Research On Gate Polysilicon Gap Defects Of Trench MOSFET And Process Optimization

In recent years, many electronic devices toward smaller and smaller while theefficiency is increased accordingly direction. Trench MOSFET (Metal OxideSemiconductor Field Effect Transistor) technology is developed in such a context. Isa new vertical trench MOSFET device structure, as it has fast switching speed, goodtemperature characteristics, good frequency performance, high input impedance,drive power is small, no secondary breakdown problems and so on merit, has beenwidely used in the power management modules, voltage regulators, electrical control,display control, automotive electronics and other fields. Most importantly, since thechannel of trench MOSFET is vertical, the channel density can be further increased toreduce the size of semiconductor devices. While reducing the size of semiconductordevices are also actively responded to Moore’s Law, is an integrated circuit currentand future direction of development. Trench gate structure is a process with a trenchMOSFET device fabrication is the most unique core technology, process defects ofany gate would most likely lead to changes in electrical parameters of semiconductordevices, device reliability, timeliness and even lower. Therefore, optimized gateprocess is extremely important for the trench MOSFET device performance,reliability, and improve product yield.This paper first introduces the application and development of MOSFETtechnology, and then by comparing the structure VDMOSFET (VerticalDouble-diffused MOSFET) and trench MOSFET, to introduce the trench MOSFETgate-related production process, including the dry etching process, heat oxidationprocess and chemical vapor deposition processes, etc., and in accordance with theprinciples of the gate each process analyzes the causes of the MOSFET gatepolysilicon trench gap defects and, finally, the production process according to thetheory and practice of effective solutions and experimental results of the gap defectsprocess optimization method. The process optimization method includes optimizingcross-sectional structure of a trench gate oxide chemical vapor deposition processoptimization and process optimization of polysilicon and other aspects. Using thisprocess optimization method can completely solve the trench MOSFET gatepolysilicon gap defects, thereby improving the electrical parameters ofsemiconductor-related devices, improving product yields, reduced scrap problem.