METHOD FOR EXTRACTING SUBGAP DENSITY OF STATES OF AMORPHOUS OXIDE SEMICONDUCTOR THIN-FILM TRANSISTOR USING FREQUENCY-DISPERSIVE CAPACITANCE-VOLTAGE CHARACTERISTICS AND APPARATUS THEREOF

摘要

Disclosed are a method for extracting the state density in a band gap of an amorphous oxide semiconductor thin film transistor, and a device therefor. The method for extracting the state density in a band gap of an amorphous oxide semiconductor thin film transistor according to an embodiment of the present invention comprises the steps of: measuring capacitance and conductance according to gate voltage relative to predetermined frequencies; calculating local capacitance formed by a local trap in a channel based on the measured capacitance and conductance; and extracting the state density in the band gap based on the calculated local capacitance. When the local capacitance is calculated, channel conductance formed at the channel is calculated using the measured capacitance and conductance. As the local capacitance is calculated based on the calculated channel conductance, entire state density in the band gap can be simply and rapidly extracted using only experimentally measured data without iteration procedures and complicated calculation. And local capacitance and free electrons capacitance can be separated quantitatively according to the gate voltage. [Reference numerals] (AA) Start; (BB) End; (S210) Measuring conductance and capacitance according to gate voltage relative to multiple frequencies; (S220) Calculating channel conductance formed at a channel by using the measured capacitance and conductance; (S230) Calculating local capacitance (C_loc) formed by a local trap in the channel based on the calculated channel conductance; (S240) Extracting state density in a band gap based on the calculated local capacitance