Relybility Study Of The Interface Region In The Gate-controlled Power Semiconductor Devices

At present, the gate-controlled power semiconductor devices are widely used in induction heating, traction drives, smart grid and other fields of power electronics.MOSFET and IGBT, the representative ones, represent the trends of becoming higher voltage and higher frequency for power semiconductor devices. However, as the development of becoming higher frequency and larger power, there is a need to propose more stringent targets and requirements for the gate-controlled power semiconductor devices. Many failure modes are manifested in the applications, in which the interface region of the devices has an over-current turnoff failure under the inductive load. So this paper will give a more deeper study about this failure on the basis of simulations and relevant study. And the purpose of this paper is to trigger the interest of relevant domestic enterprises and research institutions in the reliable research of power devices.The work of this paper include the following parts:1. Simulations will be carried out to determine the over-current turnoff failure in the interface region of the devices under inductive load. Then detailed analysis about the changes of the voltage, the current and the temperature located in the interface region under the turnoff process will be performed.2. Next, this paper will reveal the physical failure mechanisms of the interface region under over-current turnoff process. And will analyze the temperature rise and dynamic avalanche phenomenons caused by the current crowding in the interface region.3. On the basis of above analysis, a heat flow model will be proposed about the temperature rise in the interface region. And the current can be regarded as constant in temperature rising process, so the heat flow model could be solved easier.4. A terminal structure will be proposed according to the RC-IGBT manufacture process, and simulations about this structure prove it can significantly alleviate the temperature rise in the interface region. This will provide theoretical and technical support for the failure large-scale manufacture.