Title :
Low-pressure rapid thermal chemical vapor deposition of oxynitride gate dielectrics for n-channel and p-channel MOSFETs
Author :
Hill, Winford Lee ; Vogel, Eric M. ; Misra, Veena ; McLarty, Peter K. ; Wortman, Jimmie J.
Author_Institution :
Dept. of Electr. & Comput. Eng., North Carolina State Univ., Raleigh, NC, USA
fDate :
1/1/1996 12:00:00 AM
Abstract :
The properties of oxynitride gate dielectrics formed using a low-pressure, rapid thermal chemical vapor deposition (RTCVD) process with SiH4, NH3, and N2O as the reactive gases are presented. Material analyses show an increase of uniform nitrogen and interfacial hydrogen content with increasing NH3/N2O flow rate ratio. MOS capacitors with both n-type and p-type substrates and both n-channel and p-channel MOSFETs were analyzed electrically. The results show increasing fixed oxide charge and interface state density with increasing nitrogen and hydrogen content in the film. A decrease in peak transconductance and improved high-field transconductance was observed for n-channel MOSFETs. Improved resistance to hot-carrier interface state generation was also observed with increasing nitrogen concentration in the films. The results suggest that an optimal nitrogen concentration of approximately 3 at.% can be considered for further development of this technology
Keywords :
MOS capacitors; MOSFET; chemical vapour deposition; dielectric thin films; hot carriers; interface states; rapid thermal processing; silicon compounds; MOS capacitors; MOSFETs; N2O; NH3; SiH4; SiON; fixed oxide charge; high-field transconductance; hot-carrier interface state; interface state density; oxynitride gate dielectrics; peak transconductance; rapid thermal chemical vapor deposition; reactive gases; Chemical vapor deposition; Dielectric materials; Gases; Hydrogen; Interface states; MOS capacitors; MOSFETs; Nitrogen; Rapid thermal processing; Transconductance;
Journal_Title :
Electron Devices, IEEE Transactions on