부산대학교 도서관

In this paper, we characterize the signature of traps existing in the new AlGaN/GaN HEMT of 0.15- $\mu \text{m}$ ultrashort gate length and $8 \times 50\,\,\mu \text{m}^{2}$ gate width (GH15) through three different measurement techniques which are low frequency (LF) S-parameters, drain-current deep level transient spectroscopy (I-DLTS), and LF drain noise characterization. These three different measurements techniques were performed for varying chuck temperatures ( $T_{\mathrm {chuck}}$ ) ranging between 25 °C and 125 °C and for the same biasing condition. All measurements ensure approximatively the extraction of the same signature of traps [apparent activation energy ( $E_{a}$ ) and cross section ( $\sigma _{n}$ )] existing in the UMS device. Furthermore, we have characterized the thermal resistance ( $R_{\mathrm {TH}}$ ) using pulsed $I$ – $V$ measurement and a two-step calibration process. The determination of $R_{\mathrm {TH}}$ is important to evaluate the device and to know precisely the signature of traps $E_{a}$ and $\sigma _{n}$ defined by the Arrhenius equation. A large signal measurements using an unequally spaced multitone (USMT) signal were done in order to evaluate the performance of GH15 transistor around the optimum load impedance in terms of efficiency (max PAE ~ 55%). The leakage current which measured before and after all measurements for $V_{\mathrm {GS}} = -6$ , −7 V and for $V_{\mathrm {DS}}$ varying from 0 to 10 V was lower than $100~\mu \text{A}$ /mm. To our knowledge, results on charge-trapping and large-signal performance are reported for the first time in 0.15- $\mu \text{m}$ technology.