Thin film transistor device having driving circuit and matrix circuit

A thin film semiconductor device, comprising:

• a substrate having a first region and a second region;
• a peripheral circuit portion formed on said substrate having a plurality of first non-memory thin film transistors, each of said first thin film transistors including,
• a polysilicon semiconductor thin film,
• a gate insulating film, and
• a gate electrode, a source electrode and a drain electrode;
• and
• a matrix circuit portion formed in the vicinity of said peripheral circuit portion by arranging on said substrate a plurality of second non-memory thin film transistors to form a matrix, each of said second thin film transistors including,
• a polysilicon semiconductor thin film,
• a gate insulating film, and
• a gate electrode, a source electrode and a drain electrode, said gate insulating film included in each of said second thin film transistors being thicker than that included in each of said first thin film transistors, said peripheral circuit portion serving to drive each of said second thin film transistors included in said matrix circuit portion;
• whereby a gate voltage to reach on-current in each of said first thin film transistors is lower than that in each of said second thin film transistors, and a gate voltage range to keep an off-current range in each of said second thin film transistors is broader than that in each of said first thin film transistors.