Breakdown point transfer theory for Si/SiC heterojunction LDMOS with deep drain region

Abstract

Abstract Heterojunction terminal technology, especially Si/SiC heterojunction, has been widely used in the power semiconductor device. Si/SiC heterojunction LDMOS combines the advantages of Si and SiC while the breakdown point is transferred due to employing the deep drain region structure to improve the BV of the device. Based on the existing research, a new theory about breakdown point transfer terminal technology is proposed for silicon on silicon carbide lateral double-diffused metal oxide semiconductor field effect transistor with deep drain region based on the electric field modulation in this paper for the first time. A concise and efficient analytical theory is presented to predict the breakdown voltage and electric field (E-field) distributions of Si/SiC LDMOS. The mechanism of surface electric field modulated and optimized by breakdown point transfer terminal technology is explained. Introducing the drain region impact factor into the analytical model to decouple the lateral and vertical depletion below the drift region. The analytical model proves that the deep drain region structure can modulate both the lateral and vertical electric field. Meanwhile, the location of the breakdown point can be determined by the E-field distribution at y = TDr and the E-field distribution at y = TSi, which is demonstrated by both theoretical interpreting and simulation. The derivations were verified using the ISE TCAD with a good agreement in the analytical model by changing the key structural parameters of the device. This analytical theory can be applied to other heterojunction power devices.