We have made self-aligned top-gate coplanar hydrogenated amorphous-silicon (a-Si:H) thin-film transistors using a SiO2 silicone hybrid material as the gate dielectric. The hybrid dielectric layer is 150 nm thick and separates a chromium gate electrode from nickel silicide source and drain. The nickel silicide is formed by rapid thermal reaction of a deposited nickel film with the underlying a-Si:H. The electron field-effect mobility is ∼1.0 cm2V̇ s, the subthreshold slope is ∼380 mV/decade, and the on/ off current ratio is ∼105. The gate leakage current of ∼ 10 pA across the 150-nm-thick hybrid dielectric is ∼1/10 of that observed across the typical 300-nm-thick &SiNx dielectric. The whole process needs only two masks.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering
- Amorphous silicon (a-Si:H)
- SiO silicone hybrid
- coplanar top-gate thin-film transistor (TFT)
- plasma-enhanced chemical vapor deposition (PE-CVD)