We present a comprehensive, up-to-date compilation of band parameters for the technologically important III–V zinc blende and wurtzite compound semiconductors: GaAs, GaSb, GaP, GaN, AlAs, AlSb, AlP, AlN, InAs, InSb, InP, and InN, along with their ternary and quaternary alloys. Based on a review of the existing literature, complete and consistent parameter sets are given for all materials. Emphasizing the quantities required for band structure calculations, we tabulate the direct and indirect energy gaps, spin-orbit, and crystal-field splittings, alloy bowing parameters, effective masses for electrons, heavy, light, and split-off holes, Luttinger parameters, interband momentum matrix elements, and deformation potentials, including temperature and alloy-composition dependences where available. Heterostructure band offsets are also given, on an absolute scale that allows any material to be aligned relative to any other.

Band parameters for III–V compound semiconductors and their alloys

Carrier concentration profiles of two-dimensional electron gases are investigated in wurtzite, Ga-face AlxGa1−xN/GaN/AlxGa1−xN and N-face GaN/AlxGa1−xN/GaN heterostructures used for the fabrication of field effect transistors. Analysis of the measured electron distributions in heterostructures with AlGaN barrier layers of different Al concentrations (0.15<x<0.5) and thickness between 20 and 65 nm demonstrate the important role of spontaneous and piezoelectric polarization on the carrier confinement at GaN/AlGaN and AlGaN/GaN interfaces. Characterization of the electrical properties of nominally undoped transistor structures reveals the presence of high sheet carrier concentrations, increasing from 6×1012 to 2×1013 cm−2 in the GaN channel with increasing Al-concentration from x=0.15 to 0.31. The observed high sheet carrier concentrations and strong confinement at specific interfaces of the N- and Ga-face pseudomorphic grown heterostructures can be explained as a consequence of interface charges induced by ...

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Two-dimensional electron gases induced by spontaneous and piezoelectric polarization charges in N- and Ga-face AlGaN/GaN heterostructures

Wide bandgap semiconductors are extremely attractive for the gamut of power electronics applications from power conditioning to microwave transmitters for communications and radar. Of the various materials and device technologies, the AlGaN/GaN high-electron mobility transistor seems the most promising. This paper attempts to present the status of the technology and the market with a view of highlighting both the progress and the remaining problems.

AlGaN/GaN HEMTs-an overview of device operation and applications

Materials research plays a vital role in transforming breakthrough scientific ideas into next-generation technology. Similar to the way silicon revolutionized the microelectronics industry, the proper materials can greatly impact the field of plasmonics and metamaterials. Currently, research in plasmonics and metamaterials lacks good material building blocks in order to realize useful devices. Such devices suffer from many drawbacks arising from the undesirable properties of their material building blocks, especially metals. There are many materials, other than conventional metallic components such as gold and silver, that exhibit metallic properties and provide advantages in device performance, design flexibility, fabrication, integration, and tunability. This review explores different material classes for plasmonic and metamaterial applications, such as conventional semiconductors, transparent conducting oxides, perovskite oxides, metal nitrides, silicides, germanides, and 2D materials such as graphene. This review provides a summary of the recent developments in the search for better plasmonic materials and an outlook of further research directions.

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Alternative Plasmonic Materials: Beyond Gold and Silver

The role of extended and point defects, and key impurities such as C, O, and H, on the electrical and optical properties of GaN is reviewed. Recent progress in the development of high reliability contacts, thermal processing, dry and wet etching techniques, implantation doping and isolation, and gate insulator technology is detailed. Finally, the performance of GaN-based electronic and photonic devices such as field effect transistors, UV detectors, laser diodes, and light-emitting diodes is covered, along with the influence of process-induced or grown-in defects and impurities on the device physics.

Gan : processing, defects, and devices

Microelectronic apparatus having protection against high frequency crosstalk radiation, comprising: a planar insulating substrate; an active semiconductor electronic device located over a first region of the insulating substrate; and a doped semiconductor located in a second region of the insulating substrate substantially surrounding the first region. Apparatus further comprising a dissipative conductor overlaying and adjacent to the doped semiconductor. Apparatus additionally comprising metallic test probe contacts making electrical connections with the active semiconductor electronic device. Application of the apparatus to dissipate crosstalk radiation having a center frequency within a range between about 1 gigahertz and about 1,000 gigahertz. Methods for making the apparatus.

Conductive isolation frames for active microelectronic devices, and methods of making such conductive isolation frames

Modeling of quantum devices is still based on the original idea of Landauer that the macroscopic (DC) conductance of electron devices can be related to the (microscopic) transmission coefficient of electrons. In this paper we propose a simple model that captures the role of the particle and displacement currents in quantum electron devices working at THz by substituting the traditional transmission coefficient by a new displacement current coefficient. In particular, our model is used to compute the total current of a Resonant Tunnelling Diode (RTD) device under AC conditions. The new model, based on a time-dependent approach, is firstly shown to reproduce the DC behaviour of the Landauer model. Later on, at input frequencies higher than 500 GHz, large differences between the two models are observed. In particular, unexpected high frequency behavior is observed in simulations with an input signal up to 2 THz.

The accurate predictions of THz quantum currents requires a new displacement current coefficient instead of the traditional transmission one

On-chip antennas with radiation towards the substrate are affected by modest coupling performance to a free-space path. (Hyper-)hemispherical silicon lenses can improve the efficiency of quasi-optical emission and detection even at THz frequencies. This approach requires an alignment accuracy in the $\mu\mathrm{m}$ -scale at THz frequencies. In this contribution, we report on the benefit of hyper-hemispherical silicon lenses in terms of relaxed alignment accuracy needs. We present the impact of alignment on quasi-optical measurements using indium phosphide resonant-tunneling diodes. The main components of the resulting setups are discussed while the effect of alignment is quantitatively evaluated for both, hemispherical and hyper-hemispherical silicon lenses. Moreover, design rules and concepts for a heterointegrated system are derived on consecutive observations.

THz Detectors and Emitters with On-Chip Antenna aligned on Hyper-Hemispherical Silicon Lenses

The present and predicted limits on microwave power performance of undoped AlGaN/GaN HEMTs are presented, based on measured frequency response and drain-source breakdown voltage, both as functions of gate length. The spontaneous and piezoelectric polarization that induce the 2DEG in these HEMTs are covered. Process methods, including Si/sub 3/N/sub 4/ passivation are included. Thermal simulation results are shown for heat dissipation that limits channel temperature to 300/spl deg/C. Microwave cw power density limits of 12.5 W/mm at 10 GHz are predicted for class A operation on thick SiC substrates.

http://ieeexplore.ieee.org/iel5/7236/19520/00902545.pdf

Power limits of polarization-induced AlGaN/GaN HEMT's

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/pssb.202000395

Nils Weimann

Papers

Conductive isolation frames for active microelectronic devices, and methods of making such conductive isolation frames

The accurate predictions of THz quantum currents requires a new displacement current coefficient instead of the traditional transmission one

THz Detectors and Emitters with On-Chip Antenna aligned on Hyper-Hemispherical Silicon Lenses

Power limits of polarization-induced AlGaN/GaN HEMT's

Tunneling-Related Leakage Currents in Coaxial GaAs/InGaP Nanowire Heterojunction Bipolar Transistors