Source/drain junction fabrication for Ge metal-oxide-semiconductor field-effect transistors

作者：Yamamoto Keisuke; Yamanaka Takeshi; Ueno Ryuji; Hirayama Kana; Yang Haigui; Wang Dong; Nakashima Hiroshi^*

来源：Thin Solid Films, 2012, 520(8): 3382-3386.

DOI：10.1016/j.tsf.2011.10.047

• Ge channel
• MOSFET
• pn junction
• Surface passivation

We established fabrication methods for high-quality Ge n(+)/p and p(+)/n junctions using thermal diffusion of P and implantation of B, respectively. The carrier concentrations in n(+) and p(+) layers were as high as 4 x 10(19) and 2 x 10(19) cm(-3), respectively. It was found that a peripheral surface-state current dominates the reverse leakage current in an n(+)/p junction diode. The protection of junction surfaces from plasma damage during the SiO2 deposition was essential to achieve high-quality source/drain junctions. The surface passivation with a GeO2 interlayer was harmful to an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) because of an increase in a surface leakage current due to inversion carriers. For a p-channel MOSFET, on the other hand, the GeO2 interlayer plays a role in decreasing the surface leakage current.

• 出版日期2012-2-1