Investigation of Cu Õ TaN Metal Gate for Metal-Oxide-Silicon Devices

Content Provider	Semantic Scholar
Author	Tsuiz, Bing-Yue Huang, Chih-Feng
Copyright Year	2002
Abstract	This work investigates the work function modulation of TaN x films and the thermal stability of Cu/TaN x stack as a gate electrode for metal-oxide-silicon devices. The N/Ta ratio was varied in the range of 0.30-0.65 by using reactive-sputter deposition with various Ar/N2 mass flow ratios. The TaN x films are almost amorphous and are thermally stable up to 800°C. However, the formation of Ta3N5 phase in a film with a high N/Ta ratio or annealed at high temperature increases the resistivity. The work function of TaNx is about 4.31-4.38 eV and the modulation is less than 70 mV. Such a short range modulation of the work function implies that TaNx is only suitable to be a gate electrode of surface channel n-channel metal oxide semiconductor field effect transistors~NMOSFETs!. The mean value of the flatband voltage decreases and the deviation of the flatland voltage increases with the increase of the annealing temperature. Although phase change, grain growth, and Cu contamination contribute to the instability at high temperature, thermal stress-induced oxide charges dominate this decrease and deviation of the flatband voltage at temperature below 500°C. According to the material and electrical analysis, the Cu/TaN x st ck gate electrode can be used for NMOSFETs only, and the maximum process temperature following gate electrode deposition should be lower than 500°C. © 2002 The Electrochemical Society. @DOI: 10.1149/1.1522723 # All rights reserved.
File Format	PDF HTM / HTML
Alternate Webpage(s)	https://ir.nctu.edu.tw/bitstream/11536/28243/1/000180069000053.pdf
Language	English
Access Restriction	Open
Subject Keyword	Chemical vapor deposition Copper Fever Field effect (semiconductor) Instability Metal gate Modulation Semiconductor Silicon Simulated annealing Skin tanning Sputter deposition Transistor metal oxide newton phase change sequestering of metal ion voltage
Content Type	Text
Resource Type	Article