Hydrogen-radical-balanced steam oxidation for growing ultra-thin high-reliability gate oxide films

A unique oxidation technology has been developed, in which oxidation proceeds in competition with reduction by active hydrogen. Active hydrogen in the oxidizing ambient immediately attacks weak spots formed in the oxide in the midst of oxidation processes, allowing only high-integrity oxide to survive and grow. In order to preserve a contamination-free Si-SiO/sub 2/ interface up to the start of oxidation, ultra clean chemical oxide is utilized as a passivation film. As a result, gate oxide films as thin as 5 nm featuring high breakdown fields and excellent endurance against charge injection have been obtained. The purpose of this paper is to report on the state-of-the-art ultra clean thermal oxidation technology.<>