Novel Si/SiC heterojunction lateral double-diffused metal oxide semiconductor field effect transistor with low specific on-resistance by super junction layer

摘要

A novel Si/SiC heterojunction lateral double-diffused metal oxide semiconductor (LDMOS) field effect transistor with the low specific on-resistance (R_(on,sp)) by super-junction (SJ) layer (Si/SiC SJ-LDMOS) is proposed in this paper. On the basis of using N-Buffer layer to solve substrate assisted depletion effect (SAD), breakdown point transfer terminal technology (BPT) is realized by the deep drain structure of Si/SiC heterojunction and electric field modulation is carried out, which further improves the breakdown voltage (BV) of Si/SiC SJ-LDMOS, alleviates the contradictory relationship between the BV and the R_(on,sp). Through ISE TCAD simulation, the result shows that with the same drift region length of 20 μm, the BV is increased from 114 V of conventional SJ-LDMOS (Cov. SJ-LDMOS) and 270 V of SJ-LDMOS with N-Buffer layer (Buffer SJ-LDMOS) to 374 V of Si/SiC SJ-LDMOS, increased by 228% and 38%, respectively. In addition, the R_(on,sp) of Cov. SJ-LDMOS, Buffer SJ-LDMOS and Si/SiC SJ-LDMOS are 46.26 mΩ cm~2, 26.96 mΩ cm~2 and 25.85 mΩ cm~2, respectively. Moreover, the figure-of-merit (FOM) of proposed Si/SiC SJ-LDMOS device is 5.411 MW/cm~2, which means the Si/SiC SJ-LDMOS has a better performance to break the silicon limit. The influence of design parameters on device performance is also discussed.