Pecvd Silicon Nitride Film Preparation Process, And Simulation Studies

Power semiconductor device chip manufacturing process is actually repeated several times on film formation, lithography and doping process in a substrate, and its primary task is to solve the problem of film formation. With the continuous development of power semiconductor devices required ever-increasing varieties of the films, the film's performance requirements is increasing also, the new preparation method followed emerging and maturing. In power semiconductor devices, for example, the early devices grown thermal oxidation of silicon and single metal films on silicon substrate; with the progress and development of semiconductor process technology, in order to improve device stability and reliability, it needed deposition PSG, Si3N4, semi-insulating polycrystalline silicon and so passive film. Silicon nitride is an excellent functional material; it has good dielectric properties (low dielectric constant, low loss), high insulation, and the high density of silicon nitride have good blocking ability off impurity ions, even in small sizes Na+. Therefore, the silicon nitride used as an efficient device surface passivation layer and is widely used in semiconductor processes.Preparations of thin films are mainly two categories, namely physical deposition and chemical deposition. Vacuum evaporation, cathode sputtering, molecular beam epitaxy, is physical deposition. Growth by chemical reaction method called chemical deposition method; it points to the chemical liquid deposition and chemical vapor deposition types. At present, the chemical vapor deposition method to grow silicon nitride thin films are mainly plasma enhanced chemical vapor deposition method (PECVD), low pressure chemical vapor deposition method (LPCVD), radio frequency plasma enhanced chemical vapor deposition method (RF-PECVD), photochemical vapor deposition method (optical CVD) and so on.Plasma enhanced chemical vapor deposition (PECVD) is an ideal and important preparation methods of silicon nitride film. Preparation of silicon nitride with PECVD is complexity, there are many control factors in deposition process, and deposition conditions have a direct impact on structure and properties of dielectric films. Therefore, there are a number of parameters must be controlled in PECVD deposition process, and the deposition conditions optimization is very important. Influence of silicon nitride thin film deposition process parameters included temperature, RF power, RF frequency, chamber pressure, gas (SiH4/NH3) flow ratio.The study background ,application and develop trend of CVD, and the study presrnt condition of CVD technique were intruduced in this paper. The constitute of PECVD system and related work principle were intruduced also. The work project and application of PECVD craft technique were given in this paper.In the paper, the part of software showed stress simulation research and result of silicon nitride thin films with Silvaco TCAD in PECVD.