Patent ID: 6614076
Filing Date: 2003-09-02
Classification: G02F,H01L

Abstract:
An EL display device comprising:a pixel portion and a driver circuit for the pixel portion over one substrate; a switching thin film transistor formed in the pixel portion and including: a first semiconductor film; at least a first LDD region in the first semiconductor film; a first gate insulating film formed between the first semiconductor film and the substrate; a first gate electrode formed between the first gate insulating film and the substrate; a current controlling thin film transistor formed in the pixel portion and including: a second semiconductor film; at least a second LDD region in the second semiconductor film; a second gate insulating film formed between the second semiconductor film and the substrate; and a second gate electrode formed between the second gate insulating film and the substrate, wherein the first LDD region includes an n-type impurity at a first concentration while the second LDD region includes the n-type impurity at a second concentration, wherein the second concentration is higher than the first concentration.