Abstract: A method of fabricating a semiconductor device is provided. The method includes: stacking a gate insulation layer and a polysilicon layer on a semiconductor substrate; forming a photoresist layer on the polysilicon layer; forming a gate stack by etching the gate insulation layer and the polysilicon layer; performing a first impurity ion implantation process to form a shallow first impurity area in the semiconductor substrate; forming a gate spacer layer on one side of the gate stack; and performing a second impurity ion implantation process to form a deep second impurity area in the semiconductor substrate.

Abstract: A photomask according to the present invention for forming a T-gate electrode for Metal Semiconductor Field Effect Transistor and High Electron Mobility Transistor by performing each of the exposing process and the developing process once is disclosed. The photomask is composed of a primary mask positioned at the top surface of the transparent substrate made of Silica glass and a secondary mask positioned at the top surface of the transparent substrate for enhancing the resolution of the primary mask. The primary mask includes an opaque layer in which a material for mask pattern of, for example, Cr or Fe.sub.2 O.sub.3, or other opaque materials is deposited at the bottom surface of the transparent substrate, thereby preventing the light radiated from being transmitted, and a first and second patterns for forming the leg portion and the head portion of the T-gate electrode by simultaneously radiating the light into the exposed portion of the transparent substrate.

Abstract: The present invention relates to a photomask for forming a T-shaped gate structure on a high speed FET through a photolithography, comprising opaque layer patterns 2 and 2a for defining a head portion of the T-shaped gate structure and half-tone layer patterns 3 and 3a for defining a foot portion thereof.The half-tone film patterns composed of a chrome layer are deposited to a thickness thinner than that of the opaque layer patterns so that the half-tone layer patterns show a relatively lower transmittance to an incident beam.The application of the photomask of the invention to the process for forming a T-shaped gate structure improves process reproducibility and leads to great cost savings.