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Photoluminescence analysis of C-doped npn AlGaAs/GaAs heterojunction bipolar transistors
Published in G B Stringfellow, Gallium Arsenide and Related Compounds 1991, 2020
Z.H. Lu, M.C. Hanna, E.G. Oh, A. Majerfeld, P.D. Wright, L.W. Yang
Heterojunction bipolar transistors for high-speed devices represent a challenge for both epitaxy and technology. HBT processing requires a large number of highly sophisticated technology steps. A sensitive, destruction free, and quantitative characterization of the total HBT epilayer sequence is very desirable before processing. It has to assure that only high quality wafers enter the time consuming and expensive HBT processing. The epitaxial growth of these HBT layer sequences is complicated both for Metalorganic Vapour Phase Epitaxy (MOVPE) and for Molecular Beam Epitaxy (MBE). Complex n-and p-type doping profiles and material compositions have to be realized. The most difficult task is to grow a very thin ultra-highly doped base with abrupt p+-n−-junctions on both sides. The choice of the acceptor and the epitaxial process have to guarantee that the base doping profile does not change significantly during technology processing of the HBT-wafer, and that it does not degrade during device operation.
In-situ Processing
Published in M S Shur, R A Suris, Compound Semiconductors 1996, 2020
All of the above progress has come from films grown by the metalorganic vapour phase epitaxy (MOVPE) process, whilst much of the fundamental research has been based on films grown by Molecular Beam Epitaxy (MBE). For MBE grown films, the structural and optical properties of the films can be directly related to the growth mechanisms. We have recently demonstrated that growth on GaAs (001) substrates results in ordered polycrystalline columnar material with the [0001] direction in the wurtzite GaN layers being parallel to the [001] direction in the GaAs substrate [6,7]. We have also shown that by supplying an additional As flux to the surface during growth, we can grow single crystal, zinc-blende epitaxial films of GaN on (001) oriented GaAs and GaP substrates.
Analysis of strain and composition distributions in laterally strain-modulated InGaAs nanostructures after overgrowth with GaAs or InGaP
Published in A. G. Cullis, P. A. Midgley, Microscopy of Semiconducting Materials 2003, 2018
U Zeimer, H Kirmse, J Grenzer, S Grigorian, H Kissel, A Knauer, U Pietsch, W Neumann, M Weyers, G Tränkle
The vertical layer structure of the samples was grown in a first epitaxial step by metalorganic vapour phase epitaxy (MOVPE) using the common precursors trimethylgallium, trimethylindium, arsine and phosphine. A 100 nm thick GaAs buffer layer was grown on an exactly oriented (001) GaAs:Si substrate followed by a 10 nm thick In0 . 16Gao. 84As quantum well (QW) with a built-in pseudomorphic strain E = -1.15%. Then a 10 nm thick GaAs layer was deposited serving as a barrier and etch stop layer. Subsequently a 100 nm thick InGaP stressor layer with E = 0.3% was grown followed by a 10 nm GaAs cap layer. The lateral patterning of the GaAs cap layer and the InGaP
60 GHz Source for WLAN Applications Based on IEEE 802.11ad Protocol Standards
Published in IETE Journal of Education, 2019
Prajukta Mukherjee, Aritra Acharyya
The dislocation-free (100)-oriented n+-InP wafer (in case of HMDD and HTDD2) or p+-InP (in case of HTDD1) wafer having the same crystal orientation can be used as the starting raw material for the fabrication of the diodes under consideration. The homo and heterojunction diode structures as shown in Figure 2(a–c) can be formed by growing the required layers on the respective substrate wafers by using low-pressure metalorganic vapour phase epitaxy (LP-MOVPE). Vertical mesa profiles of the diodes can be achieved via reactive ion etching (RIE) technique. Before metallization, the substrate layers of the diodes have to be thinned below the thickness of 10 nm by using backside chemical mechanical polishing (CMP). Finally, the top and bottom electrodes have to be formed by using different standard metallization processes as illustrated in the Figure 2(a–c).