A SiC LDMOS with electric field modulation by a step compound drift region

作者：Bao, Meng-tian; Wang, Ying^*; Yu, Cheng-hao; Cao, Fei

来源：Superlattices and Microstructures, 2018, 119: 94-102.

DOI：10.1016/j.spmi.2018.04.046

• SiC LDMOS
• Breakdown voltage
• Specific on-resistance
• Switching characteristic
• Self-heating
• Compound drift region

In this paper, we propose a SiC LDMOS structure with a step compound drift region (SC-LDMOS). The proposed device has a compound drift region which consists of an n-type top layer, a step p-type middle layer and an n-type bottom layer. The step p-type middle layer can introduce two new electric field peaks and uniform the distribution of the electric field in the n-type top layer, which can modulate the surface electric field and improve the breakdown voltage of the proposed structure. In addition, the n-type bottom layer is applied under the heavy doping p-type middle layer, which contributes to realize the charge balance. Furthermore, it can also increase the doping concentration of the n-type top layer, which can decrease the on resistance of the proposed device. As a simulated result, the proposed device obtain a high BV of 976 V and a low R-sp,R-on of 7.74 m Omega.cm(2). Compared with the conventional single REUSRF LDMOS and triple RESURF LDMOS, BV of proposed device is enhanced by 42.5% and 14.7%, respectively and R-sp,R-on is reduced by 37.3% and 30.9%, respectively. Meanwhile, the switching delays of the proposed device are significantly shorter than the conventional triple RESURF LDMOS.

• 出版日期2018-7
• 单位杭州电子科技大学; 哈尔滨工程大学