The source-heterojunction-MOS-transistor provides high drain current. This is originated from the high velocity electron injection at the source edge due to band offset energy. However, these devices suffer from large off-state current. In this paper, we have analyzed the off-state current in this device and have proposed use of work function engineering as well as asymmetric gate oxide to minimize the magnitude of this off-state current. The analysis of the off-state current characteristics shows that provided 93% reduction in off-state current.