Understanding the Effects of Low-Temperature Passivation and Annealing on ZnO TFTs Test Structures

Back-gate ZnO TFTs - with and without top-side passivation - were fabricated and electrically characterized. Passivation layers consisting of HfO
₂
, Al
₂
O
₃
, and Parylene were introduced to study their impact on the TFT performance. Annealing was done to improve the electrical characteristics of passivated devices by neutralizing the initial charge introduced as a result of the low-temperature passivation. Low-temperature annealing combined with an Al
₂
O
₃
passivation layer demonstrates an I-V response comparable to ZnO TFTs without any passivation layer, indicating the viability of Al
₂
O
₃
as a good candidate for passivating ZnO TFTs.