MOSFET Unity Gain Frequency Prediction Using In-Line DC Parameters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for predicting unity gain frequency in MOSFETs are inefficient due to high characterization times and costly S-parameter measurements, which restrict productivity in manufacturing lines and require large, space-constrained equipment.
Innovation Solution
A method involving the measurement of in-line direct current parameters at different drain voltages to extract transconductance and total gate capacitance, allowing for the prediction of unity gain frequency without the need for S-parameter measurements, using a combination of DC parameter measurements and calibration models.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If S-parameter measurements are used to predict unity gain frequency, then measurement precision is improved, but characterization time increases and productivity decreases
Solution Approach 1:
The patent extracts only the essential DC parameters (transconductance Gm and gate capacitance Cgg) needed to predict unity gain frequency, rather than performing complete S-parameter measurements. This extraction approach maintains sufficient prediction accuracy while dramatically reducing measurement time and increasing manufacturing productivity.
Solution Approach 2:
The patent segments the unity gain frequency prediction process into two stages: (1) calibration phase where S-parameters are measured to establish correlation models, and (2) production phase where only simple DC parameters are measured. This segmentation allows complex measurements to be performed only once during calibration, while routine production uses simplified measurements.
2Measurement precision
If S-parameter measurement tools are used, then measurement precision is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent extracts only the essential DC parameters (transconductance Gm and gate capacitance Cgg) needed to predict unity gain frequency, rather than performing complete S-parameter measurements. This extraction approach maintains sufficient prediction accuracy while dramatically reducing measurement time and increasing manufacturing productivity.
Solution Approach 2:
The patent creates a simplified measurement model that copies only the essential characteristics needed for unity gain frequency prediction. Instead of using the full complex S-parameter measurement system, a simplified DC parameter measurement system is designed that replicates the necessary information for accurate prediction.
3Measurement precision
If S-parameter measurements are performed, then unity gain frequency prediction accuracy is improved, but measurement time increases
Solution Approach 1:
The patent performs preliminary calibration using complete S-parameter measurements to establish correlation models between DC parameters and unity gain frequency. Once calibrated, the system uses only simple DC parameter measurements for routine predictions, eliminating the need for time-consuming S-parameter measurements during production while maintaining accuracy through the pre-established models.
4Measurement precision
If large S-parameter structures are placed in the manufacturing line, then measurement capability is improved, but available space decreases
Solution Approach 1:
The patent extracts only the essential DC parameters (transconductance Gm and gate capacitance Cgg) needed to predict unity gain frequency, rather than performing complete S-parameter measurements. This extraction approach maintains sufficient prediction accuracy while dramatically reducing measurement time and increasing manufacturing productivity.
Solution Approach 2:
The patent creates a simplified measurement model that copies only the essential characteristics needed for unity gain frequency prediction. Instead of using the full complex S-parameter measurement system, a simplified DC parameter measurement system is designed that replicates the necessary information for accurate prediction.
Data Source
AI summary
Various embodiments include approaches for predicting unity gain frequency in a MOSFET. In some cases, a method includes predicting a unity gain frequency (fT) in a MOSFET device in a manufacturing line, the method including: measuring a first set of in-line direct current (DC) parameters of the MOSFET on the manufacturing line at a first drain voltage (Vd1); extracting a transconductance (Gm) from the first set of in-line DC parameters as a function of a gate-voltage (Vg) and the first drain-voltage (Vd1); measuring a second set of in-line DC parameters of the MOSFET on the manufacturing line at a second drain voltage (Vd2); extracting a total gate capacitance (Cgg) from the second set of in-line DC parameters as a function of the gate-voltage (Vg); and predicting the unity gain frequency (fT) of the MOSFET based upon the extracted transconductance (Gm) and the extracted total gate capacitance (Cgg).