| 摘要 |
PURPOSE: A method for manufacturing a thin-film-transistor(TFT) for a pull-up device of a static random access memory(SRAM) is provided to guarantee a process margin in an etch process for forming a channel pattern, by forming a relatively thicker gate oxide layer in a region except a channel region than in the channel region. CONSTITUTION: A semiconductor substrate(11) wherein a metal-oxide-semiconductor(MOS) transistor and a ground voltage line are formed and an insulation layer(12) covers them, is prepared. The first poly pattern(13) functioning as a gate and a connection interconnection is formed on the insulation layer. A gate oxide layer(14) is evaporated on the first poly pattern and the insulation layer by a predetermined thickness. A nitride layer pattern blocking a region reserved for a channel region is formed on the gate oxide layer. An oxidation process is performed to make the exposed gate oxide layer relatively thicker than that of the blocked gate oxide. The nitride layer pattern is eliminated. A polysilicon layer is evaporated on the gate oxide layer having different thicknesses. Predetermined impurity ions are implanted into the polysilicon layer by using a mask for a source/drain so that a source/drain region is formed in the polysilicon layer. The polysilicon layer is patterned, and the second poly pattern(17a) functioning as a channel and a power supply voltage line is formed.
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