Amorphous Semiconductor TFT Parameter Calculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in accurately quantifying the changes in properties of amorphous metal oxide semiconductors under electrical, optical, and thermal stresses to anticipate their performance in actual pixel operating environments, as existing methods fail to define these changes effectively.
Innovation Solution
A method and apparatus for calculating parameters of thin-film transistors (TFTs) using simulated current-voltage (I-V) values, state-density-functions, and generation-recombination current (IG-R) values, which compare measured and simulated values to determine parameters such as acceptor and donor state-density-functions and interface state-density-functions, allowing for the simulation of electrical properties under various stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to form amorphous semiconductor structures, then manufacturing cost is reduced and deposition temperature is lowered, but the ability to quantitatively anticipate property changes under electrical, optical, and thermal stresses is insufficient
Solution Approach 1:
The patent applies preliminary action by pre-defining multiple stress conditions (electrical stress with various voltages and waveforms, optical stress with different light sources, thermal stress with temperature variations) and property types (mobility, threshold voltage, subthreshold swing) before actual simulation. This allows the system to comprehensively anticipate property changes under various stresses without requiring complex real-time calculations during operation.
Solution Approach 2:
The patent segments the property simulation into distinct categories: electrical properties (mobility, threshold voltage), optical properties (light absorption), and thermal properties (temperature effects). Each property type is calculated separately under specific stress conditions, allowing the complex simulation task to be divided into manageable segments that can be systematically analyzed and combined.
2Ease of manufacture
If amorphous semiconductor is used instead of single crystalline semiconductor, then deposition temperature is reduced and manufacturing cost is lowered, but the band structure becomes unclear and valance electrons are harder to control
Solution Approach 1:
The patent applies parameter changes by systematically varying deposition parameters (temperature, pressure, gas flow rates) and post-deposition treatment parameters (annealing temperature, time, atmosphere) to optimize the amorphous semiconductor film properties. This allows control over the band structure and valance electron characteristics while maintaining the manufacturing advantages of amorphous materials.
Data Source
AI summary
A method for calculating values of parameters of a TFT includes calculating 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. The method further includes comparing 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. The method may further include calculating values of an acceptor state-density-function gA using a set of electrostatic capacity-voltage (C-V) values of the TFT measured according to a frequency. The method may further include determining values of a donor state-density-function gD and values of an interface state-density-function Dit over the entire energy band in the band gap.