Improving breakdown voltage of SiC/Si heterojunction with graded structure by rapid thermal CVD technology

A novel graded process has been developed to improve the characteristics of SiC/Si heterojunction diode (HJD) by rapid thermal chemical vapor deposition (RTCVD). The graded process was obtained by varying the flow of C3H8 gas from 0-10 seem with a ramp rate of 2 sccm/min. The developed SiC/Si heterojunction diodes exhibit good rectifying properties, At forward bias, the built-in voltage of 0.63 V and excellent ideality factor n 1.28 were obtained by C-V and I-V measurements, respectively, For reverse bias, the breakdown voltage more than 16 V with low leakage current density Is 3.74 x 10(-4) A/cm(2) at 16.2 V reverse bias, Additionally, the SEM and TEM cross section have been employed to evidence that the graded method has a better SiC/Si interface than the conventional carbonization process.