Improved Electrical Characteristics of Gallium Oxide/P-Epi Silicon Carbide Static Induction Transistors with UV/Ozone Treatment Fabricated by RF Sputter.

In this study, static induction transistors (SITs) with beta gallium oxide (ß-Ga2O3) channels are grown on a p-epi silicon carbide (SiC) layer via radio frequency sputtering. The Ga2O3 films are subjected to UV/ozone treatment, which results in reduced oxygen vacancies in the X-ray photoelectron spectroscopy data, lower surface roughness (3.51 nm) and resistivity (319 Ω·cm), and higher mobility (4.01 cm2V-1s-1). The gate leakage current is as low as 1.0 × 10-11 A at VGS = 10 V by the depletion layer formed between n-Ga2O3 and p-epi SiC at the gate region with a PN heterojunction. The UV/O3-treated SITs exhibit higher (approximately 1.64 × 102 times) drain current (VDS = 12 V) and on/off ratio (4.32 × 105) than non-treated control devices.

Influence of Gas Annealing on Sensitivity of AlN/4H-Sic-Based Temperature Sensors.

In this study, the physical and electrical characteristics of an AlN/4H-SiC Schottky barrier diode-based temperature sensor annealed in various gas atmospheres were investigated. An aluminum nitride (AlN) thin film was deposited on a 4H-SiC substrate via radio-frequency sputtering followed by annealing in N2 or O2 gas. The chemical composition of the film was determined by X-ray photoelectron spectroscopy (XPS) before and after annealing, and its electrical properties were evaluated by plotting a current-voltage (I-V) curve. The voltage-temperature (V-T) characteristics of the sensor were extracted from the current-voltage-temperature (I-V-T) plots constructed in the temperature range between 475 and 300 K in steps of 25 K. Sensitivities of 9.77, 9.37, and 2.16 mV/K were obtained for the as-grown, N2-annealed, and O2-annealed samples, respectively.

High-Performance Temperature Sensors Based on Dual 4H-SiC JBS and SBD Devices.

Schottky diode-based temperature sensors are the most common commercially available temperature sensors, and they are attracting increasing interest owing to their higher Schottky barrier height compared to their silicon counterparts. Therefore, this paper presents a comparison of the thermal sensitivity variation trend in temperature sensors, based on dual 4H-SiC junction barrier Schottky (JBS) diodes and Schottky barrier diodes (SBDs). The forward bias current-voltage characteristics were acquired by sweeping the DC bias voltage from 0 to 3 V. The dual JBS sensor exhibited a higher peak sensitivity (4.32 mV/K) than the sensitivity exhibited by the SBD sensor (2.85 mV/K), at temperatures ranging from 298 to 573 K. The JBS sensor exhibited a higher ideality factor and barrier height owing to the p-n junction in JBS devices. The developed sensor showed good repeatability, maintaining a stable output over several cycles of measurements on different days. It is worth noting that the ideality factor and barrier height influenced the forward biased voltage, leading to a higher sensitivity for the JBS device compared to the SBD device. This allows the JBS device to be suitably integrated with SiC power management and control circuitry to create a sensing module capable of working at high temperatures.

Study on 3.3 kV Super Junction Field Stop Insulated Gate Bipolar Transistor According to Design and Process Parameters.

In this paper, we analyzed the electrical characteristics of 3.3 kV super junction FS IGBT as next generation power device by structural design. The device parameters were extracted by design and process simulation. Especially, to obtain optimal breakdown voltage, we researched the breakdown characteristic. To begin with, we confirmed that the breakdown voltage was decreased as trench depth was increased. And we analyzed the breakdown voltage according to p-pillar dose. As a result of experiment, we confirmed that the breakdown voltage was increased as p-pillar dose was increased. To obtain over 3.3 kV, the dose of p-pillar was 5×1013 cm-2, the resistivity of epi layer was 140 Ω·cm. We will extract design and process parameters considering on state voltage drop.