Quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin film semiconductor material

Abstract

The invention relates to the technical field of thin film semiconductor material analysis, and particularly discloses a quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of a thin film semiconductor material. The method comprises the following steps: performing a failure environment simulation test on a sample by using an XPS in-situ illumination system and / or an XPS quasi-in-situ high-temperature gas reaction system; analyzing real-time / quasi-real-time surface chemical information of the sample in the environmental failure simulation process by using a surface analysis technology, and obtaining change rules of surface components, chemical states, electronic structures and interface structures of the sample; based on analysis of change rules of surface components, chemical states, electronic structures and interface structures of the samples, the failure mechanism of the samples under the action of the failure environment is obtained. The method aims at solving the problem that a traditional failure analysis method cannot analyze change rules of surface components, chemical states, electronic structures and interface structures in the failure process, and then basic technical support is provided for sample failure mode and failure mechanism analysis and sample design improvement.

Description

Technical Field

[0001] The present invention relates to the technical field of thin film semiconductor material analysis, and in particular to a quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin film semiconductor materials. Background Art

[0002] The application of thin film semiconductor materials covers electronic devices and equipment in all equipment industries. With the rapid development of space technology, they are also widely used in micro-electromechanical systems of aerospace and aviation devices, such as micro-intelligent integrated systems in the form of relays, brakes, radio frequency circuits and hybrid switches. During the use and storage of samples, the natural environmental factors (temperature, humidity, salt spray, precipitation, mold, dust, etc.) and induced environmental factors (mechanical factors, current, radiation effects, etc.) experienced by them will cause aging, corrosion and changes in internal stress of their own materials, resulting in performance degradation or even failure of the devices, leading to reduced reliability of use and storage of electronic components. The failure modes of thin film semiconductor materials and devices can be roughly divided into thermal overstress failure, electrical overstress failure, chip failure, packaging failure and other failures. Among them, thermal overstress failure and electrical overstress failure are the main failure modes of thin film semiconductor materials and devices. Thermal overstress can cause semiconductor failure, and excessive temperature can melt metal materials, carbonize and warp plastics, damage semiconductor chips, and cause other types of damage. The external cause of thermal stress in electronic components is the change in external temperature, which may come from two aspects: one is the change in the working or storage environment temperature of the electronic components. For example, the temperature difference of the ambient temperature at the storage location of the electronic components is very large, which is equivalent to a slow temperature cycle test on the electronic components; the second is that the temperature change experienced by the electronic components during welding and assembly causes the residual stress to be slowly released during the storage process, resulting in certain thermal stress in the electronic components. At the same time, as the size of electronic components continues to decrease, some harsh service conditions are imposed on the materials, such as high current intensity and corresponding high local temperature, which as internal factors can also cause thermal overstress failure of the materials. The electrical overstress failure is mainly caused by electromigration of the film during conduction. When the current flows through the semiconductor film, the electrons will collide with the metal atoms, causing the metal atoms to move, which in turn causes vacancies and component segregation inside the semiconductor film. Under the influence of these specific failure modes and the coupling of multiple failure modes, thin film semiconductor materials are prone to serious interdiffusion, resulting in significant changes in device performance, affecting the safe and normal operation of the electronic system and even the entire equipment system.

[0003] At present, the commonly used microscopic evaluation method for the research on the corrosion failure mechanism and corrosion failure protection of thin film semiconductor materials at home and abroad is mainly to use the measurement of electrical performance macroscopic parameters and scanning electron microscopy to observe the surface morphology and composition for judgment. However, the electrical performance macroscopic detection method is mostly used for analysis after the corrosion failure occurs, and the evaluation methods for this kind of failure are mostly at the macroscopic level, which is difficult to be used for early analysis of failure; and the scanning electron microscope can only observe the morphology after failure, which has hysteresis, and it is difficult to understand the failure process and the chemical reaction at the beginning of failure and the expansion of failure products. The research results show that the early failure of the material is related to the surface morphology of the material, and is also related to the surface composition and surface phenomena and interface conditions such as adsorption, segregation, and diffusion. In fact, the early failure basically occurs in the depth range of tens to more than one hundred nanometers on the surface of thin film semiconductor materials and devices, but the current failure evaluation methods are mostly based on the measurement and analysis of macroscopic parameters, which is difficult to accurately analyze and judge the surface state of materials and devices within the nanometer range. Summary of the invention

