Pre-RF Pulse IV Measurements for Enhanced Transistor Compact Modeling Work

The trap effects induced in GaN technology impact and limit the component’s performance. These phenomena need to be taken into account in the transistor compact model. Pulsed mode measurement (also known as a single-pulse system) allows characterization of the transient effects of traps while avoiding thermal effects. The main drawback of the single-pulse system is that the charge trap levels may vary throughout the measurement due to the asymmetry of capture and emission time constants. To overcome the problem of standard or basic double-pulse techniques, a new patented measurement system that combines DC pulse signals with a variable RF pre-pulse level is proposed. This technique allows modification of the ’traps’ state of charge in a similar way to the variation of the RF signal envelope. Thus, realistic I-V measurements are obtained from this system by considering the effects of traps under conditions close to the final application. The measurement results are used to model the component’s output current source without the addition of a trap model, provided that the model is only used at the bias point set during the measurement. Therefore, the measurement conditions used for model extraction and validation are perfectly aligned, reducing the number of iterations required to fit the model on small and large signal measurements.