Title :
Advanced oxynitride gate dielectrics for CMOS applications
Author :
Yugami, Jiro ; Tsujikawa, Shimpei ; Tsuchiya, Ryuta ; Saito, Sinichi ; Shimamoto, Yasuhiro ; Torii, Kazuyoshi ; Mine, Toshiyuki ; Onai, Takahiro
Author_Institution :
Wafer Process Eng. Dev. Div., Renesas Technol. Corp., Hyogo, Japan
Abstract :
A most preferable candidate of gate dielectrics in advanced CMOS to satisfy the requirement of an ITRS roadmap is still SiON, especially for high-performance and low-power devices. To advance the efficiency of SiON gate dielectrics, the keyword is N-rich. A high nitrogen concentration leads to low leakage current and high immunity to impurity penetration. However, in N-rich SiON, the mobility degradation and NBTI enhancement due to fixed charges formed by incorporated nitrogen atoms near the interface are problems. To solve these problems, we developed a SiN gate dielectric with an oxygen-enriched interface (OI-SiN). A process in which oxygen atoms are incorporated after forming SiN provides enhanced nitrogen concentration and an oxygen-enriched interface while simultaneously suppressing fixed charges, even in dielectrics having sub-nm EOT. This OI-SiN has good immunity against impurity penetration and provides superior device performance compared to the conventional SiON. Furthermore, the OI-SiN was much effective as an interfacial layer of high-K gate stack to solve problems in high-K gate dielectric.
Keywords :
CMOS integrated circuits; MOSFET; dielectric devices; dielectric materials; electron mobility; elemental semiconductors; leakage currents; permittivity; silicon; silicon compounds; SiON-Si; impurity penetration; interfacial layer; leakage current; mobility degradation; nitrogen concentration; oxygen enriched interface; oxynitride gate dielectrics; Degradation; Dielectric devices; High K dielectric materials; High-K gate dielectrics; Impurities; Leakage current; Niobium compounds; Nitrogen; Silicon compounds; Titanium compounds;
Conference_Titel :
Gate Insulator, 2003. IWGI 2003. Extended Abstracts of International Workshop on
Conference_Location :
Toyko, Japan
Print_ISBN :
4-89114-037-2
DOI :
10.1109/IWGI.2003.159201