Patent ID: 8043981

Claim:
A method of forming an oxide layer on a stack on a semiconductor substrate by low temperature plasma oxidation, comprising: placing the semiconductor substrate on a substrate support in a chamber of a plasma reactor; introducing a gas into the chamber, the gas consisting essentially of oxygen and an optional second gas selected from hydrogen, helium, argon, krypton, neon and xenon; supplying power to a power source operating at a first frequency to generate a first plasma containing ionized oxygen within the chamber; supplying power to a power source operating at a second frequency, wherein the second frequency is higher than the first frequency; and growing the oxide layer at a temperature below 700° C. on the stack on the semiconductor substrate by oxidizing the stack including a pair of sidewalls and the power supplied at the first frequency and the second frequency is selected to provide sufficient energy to cover the sidewalls and to prevent damage to the semiconductor substrate, wherein the oxide layer is formed in a first step in which no power is supplied at the first frequency while power is supplied at the second frequency and in a second step in which power is supplied at the first frequency and the second frequency.