[0004] The purpose of the present invention is to propose a quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin-film semiconductor materials, aiming to solve the problem that traditional failure analysis methods are unable to analyze the microscopic composition and chemical state changes of the failure process, and further provide basic technical support for sample failure mode, failure mechanism analysis and sample design improvement.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin-film semiconductor materials, the method comprising the following steps:

[0007] Use XPS in-situ illumination system and / or XPS quasi-in-situ high-temperature gas reaction system to conduct failure environment simulation test on samples;

[0008] Use surface analysis technology to analyze the real-time / quasi-real-time surface chemical information of samples during failure environment simulation tests to obtain the surface composition, chemical state, electronic structure and interface structure change rules of the samples;

[0009] Based on the analysis of the changing laws of the sample's surface composition, chemical state, electronic structure and interface structure, the failure mechanism of the sample under the influence of the failure environment is obtained.

[0010] Preferably, the use of surface analysis technology to analyze the real-time / quasi-real-time surface chemical information of the sample during the failure environment simulation test includes: using an X-ray photoelectron spectrometer to analyze the sample;

[0011] Among them, the XPS in-situ illumination system is integrated in the analysis chamber of the X-ray photoelectron spectrometer, the XPS quasi-in-situ high-temperature gas reaction system is vacuum-connected to the analysis chamber of the X-ray photoelectron spectrometer, and the sample is transferred between the analysis chamber of the X-ray photoelectron spectrometer and the processing chamber of the XPS quasi-in-situ high-temperature gas reaction system through a vacuum transfer sample holder.

[0012] Preferably, the analyzing the sample by using an X-ray photoelectron spectrometer comprises:

[0013] Analyze the surface composition distribution, surface chemical state, surface electronic state and electronic band structure of the sample;

[0014] The atomic diffusion inside the sample, the interface component distribution, and the interface reaction products are analyzed.

[0015] Preferably, the failure environment simulation test performed on the sample using the XPS in-situ illumination system includes an ultraviolet light irradiation test and a visible light irradiation test.

[0016] Preferably, the failure environment simulation test of the sample performed using the XPS quasi-in-situ high-temperature gas reaction system includes heating treatment, environmental atmosphere reaction treatment, and direct current treatment.

[0017] Preferably, before performing a failure environment simulation test on the samples, samples with no quality defects in appearance are screened out based on the surface chemical information analysis results of the samples before the failure environment is applied.

[0018] Preferably, the method further comprises: checking whether the sample fails after being subjected to the failure environment, and preliminarily determining the failure mode.

[0019] The beneficial effects of the present invention are:

[0020] 1. This application is a systematic and comprehensive environmental failure analysis method, which can effectively analyze the potential failures of various thin-film semiconductor material devices, and has strong applicability and a wide range of applications.

[0021] 2. This application can complete customized failure conditions and environments according to the actual environment in which the finished device is used or the test stress application requirements of the device during the design process. It is flexible, diverse, adaptable, and highly operable. In addition, the external stress application device is vacuum-connected with the X-ray photoelectron spectrometer. During the external stress application process, the device can eliminate interference from other external factors and achieve quasi-in-situ analysis and detection, which provides stronger guidance and higher accuracy for the analysis of failure mechanisms.

[0022] 3. This application can provide strong support for improving device reliability and has unparalleled advantages in studying the environmental failure mechanism of devices. It can conduct a more comprehensive and in-depth analysis of finished devices before a large number of finished devices are put into use to discover potential defects and make improvements. In addition, this method can be used to conduct targeted experimental research during the device design process, shortening the device design and development cycle and reducing R&D costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flowchart of a method for analyzing the environmental failure mechanism of a sample provided in an embodiment of the present application.

[0024] Figure 2 It is a schematic diagram of the sample environmental failure mechanism analysis process of a quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin-film semiconductor materials provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0026] like Figure 1 and 2 As shown, a quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin-film semiconductor materials includes the following steps S1 to S3.

