Comprehensive depletion-mode modeling of oxide thin-film transistors

Graduation date: 2015The primary focus of this thesis is modifying the comprehensive depletion-mode model and extending its applicability to p-channel thin-film transistor (TFT) behavior and subthreshold (subpinchoff) operation. The comprehensive depletion-mode model accurately describes depletion-mode TFT behavior and establishes a set of equations, different from those obtained from square-law theory, which can be used for carrier mobility extraction.\ud In the modified comprehensive depletion-mode model, interface mobility (mu_interface ) and bulk mobility (mu_bulk ) are distinguished. Simulation results reveal that when square-law theory mobility extraction equations are used to assess depletion-mode TFTs, the estimated interface mobility is often overestimated. In addition, the carrier concentration of a thin channel layer can be estimated from an accurate fitting of measured depletion-mode TFT current-voltage characteristics curves using the comprehensive depletion-mode model