We report effects for up to 100 Mrad (SiO2) gamma-ray exposure on polycrystalline ZnO thin film transistors (TFTs) deposited by two different techniques. The radiation related TFT changes, either with or without electrical bias during irradiation, are primarily a negative VON shift and a smaller VT shift (Δ VON ∼ - 2.5V and Δ VT ∼ - 1.5V for 100 Mrad (SiO2) exposure). Field-effect mobility remains nearly unchanged. Both, VON and VT shifts are nearly completely removed by annealing at 200°C for 1 minute and some recovery is seen even at room temperature. We find that our ZnO TFTs are insensitive to electrical bias during irradiation; that is, unbiased measurements are useful worst case test results. To the best of our knowledge, these are the most radiation-hard thin film transistors reported to date.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Nuclear Energy and Engineering
- Electrical and Electronic Engineering