A study of dopant effects in MOSFET with dopant segregated schottky-barrier

Abstract

Dopant segregated Schottky-barrier MOSFET (DSSB-MOSFET) is promising device to replace the conventional MOSFET. We have to understand the dopant effect to improve DSSB-MOSFET characteristics because dopant affects the device characteristic significantly. Therefore dopant effects are investigated based on effective SBH concept using DSSB-MOSFET fabricated on bulk-substrate by varying dopant dose and energy condition. By conducting experiment using arsenic ion, we confirm that energy band of silicon is changed due to dopants; thereby device characteristic is significantly changed. As well, it is verified that one of the most significant problems named off-current can be suppressed by energy band engineering. Experi-mental result with sulfur ion implantation shows anomalous behavior which is different from previously re-ported result. To interpret this anomalous behavior, diode characteristics are also investigated, and then we suggest possible mechanisms for this phenomenon. To acquire better device performance, arsenic ion and sulfur ion are co-implanted at the same time. It is verified that DSSB-MOSFET can be used for different ap-plication by optimization of dopant ion implantation condition.