Study On The Injury Mechanism Of Microwave LNA And Epitaxial Growth And Etching Technology Of SiC Films

This paper consists of two parts, Part 1 deals with the injury mechanism of microwave low noise amplifier (LNA) and Part 2 deals with the epitaxial growth and plasma etching technology of SiC Films.Semiconductor devices and integrated circuits have some weakness under the conditions of outside electrical stress, which can induce various kinds of injure effects and functional injury. Study on injury mechanism of microwave LNA is meant to search for an effective and skillful means to attack the key devices and integrated circuits of the target with a form of signal with a certain frequency and a special waveform. By this means, the response-type injury of basic elements of the target, i. e., semiconductor devices and integrated circuits can be brought out and consequently the target is damaged permanently.Study on injury mechanism of a typical microwave LNAs of a special target is carried out in this paper. The effective signal forms for injury microwave LNA are first studied based on both theoretical and experimental analysis. Then injection injury experimental platform is designed and constructed. Aiming at four types of microwave LNA, five categories of injection injury experiments are given. On the basis of it, the injury effects, functional injury and injury mechanism are investigated in detail. Finally, the commercial software is used to simulate characteristics of the microwave LNA. The main contributions are outlined as follows.(1) The principles and structural characteristics of target are investigated in detail, and the first class amplifier in the receiver channel is thought of as the typical device and weak link, so that the experimental samples are focused on microwave LNA. The technical scheme of combining the special target with devices not only can meet the practical requirements, but also reduces the sorts of experimental samples.(2) Injury experimental platform is designed and constructed and experimental fixtures are also prepared. Several categories of injection experiments procedures include continuous wave injection, single pulse injection, series pulse injection and counting the number of pulses injection. Moreover, other special experiments are also worked out. Reports similar to our experimental platform and procedures have not been found yet at home and abroad.(3) The signals in common use are analyzed with respect to signal energy, power and power spectra. With the property of bipolar transistors taken into account, the injury capabilities of various signal forms are studied. The series pulse form with certain repeating frequency and fixed altitude and duty ratio is proposed and its injury capability is superior to other signal forms.(4) Microwave LNAs ERA-5, ERA-3, A-and E5B made by Mini-Circuits are dissected, and then the circuit diagrams of these LNAs are obtained and analyzed. Five categories of injection experiments on these LNAs are intensively performed and investigated. Injury modes and mechanisms of typical samples are studied with the aid of dissection technique. Experimental results show that the injurious energy is much reduced when special series pulse is used as injection signal, and at the same time the microwave LNAs are damaged permanently. The energy needed to damage microwave LNA can be obtained by means of counting the number of injection pulses. Reports similar to these experimental results have not been found yet at home and abroad, and these valuable experimental results and data can be widely used in the future research.(5) It is first proposed that both power and frequency can act on devices and integrate circuits commonly instead of only power acting, which can make the injury signal power reduced greatly. The experimental results are analyzed and discussed. Experimental results indicate that displacement current makes a great contribution to the injury of devices under the condition of high frequency and large injection. It has been proved that power and frequency can act on devices commonly and result in their injury, which is consistent with theoretical analysis. Experimental results illustrate that the energy needed to make LNA produce injury effects is much lower than that needed to produce functional injury. It can be seen that these results provide the experimental data for lower energy system for the first time. The product of noise and gain of microwave LNA can be used to classify functional injury or injury effects.(6) At present, it is very difficult to build up the injury models of integrate circuits and the physical parameters inside ICs are also difficult to be obtained. As a result, the simulation results of voltage, current and work status of transistors inside the LNA are obtained with the aid of the commercial software. Semi-quantitative and qualitative simulation results are consistent with experimental results. These research works make a contribution to the injury experiment results prediction and quantitative simulation of LNA.Silicon Carbide (SiC) has outstanding properties such as high saturated electron drift velocity, high electric breakdown field and high thermal conductivity, so that it is a very promising wide band gap semiconductor material which can be applied in high-temperature, high power, high frequency, anti-radiation, ultraviolet detector and high-temperature pressure sensors. At the present, the key processes such as preparing SiC films, dry etching and patterns transferring have been studied with considerable attention and intensively investigated. In this work, the emphasis is laid on the technology of hetero-epitaxial SiC films on Si substrates and plasma etching SiC films. The main contributions are outlined as follows. Firstly, the properties of SiC material, and the technologies of preparing SiC material and SiC dry etching are summarily introduced.Secondly, the technique of hetero-epitaxial SiC thin films by atmospheric pressure chemical vapor deposition (APCVD) on Si substrates is systematically studied based on the mature Si epitaxy growth technology. The main works deal with hetero-epitaxial growth process scheme, carbonized buffer layer technique, effects of the epitaxial temperature on SiC films microstructure, chemical composition of epitaxial SiC films and so on. The micro mechanism of hetero-epitaxial SiC on Si substrates is discussed and the optimum epitaxial growth process conditions are obtained.Thirdly, CF4+O2, SF6+O2 and SF6+N2 plasma etching of SiC films made by hetero-epitaxial growth on Si substrates has also been systematically performed in this work. Effects of different etching gases on plasma etching of SiC material are compared and discussed and the optimum plasma etching process conditions are obtained. Plasma pattern etching of SiC single crystalline thin films is studied on the basis of plasma etching technology. The patterns meeting the precision requirements of SiC high-temperature well pressure sensors have been successfully finished.In this paper, study on hetero-epitaxial growth SiC thin films and plasma etching process is carried out systematically. Papers in this field are few at home. Research on SiC growth and dry etching is still in the beginning process.