PURPOSE: To provide a method for forming a polysilicon gate on a glass substrate in the manufacture of polysilicon thin film transistors.

CONSTITUTION: The title method for the manufacture of thin film transistors consists of two processes: In the first process, a first polysilicon film 2, gate insulating film 3 and second polysilicon film 4 are deposited on an insulating substrate 1 in this order. In the second process, the second polysilicon film 4 is etched to form a gate electrode 4a, and ions, not subjected to mass separation, are implanted in the entire surface to reduce the resistance of the gate electrode 4a. Further, impurities are implanted into the first polysilicon film 2 on both sides of the gate electrode 4a to form the source 2a and drain 2b. A glass substrate is used for the insulating substrate 1. The first polysilicon film 2, gate insulating film 3 and second polysilicon film 4 are formed at a temperature of 650°C or below. For the mass-unseparated ion implantation, the insulating substrate l is heated to a temperature lower than the temperature of the gate insulating film 3 formation.