US 6,982,468 B2
Semiconductor device and method for manufacturing thereof
Shimpei Tsujikawa, Tokyo (Japan); Toshiyuki Mine, Fussa (Japan); Jiro Yugami, Yokohama (Japan); Natsuki Yokoyama, Mitaka (Japan); and Tsuyoshi Yamauchi, Akishima (Japan)
Assigned to Renesas Technology Corp., Tokyo (Japan); and Hitachi ULSI Systems Co., Ltd., Tokyo (Japan)
Filed on Sep. 16, 2004, as Appl. No. 10/942,014.
Application 10/942014 is a continuation of application No. 10/452126, filed on Jun. 03, 2003, granted, now 6,897,104.
Claims priority of application No. 2002-166630 (JP), filed on Jun. 07, 2002.
Prior Publication US 2005/0029600 A1, Feb. 10, 2005
Int. Cl. H01L 29/76 (2006.01)
U.S. Cl. 257—411 1 Claim
OG exemplary drawing
 
1. A semiconductor device comprising:
a first semiconductor domain and a second semiconductor domain isolated from each other by a field dielectric layer for device isolation formed selectively on a surface of a silicon semiconductor substrate;
a first MOS (Metal Oxide Semiconductor) device having a nitrogen-containing silicon oxide film formed on a surface of the first semiconductor domain as a gate dielectric; and
a second MOS device having an oxygen-containing silicon nitride film formed on a surface of the second semiconductor domain as a gate dielectric, the oxygen-containing silicon nitride film being formed from a silicon nitride film having a thickness of 1.5 nm or less and into which oxygen is introduced to provide an equivalent oxide thickness of 2.5 nm or less,
wherein the nitrogen concentration in the nitrogen-containing silicon oxide film is maximum either at a surface of the silicon oxide film or at a boundary between the silicon oxide film and the silicon semiconductor substrate, and the oxygen concentration of the oxygen-containing silicon nitride film is minimum in a portion of the oxygen-containing silicon nitride film intermediate a surface of the oxygen-containing silicon nitride film and boundary between the oxygen-containing silicon nitride film and the silicon semiconductor substrate.