Patent ID: 6982468
Filing Date: 2006-01-03
Classification: H01L

Abstract:
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.