DEPOSITION OF OXIDE IN SEMICONDUCTOR DEVICE

• Main Authors: NAKANISHI TOSHIRO, SATO YASUHISA
• Format: Patent
• Language: English
• Published: 10.03.1995
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To deposit a thin oxide uniformly with no surface roughness by depositing a first oxide on the surface of a semiconductor layer and then depositing a second oxide through thermal oxidation in an oxidation furnace under reduced pressure thereby retarding evaporation of atoms of semiconductor from the surface thereof. CONSTITUTION:At first, the pressure in an oxidation furnace 1 is reduced to 1X10<-6>Torr and the atmosphere at the upper part in the furnace is heated to 1000 deg.C by means of a heater 2. A silicon wafer 10 is then mounted on a wafer carrier 3 which is then elevated to a uniform temperature band surrounded by the heater 2. In the way of elevation, oxygen gas is fed through a gas introduction pipe 8 of the oxidation furnace 1 and the inner pressure is increased up to 1Torr. Consequently, a preliminary oxide 11 is deposited by 1-2nm on the surface of the silicon wafer 10. At a moment when the silicon wafer 10 arrives at the upper uniform temperature band, oxygen gas supply is increased to promote oxidation on the surface of the silicon wafer 10 thus depositing an oxide 12.