Silicon Carbide Diodes for Microwave Applications

Abstract

Silicon carbide ( SiC ) offers significant advantages for microwave high power devises due to its unique electrical and thermal properties. This review presents a summary of the current position in the development of silicon carbide diodes operating at microwave frequencies: varactors, Schottky barrier mixer diodes, p-i-n and IMPATT diodes. Simplified theory of device operation is given for each kind of microwave diodes to derive the figures of merit, to estimate the potential silicon carbide performance for fabrication of these diodes and to compare SiC with conventional semiconductors. These analyses are followed by description of diode design, fabrication and measured characteristics.

Silicon Carbide Oscillators for Extreme Environments

“…Equation 18 shows that for the circuit to operate, the JFET needs to have a high transconductance, g m and low parasitic capacitances, C GS and C GD . This identifies the challenge of designing high temperature oscillators, in so much that in addition to the external capacitance values remaining unchanged (the parasitic capacitances within the transistor have a weak temperature dependance), the transconductance of the JFET will limit the upper operating temperature of the circuit.…”

“…Such oscillators are used in the production of high frequencies, typically in the microwave region (> 300 MHz) and above. The advantage of silicon carbide in such circuits is its ability to operate at higher temperatures than an equivalent silicon device, thus allowing designers to dissipate much higher levels of power in a circuit [18]. As shown in figure 5a a resonant circuit has the possibility to operate as an oscillator, in that it has the ability to store energy in the form of electrical oscillations if excited.…”

α-SiC nanoscale transit-time diodes: performance of the photo-irradiated terahertz sources at elevated temperature

“…On the other hand, the unique material properties of wide-bandgap (WBG) α-SiC (4H-SiC and 6H-SiC), e.g. high critical electric field (E C ), high saturation velocity of carriers (v sn,sp ) as well as high thermal conductivity (K), all combined, make these materials well suited for the high-power, high-frequency domain [13]. The benefits of such promising properties can also be quantified with respect to high-power and high-frequency applications by figure of merits (FOM).…”

Разработка технологии и исследование сверхвысокочастотных переключателей на основе 4H-SiC p-i-n-диодов

“…Благодаря большой ширине запрещенной зоны, высокой термической, химической и радиационной стойкости SiC является перспективным материалом для создания полупроводниковых приборов [1][2][3][4][5][6]. Ранее нами была продемонстрирована возможность создания переключателя на основе 4H-SiC p−i−n-диодов в диапазоне частот ∼ 10 GGHz.…”