Patent ID: 6960809

Claim:
A polysilicon thin film transistor, comprising: a poly-island layer; a gate over the poly-island layer; a gate insulation layer between the gate and the poly-island layer; and an inter-layer dielectric layer, wherein the inter-layer dielectric layer includes an oxide layer and a nitride layer, the oxide layer covers the gate and the gate insulation layer and the nitride layer is over the oxide layer, the oxide layer and the nitride layer of the inter-layer dielectric layer have a thickness relationship given by the following inequality: T OX ≧(T nitride ×9000 Å) 1/2 , where T OX represents the thickness of the oxide layer (in Å), T nitride represents thickness of the silicon nitride layer and that thickness of the nitride layer is between 50 Å and 1000 Å.