Trap-state mapping to model GaN transistors dynamic performance

Abstract

Trapping phenomena degrade the dynamic performance of wide-bandgap transistors. However, the identification of the related traps is challenging, especially in presence of non-ideal defects. In this paper, we propose a novel methodology (trap-state mapping) to extract trap parameters, based on the mathematical study of stretched exponential recovery kinetics. To demonstrate the effectiveness of the approach, we use it to identify the properties of traps in AlGaN/GaN transistors, submitted to hot-electron stress. After describing the mathematical framework, we demonstrate that the proposed methodology can univocally describe the properties of the distribution of trap states. In addition, to prove the validity and the usefulness of the model, the trap properties extracted mathematically are used as input for TCAD simulations. The results obtained by TCAD closely match the experimental transient curves, thus confirming the accuracy of the trap-state mapping procedure. This methodology can be adopted also on other technologies, thus constituting a universal approach for the analysis of multiexponential trapping kinetics.

100 mV Ultra-Low Bias AlGaN/GaN Photodetector Based on Fin-Shaped Capacitor Configuration for Future Integrated Optoelectronics

“…These data also manifest a UV/visible rejection ratio of about 5.1 × 10 3 at a bias voltage of 100 mV. Compared to the PDCR of 7.0 × 10 4 at 100 mV, the difference between these two ratios may be originated from the trap states , related to material defects , or inevitably created during the RIE-ICP processes . Nevertheless, this ratio under low voltage still outperforms the traditional GaN Schottky photodetectors which require to operate at a much higher voltage. − …”

Stability, Reliability, and Robustness of GaN Power Devices: A Review

“…Some studies report the interface/surface trapping to dominate in the hard turn-ON process while observing the impact of buffer region design [66], [67] and drain field plate design [71] on surface trapping. Studies have also shown that the traps relevant to the hard turn-ON process possess a broadly-distributed but relatively shallow energy level [72], [73].…”

Compact Modeling of Nonideal Trapping/Detrapping Processes in GaN Power Devices

“…The full discussion of the methodology used in this article to extract the time constant distribution of the deep levels of interest can be found in [25]. Here, we provide a brief summary; considering (1), A i and τ i are the parameters of the single exponential components constituting the multiexponential threshold voltage transient.…”

“…4 shows the contour map of the time constant distribution (decay rate probability density function [26]) at different temperatures extracted from the experimentally measured V TH recovery transients in Fig. 3 following the procedure presented in [25]. It is important to stress that the extracted time constant distribution of f (t) does not have a Gaussian shape and differs from the simple derivative of the transient d f (t)/dlog(t) [27], which has no direct meaning in relation to trap properties.…”

“…Once g(ν) is defined, the trap signature distribution can be extracted from the temperature-dependent time constant distribution. As explained in [25], given a temperature-dependent time constant distribution (τ i, j , A i, j , T j ), from a set of temperature-dependent measurements, such as the one mapped in Fig. 4, a distribution of activation energies (E a,i ) and cross sections (ξ c,i ) can be uniquely extracted.…”