Method for calculating parameter values of thin-film transistor and apparatus for performing the method

1. A method for calculating values of parameters of a thin film transistor (TFT), the method comprising:

calculating, using a computer, a set of simulated current-voltage (I-V) values using state-density-functions over an entire energy band in a band gap of an amorphous semiconductor of the TFT;

comparing, using the computer, the set of simulated I-V values with a set of measured I-V values of the TFT to determine a value of a parameter of the TFT; and

determining values of a donor state-density-function g D and values of an interface state-density-function D it over the entire energy band in the band gap.

2. The method of claim 1 , further comprising:

calculating values of an acceptor state-density-function g A using a set of electrostatic capacity-voltage (C-V) values of the TFT measured according to a frequency of TFT.

3. The method of claim 2 , wherein the acceptor state-density-function g A comprises an acceptor-like tail state-density-function and an acceptor-like deep state-density-function,

the donor state-density-function g D comprises a donor-like tail state-density-function g TD and a shallow donor state-density-function g OV , and

the interface state-density-function D it comprises an acceptor-like state-density-function D itA and a donor-like state-density-function D itD .

4. The method of claim 2 , wherein in determining the value of the parameter of the TFT, values of a plurality of parameters of the state-density-functions applied for calculating the simulated I-V value are determined as the values of the parameters of the TFT when the set of simulated I-V values is equal to the set of measured I-V values.

5. The method of claim 4 , further comprising controlling the donor state-density-function g D and the interface state-density-function D it to make the set of simulated I-V values become equal to the set of measured I-V values when the set of simulated I-V values is different from the set of measured I-V values.

6. The method of claim 4 , further comprising:

calculating a set of simulated generation-recombination current (I G-R ) values using the state-density-functions when the set of simulated I-V values is equal to the set of measured I-V values.

7. The method of claim 6 , wherein in determining the value of the parameter of the TFT,

values of a plurality of parameters of the state-density-functions applied for calculating the set of simulated I G-R values is determined as the values of the parameters of the TFT when the set of simulated I G-R values is equal to a set of measured I G-R values.

8. The method of claim 6 , further comprising controlling the donor state-density-function g D and the interface state-density-function D it make the set of simulated I G-R values become equal to a set of measured I G-R values when the set of simulated I G-R values is different from the set of measured I G-R values.

9. A method for calculating values of parameters of a thin film transistor (TFT), the method comprising:

calculating, using a computer, a set of simulated current-voltage (I-V) values using state-density-functions over an entire energy band in a band gap of an amorphous semiconductor of the TFT; and

comparing, using the computer, the set of simulated I-V values with a set of measured I-V values of the TFT to determine a value of a parameter of the TFT, wherein calculating the set of simulated current-voltage (I-V) values comprises:

calculating a flat band voltage (V FB ) using the state-density-functions in a flat band condition;

calculating a density of an electrical charge, an electric field, and an electric potential of the amorphous semiconductor using the flat band voltage; and

calculating a subset of simulated I-V values using the density of the electrical charge, the electric field, and the electric potential.

10. A calculating apparatus for calculating values of parameters of a TFT, the calculating apparatus comprising:

a calculating part calculating a set of simulated I-V values using state-density-functions over an entire energy band in a band gap of an amorphous semiconductor of the TFT;

a determining part comparing the set of simulated I-V values with a set of measured I-V values of the TFT to determine values of a plurality of parameters of the TFT;

a non-transitory storage medium storing computer readable code that is configured for performing tasks related to at least one of the calculating part and the determining part; and

a parameter controller determining values of a donor state-density-function g D and values of an interface state-density-function D it over the entire energy band in the band gap,

wherein the calculating part calculates the set of simulated I-V values using an acceptor state-density-function g A , the donor state-density-function g D , and the interface state-density-function D it .

11. The calculating apparatus of claim 10 , wherein the calculating part calculates values of an acceptor state-density-function g A using a set of electrostatic capacity-voltage (C-V) values of the TFT measured according to a frequency of TFT.

12. The calculating apparatus of claim 11 , wherein the acceptor state-density-function g A comprises an acceptor-like tail state-density-function and an acceptor-like deep state-density-function,

the donor state-density-function g D comprises an donor-like tail state-density-function g TD and an shallow donor state-density-function g OV , and

the interface state-density-function D it comprises an acceptor-like state-density-function D itA and a donor-like state-density-function D itD .

13. The calculating apparatus of claim 11 , wherein the determining part determines values of a plurality of parameters of the state-density-functions applied for calculating the simulated I-V value as the values of the parameters of the TFT when the set of simulated I-V values is equal to the set of measured I-V values.

14. The calculating apparatus of claim 13 , wherein the parameter controller controls the donor state-density-function g D and the interface state-density-function D it to make the set of simulated I-V values become equal to the set of measured I-V values when the set of simulated I-V values is different from the set of measured I-V values.

15. The calculating apparatus of claim 13 , wherein the calculating part calculates a set of simulated I G-R values of the TFT using the state-density-functions when the set of simulated I-V value is equal to the set of measured I-V values.

16. The calculating apparatus of claim 15 , wherein the determining part determines values of a plurality of parameters of the state-density-functions applied for calculating the set of simulated I G-R values as the values of the parameters of the TFT when the set of simulated I G-R values is equal to a set of measured I G-R values.

17. The calculating apparatus of claim 15 , wherein the parameter controller controls the donor state-density-function g D and the interface state-density-function D it to make the set of simulated I G-R values become equal to a set of measured I G-R values, when the simulated I G-R value is different from the set of measured I G-R values.

18. The calculating apparatus of claim 10 , wherein the calculating part calculates a flat band voltage (V FB ) using the state-density-functions in a flat band condition, calculates a density of an electrical charge, an electric field, and an electric potential using the flat band voltage (V FB ), and calculates a subset of I-V values using the density of the electrical charge, the electric field, and the electric potential.