Method of making thin film transistors.

摘要

A method of making thin film transistors such that the first conductive layer of a thin film transistor is formed with an aluminum system metal having a low electric resistance, and another metal capable of anodic oxidation is deposited to prevent the aluminum system metal from producing hillocks. The metal capable of anodic oxidation and part of the aluminum system metal are changed into an insulator by an anodic oxidation treatment. In all, the gate insulator of the thin film transistor comprises three layers of aluminum oxide, an oxide of the metal capable of anodic oxidation, and silicon nitride. The method makes it possible to form the lower-layer wiring and gate electrode having a low electric resistance and a flawless gate insulator having excellent insulative quality.