Formation of Thin Oxides

Following methods are used to grow thin oxide films:

• Reduced pressure oxidation offers an attractive way of growing thin oxides in a controlled way. Oxides between 30 and 140°A thick have been grown at 900 to 1000°C using oxygen at a pressure of 0.25 to 2.0 torr. The reduced pressure oxides are very uniform, homogeneous, and similar to thicker oxides prepared at atmospheric pressure. [3]

• Another method is a two-step sequence. First a uniform, reproducible oxide of small defect density is formed at 1000°C or less using dry O₂-HCl ambient. Then the second step consists of a heat treatment in N₂, O₂ and HCl at 1150°C to provide passivation and to bring oxide thickness to the desired level. [3]

• Another method uses high-pressure, low-temperature steam-oxidation of silicon. At 10-atmosphere pressure and 750°C, a 300°A thick oxide can be grown in 30 minutes. [3]