High-k gate stack on germanium substrate with fluorine incorporation

作者：Xie Ruilong^*; Yu Mingbin; Lai Mei Ying; Chan Lap; Zhu Chunxiang

来源：Applied Physics Letters, 2008, 92(16): 163505.

DOI：10.1063/1.2913048

In this letter, a postgate CF(4)-plasma treatment is proposed and demonstrated on germanium (Ge) metal-oxide-semiconductor capacitors and the effects of fluorine (F) incorporation have been studied on both high-k/Ge gate stacks without any surface passivation and with Si surface passivation. Our results show that F is effectively introduced into the gate stack by CF(4) treatment and segregates near high-k/Ge interface. Electrical characteristics such as frequency dispersion, interface state density (D(it)), and gate leakage are improved after F incorporation. Interface quality of high-k/Ge gate stack is further improved by combining Si surface passivation and postgate CF(4) treatment, with its D(it) as low as 4.85x10(11) cm(-2) eV(-1).

• 出版日期2008-4-21