Breakdown voltage

About: Breakdown voltage is a research topic. Over the lifetime, 18395 publications have been published within this topic receiving 213377 citations.

Undoped AlGaN/GaN HEMTs for microwave power amplification

Abstract: Undoped AlGaN/GaN structures are used to fabricate high electron mobility transistors (HEMTs). Using the strong spontaneous and piezoelectric polarization inherent in this crystal structure a two-dimensional electron gas (2DEG) is induced. Three-dimensional (3-D) nonlinear thermal simulations are made to determine the temperature rise from heat dissipation in various geometries. Epitaxial growth by MBE and OMVPE are described, reaching electron mobilities of 1500 and 1700 cm/sup 2//Ns, respectively, For electron sheet density near 1/spl times/10/sup 13//cm/sup 2/, Device fabrication is described, including surface passivation used to sharply reduce the problematic current slump (dc to rf dispersion) in these HEMTs. The frequency response, reaching an intrinsic f/sub t/ of 106 GHz for 0.15 /spl mu/m gates, and drain-source breakdown voltage dependence on gate length are presented. Small periphery devices on sapphire substrates have normalized microwave output power of /spl sim/4 W/mm, while large periphery devices have /spl sim/2 W/mm, both thermally limited. Performance, without and with Si/sub 3/N/sub 4/ passivation are presented. On SiC substrates, large periphery devices have electrical limits of 4 W/mm, due in part to the limited development of the substrates.

Avalanche Breakdown in Silicon

Abstract: An avalanche theory of breakdown at room temperature is proposed for semiconductors based on the assumption of approximately equal ionization rates for electrons and positive holes. The problem of obtaining ionization rates from data obtained in inhomogeneous fields is solved exactly for two specific field distributions. Ionization rates for silicon thus calculated from experimental data on breakdown voltage and on prebreakdown multiplication for both linear-gradient and step junctions are in good agreement. The temperature coefficient of the ionization rate exhibits a similar internal consistency. It is concluded that internal field emission has not been observed in silicon.Detailed observations are reported of the pulse-type noise associated with breakdown. It is shown that this noise represents the unstable onset of breakdown and that, for the junctions studied, all of the current flow in the breakdown region can be attributed to the current carried by the noise pulses.

Semiconductors for high‐voltage, vertical channel field‐effect transistors

Abstract: The influence of material parameters upon the characteristics of vertical channel power field effect transistors is examined. It is demonstrated that for devices with the same breakdown voltage and device structure, the on‐resistance is inversely proportional to the third power of the energyband gap and inversely proportional to the mobility. In addition the frequency response of these devices increases in proportion to the mobility and the energyband gap. Calculated device parameters for III–V semiconductor compounds, as well as their alloys, have been compared to those of a silicondevice with the same breakdown voltage. It is found that devicesfabricated from GaAs,InP, and GaP are expected to have a current handling capability which is a factor of 12.7, 5, and 1.85 better than that of the silicondevice with the same breakdown voltage. In addition, the current handling capability of devicesfabricated from the alloy semiconductors GaAlAs, GaAsP, and InGaP are even superior to those of a GaAsdevice with the same breakdown voltage.

Development of gallium oxide power devices

Abstract: Gallium oxide (Ga2O3) is a strong contender for power electronic devices. The material possesses excellent properties such as a large bandgap of 4.7–4.9 eV for a high breakdown field of 8 MV cm−1. Low cost, high volume production of large single-crystal β-Ga2O3 substrates can be realized by melt-growth methods commonly adopted in the industry. High-quality n-type Ga2O3 epitaxial thin films with controllable carrier densities were obtained by ozone molecular beam epitaxy (MBE). We fabricated Ga2O3 metal-semiconductor field-effect transistors (MESFETs) and Schottky barrier diodes (SBDs) from single-crystal Ga2O3 substrates and MBE-grown epitaxial wafers. The MESFETs delivered excellent device performance including an off-state breakdown voltage (Vbr) of over 250 V, a low leakage current of only few μA mm−1, and a high drain current on/off ratio of about four orders of magnitude. The SBDs also showed good characteristics such as near-unity ideality factors and high reverse Vbr. These results indicate that Ga2O3 can potentially meet or even exceed the performance of Si and typical widegap semiconductors such as SiC or GaN for ultrahigh-voltage power switching applications.

High breakdown voltage AlGaN-GaN HEMTs achieved by multiple field plates

Abstract: High-voltage Al/sub 0.22/Ga/sub 0.78/N-GaN high-electron mobility transistors have been fabricated using multiple field plates over dielectric passivation layers. The device breakdown voltage was found to increase with the addition of the field plates. With two field plates, the device showed a breakdown voltage as high as 900 V. This technique is easy to apply, based on the standard planar transistor fabrication, and especially attractive for the power switching applications.