Isolation Of The Soi High Voltage Integrated Circuit Technology Research

With its high reliability, small area, high-speed performance and low power dissipation, the High Voltage Integrated Circuit (HVIC) has unchangeable effect in the area of military affairs, aviation and nuclear energy. Now, HVIC has been utilized in communication, auto-electronics and other fields. As the development of SOI (Silicon on Insulator) preparation technology and the decrease of SOI material's cost, it provides a wider space for the exploitation of high-performance HVIC based on the flexibility material structure and the complete dielectric isolation technology.According to the thickness of the SOI film, high voltage IC based on SOI material (SOI-HVIC) can be divided into thin-film and thick-film.For thin-film SOI-HVIC, linear drift region doping profile is adopted to satisfy a certain breakdown-voltage, but this process is too complex and its self-heating effect is obvious; for thick-film SOI-HVIC, it can take advantage of CMOS technology on Silicon to obtain the high voltage. The key point of thick-film SOI-HVIC is the dielectric isolation due to its thick silicon layer.In this paper, the research of the dielectric isolation of over-20μm-film SOI is concentrated on the structure, technology and experiment. Firstly, the deep trench dielectric isolation structure is designed, and a mathematical model of the breakdown-voltage is given. Then the ideal models (dielectric isolation structure with High-Voltage Interconnection and without High-Voltage Interconnection) are simulated by a 2D device simulator MEDICI respectively. According to the simulation results, the two models'breakdown mechanism is analyzed and compared, and the influence of the isolated trench structure parameter on breakdown-voltage is studied, synchronously.Secondly, a novel technology is proposed which includes several key steps such as LPCVD (Low Pressure Chemical Vapor Deposition) nitride silicon and CMP (Chemical Mechanical Polishing). The technology is simulated and optimized by process simulation software TSUPREM-4, and an effective model is created in this step. Then the effective model (with High-Voltage Interconnection) is simulated by MDEICI. The results of simulation are compared to the results of the ideal model. In addition, the...