Abstract: A two step source/drain annealing process which permits a dopant to be ion implanted directly into the silicon without a protective oxide. The gate oxide is removed before the ion implantation of the dopant occurs, thus the dopant is implanted directly into bare silicon. In a first step of the annealing process, a thin oxide is grown over the source and drain regions at a relatively low temperature (e.g., 600.degree. C.) this temperature to prevent the evaporation of the dopant from the silicon substrate and polysilicon gate. The second step of the annealing process occurs at a higher temperature allowing the dopant to be driven into the substrate forming the source and drain regions.

Abstract: An Si.sub.3 N.sub.4 layer is formed on a surface of a wafer, which is an object to be processed, at a high temperature of, for example, 780.degree. C., using a vertical thermal processing apparatus having a reaction tube of a double-wall structure comprising an inner tube and an outer tube in which a predetermined reduced-pressure status is maintained within the reaction tube while a reaction gas comprising, for example, SiH.sub.2 Cl.sub.2 and NH.sub.3 is made to flow from an inner side to an outer side of the inner tube by the action of a first gas supply pipe and first exhaust pipe provided in the thermal processing apparatus. Next, the temperature in the interior of the reaction tube is raised to, for example, 1000.degree. C., a reaction gas comprising, for example, H.sub.2 O vapor and HCl is made to flow from the outer side to the inner side of the inner tube by the action of a second gas supply pipe and second exhaust pipe, and an SiO.sub.2 layer is formed by the oxidation of the surface of the Si.sub.

Abstract: Field oxide regions are formed in a dry oxygen environment containing controlled amounts of HCl at elevated temperatures to reduce edge defects of narrow source/drain regions.