Research On 1200V Field Stop IGBT

Insulated Gate Bipolar Transistor(IGBT)is a representative product of the third technological revolution of power semiconductor devices.It has various excellent performances such as high frequency,high voltage,large current,easy switching,etc.Field-Stop Insulated Gate Bipolar Transistor(FS IGBT)is the mainstream IGBT structure in the world after the development of several generations of different IGBT chip structures.Its products have been widely used in consumer electronics and industrial control,Electric vehicles,smart grids and other fields,China has now developed into the world’s largest market for IGBT demand.This paper proposes a design and manufacturing method for a 1200 V planar gate FS-IGBT device,and completes the IGBT chip tape out and test work through the 6-inch 0.35μm process of Tianjin Zhonghuan Semiconductor Co.,Ltd.The main research contents of this article are as follows:1.In terms of chip structural design,it is mainly divided into two parts: cell and terminal design.The device structure is verified through simulation to verify electrical characteristics parameters,and important single-process experimental verification is carried out in conjunction with the production line,and the international mainstream field cut-off Technology,an improved back-side thinning process is proposed to reduce the thickness of the chip to 120μm,which is reduced by more than 30% compared to the non-punch through insulated gate bipolar transistor(NPT-IGBT)of the same specification,and Improve the heat dissipation capacity of the device during operation.2.In the cell structure design,a carrier storage technology is introduced.By introducing an N-type carrier storage layer(CS)at the bottom of the P-type base region,the forward voltage drop of the device is reduced It is about 0.6V,which improves the reverse bias safe working area and improves the reliability of the device.3.In the terminal process,a passivation structure is designed to improve the voltage resistance of the terminal.By using a polyimide photoresist(Polyimide,PI)passivation process instead of the traditional silicon nitride(Nitride)passivation layer The passivation process is completed by photolithography and curing,eliminating the original passivation medium deposition,etching,degumming and cleaning processes,greatly shortening the process flow,shortening the process time of this layer by about 8 hours,and reducing the layer flow 20% of the film cost..The test results show that the chip withstand voltage is above 1200 V,the threshold voltage is 6.59 V,the reverse leakage current is 0.8m A,and the collector-emitter saturation voltage drop is 1.44 V.