Investigation of line tunnel field effect transistor with Ge/Si heterojunction

Two-dimensional numerical simulation of a line tunnel field effect transistor with Ge/Si heterojunction was conducted. It was shown that this proposed device has a considerably high on-state current (I_on) at an ultra low drain voltage thus a high I_on/I_off ratio. The shortening of the gap-channel region can produce a higher Ion. But the I_off of this transistor was increased more enormously with the obvious deterioration of subthreshold swing. On this basis, a heteromaterial gate structure which can modulate the barrier height at the gap-channel region was introduced to obtain a higher Ion and lower I_off simultaneously even with a very short gap-channel region.