Implementation of a short channel (0.3 μm) for 4H-SiC MOSFETs with deep P-well using ‘channeling’ implantation

This paper proposes 1.2 kV 4H-SiC MOSFETs with deep P-well structure using channeling implantation to enable short channel length. In order to form deep junctions using low energy implantation, channeling implantation was utilized. The proposed MOSFETs with short channel (0.3 μm) achieved high breakdown voltage with low leakage current, whereas the conventional MOSFETs of similar rating provide very large leakage current. A deep P-well structure helps suppress the leakage current from the channel under the forward blocking mode. Consequently, specific on-resistance was reduced by approximately 10 % using the proposed MOSFETs with channel length of 0.3 μm. Moreover, the conventional trade-off relationship between specific on-resistance and short-circuit withstand time was improved in the proposed MOSFETs with short channel length due to the deep P-well structure. Output, blocking, and short-circuit characteristics measured from fabricated 1.2 kV SiC MOSFETs were performed. In addition, Sentaurus 2D TCAD was used to support and clarify the experimental results.