each process parameter, and obtaining the numerical value of each process parameter corresponding to the maximum refractive index point of the chemical film layer according to the variation curve; preferably, the chemical film layer may be subjected to a refractive index test using an ellipsometric apparatus or a spectrophotometer.

And 103, taking the numerical value as a process parameter when the film deposition system deposits and is chemically ground.

Preferably, after step 103 is executed, the following process may be further performed:

step 1, setting a film deposition system according to the determined process parameters, and depositing a chemical film on a substrate through the film deposition system;

and 2, carrying out multi-point refractive index test on the chemical film layer, and determining the thickness uniformity and the density uniformity of the chemical film layer according to the obtained multi-point refractive index.

In an embodiment of the present invention, the film deposition system includes: a magnetron sputtering system; the chemical film layer specifically includes: cadmium telluride CdTe and/or zinc sulfide ZnS.

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention. For the purpose of clarity and simplicity, a detailed description of known functions and configurations in the devices described herein will be omitted when it may obscure the subject matter of the present invention.

In order to improve the density of the mercury cadmium telluride surface passivation film layer, improve the quality of the passivation film layer and better inhibit the surface leakage of the mercury cadmium telluride infrared detector, the embodiment of the invention provides an evaluation method of the mercury cadmium telluride surface passivation layer, and the invention is further described in detail with reference to the attached drawings and a plurality of embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.

In the embodiment of the invention, the refractive index is used for evaluating the CdTe film layer of the magnetron sputtering substrate and guiding the improvement of the density of the CdTe film layer of the magnetron sputtering system. Growing a CdTe single-layer film layer on a silicon wafer serving as a substrate under different process conditions, and performing a refractive index test by using elliptical migration, wherein the wavelength of a light source is 0.3-0.8 micron.