| 摘要 |
High voltage tolerant thin film transistors (TFTs) may be formed during a dual work function polysilicon process used to fabricate poly-poly capacitors with substantially no additional process complexity. Polysilicon lower plate material is patterned in those areas targeted for TFT formation into source, drain, and channel regions. In one embodiment, TFT source and drain regions are doped to the same conductivity as capacitor lower plate regions while TFT channel regions are not doped. In another embodiment, TFT channel regions are lightly doped with positively charged ions. Capacitor dielectric material is used to form TFT gate structures. Capacitor top plate silicon provides TFT gate connection surfaces.
|
