Widely Adjusting the Breakdown Voltages of Kilo-Voltage Thin Film Transistors

High-voltage thin-film transistors (HV-TFTs) with designed field-plates are experimentally demonstrated to work in a wide range of kilo-voltage (kV) and with the tunable breakdown voltages (V-BD). The field plates have been placed in different positions and biased at different voltages to investigate how to effectively enhance V-BD. The largest V-BD is up to 263 % of the case without field plate and reaches 1902.5 V. By monitoring the electric potential at the end of the gated channel (V-1), it is revealed that the enhanced V-BD is associated with a reduced V-1. Therefore, the device breakdown is in fact caused by the breakdown of dielectric near the end of the gated channel in HV-TFTs rather than the destruction of semiconductor near the drain in regular TFTs. This study unveils the breakdown mechanisms of HV-TFTs and provides an effective design route for balancing the breakdown voltages and on-current of the HV-TFTs.

Automated summary

High-voltage thin-film transistors (HV-TFTs) with designed field-plates are demonstrated to work in a wide range of kilo-voltage and with tunable breakdown voltages. Investigating the placement and voltage biasing of the field plates, it is found that the enhanced breakdown voltage is associated with a reduced electric potential at the end of the gated channel. This study reveals the breakdown mechanisms of HV-TFTs and provides an effective design route for balancing breakdown voltages and on-current.