Analysis of metal and zinc oxide semiconductor interface resistance using transmission line method

Abstract

The transmission line method (TLM) is modified to analyze the contact resistance between the metal and zinc oxide semiconductor considering interface resistance. TCAD is used to simulate an ideal defect-less state and compare it with experimental result. It is found that the current transfer length can be overestimated in conventional TLM measurement. The importance of interface resistance is shown through interface trap and Schottky contact effect analysis: Resistance comparison between different metal used device, and the activation energy shift measurement after O2 pre-annealing. Based on these, the conventional resistance equation for TLM is corrected by separating channel resistance and non-ideal contact resistance. The mobility and temperature coefficient of resistance (TCR) of ZnO channel are extracted using the suggested method. This shows the importance of metal/semiconductor interface resistance in devices using semiconductor channel.