[0027] S1: Use the XPS in-situ illumination system and / or the XPS quasi-in-situ high-temperature gas reaction system to perform failure environment simulation tests on the samples.

[0028] In one embodiment of the present application, a thin film can be prepared on a semiconductor material by a thin film preparation method such as magnetron sputtering, wherein the process parameters (such as sputtering power, sputtering pressure, sputtering time, distance between the target material and the substrate, etc.) in the magnetron sputtering coating process can be regulated according to the target thickness of the film. In addition, a thin film can be prepared on a semiconductor material by a thin film preparation method such as vacuum evaporation, pulsed laser deposition, and molecular beam epitaxy. After the thin film is prepared, the semiconductor material with the thin film can be sliced ​​and sampled by a dicing machine and cut into a single sample with an area of ​​10mm×6mm.

[0029] In one embodiment of the present application, the XPS in-situ illumination system is integrated into the analysis chamber of the X-ray photoelectron spectrometer, and the processing chamber of the XPS quasi-in-situ high-temperature gas reaction system is connected to the analysis chamber of the X-ray photoelectron spectrometer by vacuum. The sample is moved between the processing chamber of the XPS quasi-in-situ high-temperature gas reaction system and the analysis chamber of the X-ray photoelectron spectrometer by vacuum transfer sample holder.

[0030] In one embodiment of the present application, the XPS in-situ illumination system can be used to perform ultraviolet light irradiation tests, visible light irradiation tests and other light failure environment simulation tests on the sample; the XPS quasi-in-situ high-temperature gas reaction system can be used to perform heating treatment, environmental atmosphere reaction treatment, direct current treatment and other failure environment simulation tests on the sample. For example: to study the effect of ultraviolet radiation in the outer space environment on aerospace thin film semiconductor devices, ultraviolet radiation should be applied to the sample to study the effects of different irradiation intensities and times; to study the effect of thermal effects on the device, the device can be heated to study the effect of the sample temperature on the internal element distribution in different environmental atmospheres, etc.

[0031] In addition, more devices interconnected with the X-ray photoelectron spectrometer (such as a humidifying device, a salt spray generating device, etc.) may be added to simulate multiple types of environmental failure factors.

[0032] S2: Use surface analysis technology to analyze the real-time / quasi-real-time surface chemical information of samples during failure environment simulation tests to obtain the surface composition, chemical state, electronic structure and interface structure change patterns of the samples.

[0033] The method of analyzing the real-time / quasi-real-time surface chemical information of the sample during the failure environment simulation test by using the surface analysis technology includes: analyzing the sample by using an X-ray photoelectron spectrometer.

[0034] Furthermore, the analysis of the sample using an X-ray photoelectron spectrometer includes: analyzing the surface component distribution, surface chemical state and surface electronic state of the sample; using ultraviolet photoelectron spectroscopy (UPS) and inverse photoelectron spectroscopy (IPES) to analyze the electronic band structure of the sample; using angle-resolved depth analysis method and ion etching depth analysis method to analyze the atomic diffusion, interface component distribution and interface reaction products inside the sample.

[0035] In one embodiment of the present application, samples without quality defects such as pinholes, burrs, islands, cracks, silicon dust, etc. in appearance can be first screened out based on the surface chemical information analysis results such as the surface composition, chemical state, electronic structure and interface structure of the samples before the failure environment, and then a failure environment simulation test can be performed on the screened samples.

[0036] In one embodiment of the present application, after the sample is taken out from the X-ray photoelectron spectrometer, it can be checked whether the sample has failed after being subjected to the failure environment, and the failure mode can be preliminarily determined.

[0037] S3: Based on the analysis of the surface composition, chemical state, electronic structure and interface structure change rules of the samples, the failure mechanism of the samples under the influence of the failure environment is obtained.

[0038] The solution of the present application is further described below through specific embodiments.

