In this article, we have systematically investigated the effect of annealing of fabricated GaN Schottky barrier diodes (SBDs) and anode metals with various work-functions on the performance of AlGaN/GaN SBDs. It is found that after annealing of fabricated GaN SBDs, the interface states between the metal and GaN etching surface are suppressed, the device stability is enhanced, and the turn-on voltage ( ${\mathrm {V}}_{ \mathrm{\scriptscriptstyle ON}}$ ) shows negligible degradation. Meanwhile, high-performance AlGaN/GaN SBDs with various work-function metals as anode have been achieved by adapting the annealing treatment. The calculated Schottky barrier heights of the fabricated SBDs with Cr, W, and Ni anode is 0.27, 0.68, and 0.98 eV, respectively, which are almost the same as those estimated from XPS measurements. A low turn-on voltage of 0.42 V and low leakage current of $0.3~\mu \text{A}$ /mm are obtained by using the low work-function metal W (4.6 eV) as anode. Furthermore, the SBDs fabricated with the high work-function metal Ni (5.1 eV) shows an extremely low-leakage current of 6 nA/mm and exhibit a current ON/OFF ratio of $10^{{9}}$ while also showing great characteristics at high temperature.

In this letter, we report on demonstrating high-performance lateral GaN Schottky barrier diode (SBD) on silicon substrate with low turn-on voltage ( $\text{V}_{\mathbf {on}}$ ), high breakdown voltage (BV) with low reverse leakage current ( $\text{I}_{\mathbf {R}}$ ), and high power figure of merit (P-FOM) through anode engineering technique. Lateral GaN SBD with anode-cathode distance ( $\text{L}_{\mathbf {AC}}$ ) of $25~\mu \text{m}$ demonstrates a $\text{V}_{\mathbf {on}} =0.38$ V, a BV of >3 kV at a $\text{I}_{\mathbf {R}}$ of $10\mu \text{A}$ /mm and differential specific ON-resistance ( $\text{R}_{\mathbf {on,sp}}$ ) of 2.94 $\text{m}\Omega ~\cdot $ cm2, yielding a high P-FOM of more than 3 GW/cm2. To the best of our knowledge, this P-FOM is the highest value among all the GaN SBDs on any substrates. Combining with 5 A forward current ( $\text{I}_{\mathbf {F}}$ ) and reverse BV >2 kV of a large periphery device with perimeter of 20 mm, GaN SBD with anode engineering technique shows its great promise for next generation power electronics.

We demonstrate high-performance AlGaN/GaN lateral Schottky barrier diodes (SBDs) with Mo anode and low turn-on voltage of 0.31 V. AlGaN/GaN SBDs with anode to cathode spacing of 6/10/15/20/25 mu m achieve a breakdown voltage (BV) of 0.83/1.23/1.62/2.46/2.65 kV, yielding a power figure-of-merit (FOM) of 1.53/1.82/1.77/2.65/2.12 GW cm(-2). The power FOM of 2.65 GW cm(-2) and BV of 2.65 kV are the best results of AlGaN/GaN SBDs on silicon substrate. Combined with the good dynamic performance with only 10% R-on increase when switched from a -600 V stress for 10 ms, GaN SBDs verify their great promise for future power electronic applications. (C) 2019 The Japan Society of Applied Physics

In this letter, we report the achievement of a high-performance lateral GaN Schottky barrier diode (SBD) on a silicon substrate with a low turn-ON voltage (V-ON) of 0.35 V and tungsten (W) as the anode. Non-field-plated lateral GaN SBDs with the anode-cathode distances (L-AC) of 6, 10, 15, 20, and 25 mu m demonstrate the reverse breakdown voltages of 0.6, 1.1, 1.25, 1.5, and 1.9 kV with the differential specific ON-resistances (R-ON,R-sp) of 0.38, 0.72, 1.23, 1.87, and 2.61 m Omega.cm(2), respectively. The power figure-of-merit (FOM) is calculated to be 1 x 10(3), 1.7 x 10(3), 1.3 x 10(3), 1.2 x 10(3), and 1.4 x 10(3) MW/cm(2). To the best of our knowledge, this FOM of 1.7 x 10 3 MW/cm(2) is the highest among all the lateral GaN SBDs on a Si substrate. Combined with the similar to 10(8) current ON/OFF ratio at room temperature, the GaN SBD with the W anode shows a great promise for next-generation power electronics.

In this paper, we demonstrate that a Schottky drain can improve the forward and reverse blocking voltages（BVs）simultaneously in AlGaN/GaN high-electron mobility transistors（HEMTs）. The mechanism of improving the two BVs is investigated by analysing the leakage current components and by software simulation. The forward BV increases from72 V to 149 V due to the good Schottky contact morphology. During the reverse bias, the buffer leakage in the Ohmicdrain HEMT increases significantly with the increase of the negative drain bias. For the Schottky-drain HEMT, the buffer leakage is suppressed effectively by the formation of the depletion region at the drain terminal. As a result, the reverse BV is enhanced from-5 V to-49 V by using a Schottky drain. Experiments and the simulation indicate that a Schottky drain is desirable for power electronic applications.

In this paper, the influence of a drain field plate (FP) on the forward blocking characteristics of an AlGaN/GaN high electron mobility transistor (HEMT) is investigated. The HEMT with only a gate FP is optimized, and breakdown voltage VBR is saturated at 1085 V for gate—drain spacing LGD ≥ 8 μm. On the basis of the HEMT with a gate FP, a drain FP is added with LGD = 10 μm. For the length of the drain FP LDF ≤ 2 μm, VBR is almost kept at 1085 V, showing no degradation. When LDF exceeds 2 μm, VBR decreases obviously as LDF increases. Moreover, the larger the LDF, the larger the decrease of VBR. It is concluded that the distance between the gate edge and the drain FP edge should be larger than a certain value to prevent the drain FP from affecting the forward blocking voltage and the value should be equal to the LGD at which VBR begins to saturate in the first structure. The electric field and potential distribution are simulated and analyzed to account for the decrease of VBR.