Investigation of gate leakage current mechanism in AlGaN/GaN high-electron-mobility transistors with sputtered TiN

Abstract

The gate leakage current mechanism of AlGaN/GaN Schottky barrier diodes (SBDs) and highelectron-mobility transistors (HEMTs) with sputtered TiN is systematically investigated. The reverse leakage current (J R ) of TiN SBDs increases exponentially with the increase of reverse voltage (V R ) from 0 to À3.2 V (Reg. I). This conduction behavior is dominated by Poole-Frenkel emission from TiN through an interface state of 0.53 eV to the conductive dislocation-related continuum states. The obtained interface state of 0.53 eV may be due to the plasma damage to the surface of the AlGaN/GaN HEMT structure during the TiN sputtering. When the TiN SBDs are biased with À20 < V R < À3.2 V, J R saturated due to the depletion of the 2-dimensional electron gas (2DEG) channel (Reg. II). This conduction behavior is dominated by the trap-assisted tunneling through the interface state at $0.115 eV above the Fermi level. The three terminal OFF-state gate leakage current of AlGaN/GaN HEMTs exhibited an activation energy of 0.159 eV, which is in close agreement with the obtained interface state of $0.115 eV from saturated J R (Reg. II) of the SBDs. The observation of the negative temperature coefficient (À1.75 V/K) from the OFF-state breakdown voltage (at 1 lA/mm) of AlGaN/GaN HEMTs is due to the trap-assisted tunneling mechanism, which is also well correlated with the conduction mechanism realized from the reverse leakage current of the SBDs.

Schottky Contacts to ZnO-Nanocoated SnSe Powders by Atomic Layer Deposition

“…The increase in current values with the temperature, shown in Figure , indicates that the thermal activation process with an exp ( − E A / k T ) dependence, where E A is the activation energy, contributed to the current conduction Figure a shows the plots of reverse current versus 1/ kT at −1 V. From the linear fits to these plots, the E A values corresponding to the effective energy barrier for current conduction could be obtained.…”

“…A dependence, where E A is the activation energy, contributed to the current conduction. 37 Figure 5a shows the plots of reverse current versus 1/kT at −1 V. From the linear fits to these plots, the E A values corresponding to the effective energy barrier for current conduction could be obtained. Figure 5b shows the E A values at different bias voltages, thus indicating the highest values for the SnSe sample with ZnO 100 cycles.…”

Switching properties of epitaxial La0.5Sr0.5CoO3/Na0.5Bi0.5TiO3/La0.5Sr0.5CoO3 ferroelectric capacitor

“…Four kinds of leakage mechanisms have been proposed for ferroelectric perovskite oxides: the ohmic conduction, the bulklimited space-charge-limited conduction (SCLC), the bulklimited Poole-Frenkel emission and the interface-limited Schottky emission. [25][26][27][28] Fig. 4 shows the relationship between the leakage current density J and the electric eld E for the LSCO/NBT/LSCO ferroelectric capacitor.…”

The Evolution of Manufacturing Technology for GaN Electronic Devices

“…The role of Ti/Al diffusion-type ohmic contact metals in the process of reducing the interface energy barrier is explained by several studies in the literature [ 61 , 62 , 63 , 64 ]. When rapid thermal annealing (RTA) is used, and the maximum temperature is raised to above 800 °C, Ti/Al can diffuse into the GaN layer and form a uniform TiAlN alloy.…”