Abstract: A surface of a semiconductor wafer has a first gate oxide area and a second gate oxide area. A first gate oxide layer and a photoresist layer are formed on the surface of the semiconductor wafer. A wet etching process is performed to remove the first gate oxide layer not in the first gate oxide area on the surface of the semiconductor wafer. The photoresist layer is then removed. After performing a wet cleaning process, a second gate oxide layer is formed on the surface of the semiconductor wafer. Finally, a two-step polysilicon deposition process is performed, the resultant polysilicon layer covering the first gate oxide area and the second gate oxide layer. The two-step polysilicon deposition process involves a first-step low temperature amorphous silicon (&agr;-Si) deposition process, and a second-step high temperature polysilicon deposition process so as to avoid the formation of particles and defects when forming the polysilicon layer.

Abstract: A method for fabricating gate oxide includes a dilute wet oxidation process with additional nitrogen and moisture and an annealing process with a nitrogen base gas, wherein the volume of additional nitrogen is about 6-12 times of the volume of the additional moisture. The method according to the invention improves the electrical quality of the gate oxide by raising the Q.sub.bd and by reducing the leakage current of the gate oxide.

Abstract: A horizontal oxidation furnace injector comprising an inner tube and an outer tube. The inner tube has an inner tube inlet and an inner tube outlet. The inner tube inlet is used for receiving a first gas and the inner tube outlet is used for outputting the first gas. The outer tube has a branch tube and an outer tube outlet. The branch tube further includes an outer tube inlet. The outer tube inlet is used for receiving a second gas, and the outer tube outlet is used for outputting the secord gas. Furthermore, the outer tube outlet and the inner tube outlet are at the same end. In addition, part of the inner tube is enclosed by the outer tube of the injector while the remainder of the inner tube is exposed, and the inner tube has no bends.

Abstract: A method for fabricating gate oxide includes a dilute wet oxidation process with additional nitrogen and moisture and an annealing process with a nitrogen base gas, wherein the volume of additional nitrogen is about 6-12 6-20 times of the volume of the additional moisture. The method according to the invention improves the electrical quality of the gate oxide by raising the Qbd and by reducing the leakage current of the gate oxide.