Structural and electrical properties of thin SiO 2 layers grown by RTP in a mixture of N 2O and O 2

Abstract

Ultrathin (< 10 nm) dielectric films for application in metal-oxide-semiconductor devices have been fabricated in an O 2:N 2O atmosphere using rapid thermal processing. It is shown that with increasing N 2O content in the mixtures of N 2O and O 2, the oxide thickness decreases and the interfacial nitrogen concentration increases. Therefore, the nitrogen concentration at the Si SiO 2 interface, responsible for improved electrical characteristics, is adjustable by the O 2:N 2O ratio. High charge-to-breakdown ( Q BD) values comparable to oxides processed in pure N 2O atmosphere are obtained for electron injection from the Si substrate. For electron injection from the gate, the Q BD values are considerably higher. For an O 2:N 2O ratio of 3:1 the highest Q BD values have been obtained together with a very homogeneous Q BD distribution across the wafer.