[0039] Taking Au / Ni / Cu / HfO2 thin film semiconductor materials as the research object, the physical and chemical adsorption caused by direct exposure of samples to air after conventional environmental failure treatment is not conducive to the semi-quantitative and qualitative analysis of the surface O element; especially when the bulk Cu atoms diffuse to the sample surface, they are easy to react with atmospheric oxygen and water vapor, and their true valence information cannot be obtained during XPS analysis. This application combines the XPS quasi-in-situ high-temperature gas reaction system with the quasi-in-situ XPS analysis technology to analyze the change law of the surface composition of the material by heating and introducing oxygen and nitrogen respectively, and analyzes the relative atomic concentration of the surface O element, Cu element and Ni element relative to the concentration ratio of the surface Au element. The quasi-in-situ X-ray photoelectron spectroscopy analysis method of this application can accurately analyze the real-time composition and valence information of the surface elements of the sample, and then can accurately study the influence mechanism of adsorbed oxygen on the film layer structure of the thin film, thereby revealing its diffusion mechanism.

[0040] The quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin-film semiconductor materials in the present application can conduct a systematic and comprehensive analysis of the potential failures of various types of thin-film semiconductor material devices, and has strong applicability and a wide range of applications. The present application can complete customized failure conditions and environments according to the actual environment in which the finished device is used or the test stress application requirements of the device during the design process. It is flexible, diverse, highly adaptable, and highly operable. Moreover, the external stress application device is vacuum-connected with the X-ray photoelectron spectrometer, and the device can eliminate interference from other external factors during the external stress application process, achieving quasi-in-situ analysis and detection, and providing stronger guidance and higher accuracy for the analysis of failure mechanisms.

[0041] In addition, this application can provide strong support for improving device reliability, and has an unparalleled advantage in studying the environmental failure mechanism of devices. It can conduct a more comprehensive and in-depth analysis of finished devices before a large number of them are put into use to discover potential defects and make improvements. In addition, this method can be used to conduct targeted experimental research during the device design process, shortening the device design and development cycle and reducing R&D costs.

[0042] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin film semiconductor materials, characterized in that: The method comprises the following steps: Use XPS in-situ illumination system and / or XPS quasi-in-situ high-temperature gas reaction system to conduct failure environment simulation test on samples; Use surface analysis technology to analyze the real-time / quasi-real-time surface chemical information of samples during failure environment simulation tests, and obtain the surface composition, chemical state, electronic structure and interface structure change rules of the samples; Based on the analysis of the changing laws of the sample's surface composition, chemical state, electronic structure and interface structure, the failure mechanism of the sample under the influence of the failure environment is obtained.

2. The quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin film semiconductor materials according to claim 1, characterized in that: The use of surface analysis technology to analyze the real-time / quasi-real-time surface chemical information of the sample during the failure environment simulation test includes: using an X-ray photoelectron spectrometer to analyze the sample; Among them, the XPS in-situ illumination system is integrated in the analysis chamber of the X-ray photoelectron spectrometer, the XPS quasi-in-situ high-temperature gas reaction system is vacuum-connected to the analysis chamber of the X-ray photoelectron spectrometer, and the sample is transferred between the analysis chamber of the X-ray photoelectron spectrometer and the processing chamber of the XPS quasi-in-situ high-temperature gas reaction system through a vacuum transfer sample holder.

3. The quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin film semiconductor materials according to claim 2, characterized in that: The analysis of the sample by using an X-ray photoelectron spectrometer comprises: Analyze the surface composition distribution, surface chemical state, surface electronic state and electronic band structure of the sample; The atomic diffusion inside the sample, the interface component distribution, and the interface reaction products are analyzed.

4. The quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin film semiconductor materials according to claim 1, characterized in that: The failure environment simulation tests on samples conducted using the XPS in-situ illumination system include ultraviolet light irradiation tests and visible light irradiation tests.

5. The quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin film semiconductor materials according to claim 1, characterized in that: The failure environment simulation test of the samples conducted using the XPS quasi-in-situ high-temperature gas reaction system includes heating treatment, environmental atmosphere reaction treatment, and direct current treatment.

6. The quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin film semiconductor materials according to claim 1, characterized in that: Before conducting failure environment simulation tests on samples, samples with no quality defects in appearance are screened out based on the surface chemical information analysis results of the samples before the failure environment is applied.

7. The quasi-in-situ X-ray photoelectron spectroscopy analysis method for environmental failure of thin film semiconductor materials according to claim 1, characterized in that: The method further comprises: checking whether the sample fails after being subjected to the failure environment, and preliminarily determining the failure mode.

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