Studies on anisotype Si/Si 1-x Ge x heterojunction DDR IMPATTs: efficient millimeter-wave sources at 94 GHz window

In this paper, the quantum mechanical behavior of a reverse biased nano-scale p-n junction based on Si/Si 0.4 Ge 0.6 /Si quantum well has been studied by obtaining the self-consistent solution of coupled Schrödinger and Poisson equations. The carrier confinement within the said quantum well structure has been investigated by analyzing the special variations of electron and hole densities throughout the device structure obtained from the self-consistent solution of coupled Schrödinger and Poisson equations for different widths of the quantum well. The tunnel current across the junction has also been calculated for the heterostructure for different applied reverse bias voltages. Results show that, due to the greater depth of the quantum well in conduction band as compared to that in valance band of Si/Si 0.4 Ge 0.6 /Si heterostructure, the quantum confinement effect is more pronounced for electrons in conduction band as compared to that for holes in valance band. Finally the current-voltage characteristics of the heterostructure under consideration have been investigated for different widths of the quantum well. It is observed that the modulation of tunnel current may be achieved by varying the width of the quantum well. The present study is the groundwork for investigating the optoelectronic properties of nano-scale photodetectors based on Si/Si 1−x Ge x /Si material system capable of detecting longer wavelengths around 1.30 and 1.55 μm.

Section: Calculation Of Tunnel Current Densitymentioning

confidence: 99%

Self-consistent solution of Schrödinger–Poisson equations in a reverse biased nano-scale $$p$$ p - $$n$$ n junction based on $$\hbox {Si/Si}_{0.4}\hbox {Ge}_{0.6}/\hbox {Si}$$ Si/Si 0.4 Ge 0.6 / Si quantum well

Acharyya¹,

Chatterjee²,

Das³

et al. 2014

J Comput Electron

Self Cite

“…Some wide bandgap (WBG) semiconductors such as SiC, GaN and diamond are recently being explored as potential base materials for high power IMPATT diodes at higher mmwave and terahertz frequency bands (0.1 -10 THz) [5,6]. Hetero-junction, superlattice and MQW structures of IMPATTs have been reported and their DC and RF characteristics have been studied either analytically or simulation techniques [7][8][9][10][11]. The advantages of the heterojunction IMPATTs over conventional homojunction devices are reduced avalanche noise and higher output power with higher DC to RF conversion efficiency at mm-wave frequency bands.…”

Section: Introductionmentioning

confidence: 99%

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

Acharya

Proceedings of the 2015 Third International Conference on Computer, Communication, Control and Information Technology (C3IT)

et al. 2015

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 abovementioned three doping profiles of Si/3C-SiC MQW heterostructure 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 Bohm Potential are incorporated to provide a quantum equivalent of driftdiffusion 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. Keywords-Multiple quantum wells; Si/3C-SiC heterostructures; DDR IMPATTs; millimeter-wave.I.

“…The intrinsic avalanche noise in IMPATT device depends mainly on the carrier ionization rates in the base semiconductor material [5]. The group IV-IV compound semiconductor, Si 1− Ge has been used as an important base material for both optoelectronic and microelectronic devices [6][7][8][9]. Si 1− Ge is a bandgap engineered material whose material properties depend on the Ge mole fraction ( ) [10].…”

Section: Introductionmentioning

confidence: 99%

Noise Performance of Heterojunction DDR MITATT Devices Based on at W-Band

Acharyya

Active and Passive Electronic Components

2013

Self Cite

Noise performance of different structures of anisotype heterojunction double-drift region (DDR) mixed tunneling and avalanche transit time (MITATT) devices has been studied. The devices are designed for operation at millimeter-wave W-band frequencies. A simulation model has been developed to study the noise spectral density and noise measure of the device. Two different mole fractions and of Ge and corresponding four types of device structure are considered for the simulation. The results show that the -Si heterojunction DDR structure of MITATT device excels all other structures as regards noise spectral density ( sec) and noise measure (33.09 dB) as well as millimeter-wave properties such as DC-to-RF conversion efficiency (20.15%) and CW power output (773.29 mW).