Evaluation of a Gate-First Process for AlGaN/GaN Heterostructure Field-Effect Transistors

Abstract

In this study, we evaluated the annealing temperature and time-dependent electrical properties of AlGaN/GaN heterostructure field-effect transistors (HFETs) utilizing TiN/W/Au as the gate electrode. With the annealing temperature increasing from 750 to 900 °C for the annealing time of 1 min, the sheet resistance of TiN/W/Au films increased gradually while that of the ohmic contact was minimum (0.66 Ω mm) at 800 °C. From the current–voltage characteristics of the Schottky diode and HFETs, it is demonstrated that annealing at 800 °C showed the lowest on-resistance and highest maximum drain current. By prolonging the annealing from 0.5 to 10 min at 800 °C, good device performance was achieved when the annealing time was 1 and 3 min, while the device performance degraded showing an increased gate leakage current and gate resistance with increasing annealing time. These results demonstrated that the TiN/W/Au gate, which can withstand 800 °C annealing for a short time, is suitable for application in the gate-first process for AlGaN/GaN HFETs.

Synthesis of titanium nitride for self-aligned gate AlGaN/GaN heterostructure field-effect transistors

“…It is noticed that an appropriate ohmic contact resistance of about 0.7 Ω mm can be obtained at 800°C under a mediate time of 1 or 3 min, and the sheet resistance of the gate film accreted slightly from about 0.47 to 0.67 Ω/□ when prolonging the annealing time to 10 min [ 16 ]. Figure 4 a shows the I - V characteristics of HFETs for different annealing times (0.5, 1, 3, and 10 min) at 800°C.…”

GaN Schottky Barrier Diode With TiN Electrode for Microwave Rectification

“…Some metal nitrides, such as TiN, TaN, MoN, and MoSiN, are possible candidates to develop Schottky contact on GaN due to their favorable work functions, low resistivity, thermal stability, and compatibility with high-k dielectric [13], [14]. We have also found that TiN/W/Au gate stack structure on AlGaN/GaN heterostructure field-effect transistors (HFETs) showed good thermal stability even at the temperature of 800 • C [15]. In this paper, we will report GaN SBDs for microwave rectification with a low turn-on voltage by using reactively-sputtered TiN as the Schottky electrode.…”

Effect of geometry on the sensing mechanism of GaN Schottky barrier diode temperature sensor

“…However, the work temperature is only tested to 200 °C. In our previous work, we have confirmed that TiN/GaN Schottky contact presented good rectification characteristics after 850 °C annealing for 10 minutes [29][30][31]. Therefore, we believe that the TiN anode GaN SBD has the potential to sense higher temperatures (T>600 K).…”