Enhanced polysilicon thin-film transistor performance by oxide encapsulation

An alternative TFT fabrication process employs local oxidation to eliminate adverse effects. Breakdown voltages for 60 nm thick gate insulators on 20 micron long p-channel TFTs are increased from 37.5 to 60 V. This represents a breakdown field of 11 MV/cm. Transistors with 5 micron channel lengths, which cannot be reliably fabricated using the conventional process, also exhibit breakdown fields of 11 MV/cm using this oxide isolation process. 25 refs.