Electron Microscopy Of Microwave Semiconductor Devices Reliability Analysis

With the development of modern electronic technology and the high frequency of the work of electronic machine systems, the quality and reliability of microwave semiconductors decline the reliability of electronic machine systems and lead a great economic losses both the supplies and demands. How to further improve and strengthen microwave semiconductors reliability has already become a critical question receiving ever-increasing emphasis. This paper uses a scanning electronic microscope and an electron probe as the principal research method for conducting an electron microscopy analysis of microwave semiconductors reliability and has found the following results:(1) The preparation method for the reliability sample analysis of microwave semiconductors was conducted by different experimental goals and various methods. it should choose carbon If the observed majority is composed of an element, or choose Au when the observed majority is second-time electron micrograph, plating according to the different and various degrees of smoothness and growth multiples of the sample surface.(2) The method how to improve the quality of second electron image made by SEM. Use proper accelerating voltage for different samples. For experiment under high magnification, small size of spot size should be chosen. For experiment under low magnification, comparatively bigger size of spot size should be chosen. Conduction technology, lowering voltage technology and rapidly observing technology can be used to reduce charging effect, and the clearest image is obtained by multi-aspects adjustment.(3) The study on how to improve quantitative analysis results of sample by Energy-Dispersive Electron Microprobe. You should choose accelerating voltage, amplification and collection time to obtain accurate results. Spectrum analysis need calibration and you need choose different sample to calibrate. Finally it will make the interest area to cover the entire spectral peak. HPD technology could identify the overlapping peaks and be given quantitative analysis results.(4) The research and analysis of bonding between gold and aluminum. In the jointing process of Au and Al, the growth and decline of inter metallic compounds and the forming mechanism of cavity are the factors that determine the jointing strength of micro-contact and the reasons of why the gold-line would be stripped. The degeneration of shear strength has close relationship with the cavity forming degree. The forming of cavity would force the degeneration of bonding point, and finally form a complete cranny. The cranny will lead to the completely separation between Au-wire and Al-pad and thus failure. High temperature force the halogen elements ion reacted with Al. Instable aluminum halides are generated, and cavity forms on the inner face of Au and Au-Al layers, then welding spot will be fragile or open circuit. The element constitution of plastic packaging is one of the reasons of the device failure.(5) For the analysis of fail micro-wave semiconductor device, this paper discusses the main factor of the failure from theory and technology, and summarizes the main failure mode and the mechanism. Base on this, some practical improve methods are proposed for the problems, thus the same mistakes would be avoided in the designing and producing process.