Patent ID: 8530273

Claim:
A method of making a TFT substrate for an electronic device, the method comprising: sputter depositing an oxide semiconductor layer, directly or indirectly, on a soda-lime based glass substrate; depositing a gate insulator blanket layer, directly or indirectly, on the oxide semiconductor layer; depositing a gate metal blanket layer, directly or indirectly, on the gate insulator blanket layer; applying a mask over one or more portions of the gate metal blanket layer so as to define one or more corresponding masked areas and one or more corresponding unmasked areas; removing portions of the gate metal blanket layer and portions of the gate insulator blanket layer at or proximate to the one or more unmasked areas; increasing conductivity of the oxide semiconductor layer at the one or more unmasked areas then patterning the oxide semiconductor layer into a plurality of islands; disposing a passivation layer across substantially the entire substrate; patterning the passivation layer so as to define source and drain contact holes; depositing a layer for source and drain connections; and wherein all TFT processing steps are performed at or below about 150 degrees C., until a post-annealing activation step is performed at 200-250 degrees C.