94 GHz multiquantum well IMPATT diodes based on 3C-SiC/Si material system

A multiquantum well (MQW) double-drift region (DDR) impact avalanche transit time (IMPATT) device based on Si/3C-SiC material system has been proposed for high frequency application. One symmetrical and two asymmetrical doping profiles for the proposed hetero-structure device are considered in the present study. The design and optimization of the above-mentioned three doping profiles of Si/3C-SiC MQW hetero-structure DDR IMPATT diodes have been carried out by simulation technique so that the device operates at millimeter wave W-band (75-100 GHz) frequencies. The DC and large signal properties of the device are obtained from a large signal simulation program based on non-sinusoidal voltage excited model in which the density gradient theory and Böhm Potential are incorporated to provide a quantum equivalent of drift-diffusion model. The RF output power of the proposed MQW DDR IMPATTs operating at and near 94 GHz atmospheric window frequency are obtained from the simulation output and compared with the available reported values of output power for flat profile DDR IMPATT diodes at the same frequency band. The results show that among the three doping profiles of Si/3C-SiC MQW DDR IMPATT device, the asymmetrical one with higher n and p type doping concentrations of Silicon layers as compared to those of SiC layers is the preferred doping profile for better RF performance at W-band.