A Study of compressively strained Si0.5Ge0.5 metal-oxide-semiconductor capacitors with chemical vapor deposition HfAlO as gate dielectric

作者：Huang Jidong; Fu Jia; Zhu Chunxiang^*; Tay Andrew A O; Cheng Zhi Yuan; Leitz Chris W; Lochtefeld Anthony

来源：Applied Physics Letters, 2007, 90(2): 023502.

DOI：10.1063/1.2431464

The interfacial and electrical properties of metal organic chemical vapor deposited HfAlO on compressively strained Si0.5Ge0.5 (epsilon-Si0.5Ge0.5) substrate without or with surface nitridation treatment were investigated. X-ray photoelectron spectroscopic analysis suggests that an interfacial layer containing GeOx, Hf silicate, and Al silicate exists on substrates with direct deposition of HfAlO, whereas an interfacial layer containing SiNxOy exists on substrates with surface nitridation prior to HfAlO deposition. The TaN/HfAlO/epsilon-Si0.5Ge0.5 capacitor with surface nitridation shows a larger permittivity of the entire gate dielectric with a thinner interfacial layer (in terms of equivalent oxide thickness) a smaller interface trap charge density, and less severe flatband shift as well as two orders of magnitude lower gate leakage in comparison with those capacitors without nitridation.

• 出版日期2007-1-8