Characteristics of Schottky Rectifier Diodes Based on Silicon Carbide at Elevated Temperatures
- PDF / 297,235 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 55 Downloads / 251 Views
ICS OF SEMICONDUCTOR DEVICES
Characteristics of Schottky Rectifier Diodes Based on Silicon Carbide at Elevated Temperatures A. M. Strel’chuka,*, A. A. Lebedeva, and P. V. Bulatb a Ioffe
b
Institute, St. Petersburg, 194021 Russia Sevastopol State University, Sevastopol, 299053 Russia *e-mail: [email protected]
Received July 23, 2020; revised July 27, 2020; accepted July 27, 2020
Abstract—Forward and reverse current–voltage characteristics of commercial rectifier diodes based on a Schottky barrier to 4H-SiC are studied in the temperature range 20–370°C at a maximum current of 10– 20 mA and maximum voltage of 10–100V. It is found that the diodes can be considered nearly ideal with a Schottky-barrier height of ~1.5 eV, with the forward current over the entire temperature range and the reverse current at high temperatures being largely due to thermionic emission. The upper limit of the working temperature range of 4H-SiC-based Schottky rectifier diodes at the currents and voltages under study approximately corresponds to the fundamental limit determined by the barrier height. In the reported experiment it reaches 370°C. Keywords: silicon carbide, rectifying diode, Schottky barrier, high temperature DOI: 10.1134/S1063782620120374
1. INTRODUCTION Silicon carbide has a substantially wider band gap Eg (~3 eV for hexagonal SiC polytypes) as compared with most widely used semiconductor materials Si, GaAs, GaP (Eg within the range 1–2.4 eV). As a consequence, the upper limit of the working temperatures of rectifying diodes based on a p–n junction in SiC was expected to be substantially higher than that with the above-mentioned materials [1]. The standard temperature range in the testing of packaged and unpackaged p–n structures based on SiC under atmospheric conditions is from 20°C to 300–500°C, with the high-temperature limit commonly determined by the characteristics of the case or the metal on the surface of SiC, rather than by the semiconductor. We have shown that the rectifying capacity of diodes having the form of 6H-SiC-based p–n structures is retained in vacuum (~10–5 mm Hg) up to a temperature of 800°C, with qualitative correspondence observed between the characteristics of the known generation–recombination model in wide-gap semiconductors at low currents [2]. At present, rectifying diodes based on a Schottky barrier to 4H-SiC are commercially available. In this work, we present the results obtained upon studying the current–voltage (I–V) characteristics of CPW20650-S010B rectifying diodes based on 4H-SiC, with a doping level of the n-type base layer of ~6 × 1015 cm–3.
The diodes are chips with a Schottky barrier area of 2.7 × 10–2 cm2. The forward and reverse I–V characteristics were examined in the temperature range 20– 370°C under atmospheric conditions. The current was measured with a 6485 KEITHLEY picoammeter up to maximum currents of 10–20 mA, at which the series differential resistance Rs of a forward-biased diode was calculated. The reverse current was measured up to maximum reverse voltage
Data Loading...
