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Titolo:
Structural properties of AlGaN/GaN heterostructures on Si(111) substrates suitable for high-electron mobility transistors
Autore:
Kaiser, S; Jakob, M; Zweck, J; Gebhardt, W; Ambacher, O; Dimitrov, R; Schremer, AT; Smart, JA; Shealy, JR;
Indirizzi:
Univ Regensburg, Inst Expt & Angew Phys, D-93040 Regensburg, Germany Univ Regensburg Regensburg Germany D-93040 , D-93040 Regensburg, Germany Tech Univ Munich, Walter Schottky Inst, D-85748 Garching, Germany Tech Univ Munich Garching Germany D-85748 nst, D-85748 Garching, Germany Cornell Univ, Sch Elect Engn, Ithaca, NY 14850 USA Cornell Univ Ithaca NYUSA 14850 iv, Sch Elect Engn, Ithaca, NY 14850 USA
Titolo Testata:
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
fascicolo: 2, volume: 18, anno: 2000,
pagine: 733 - 740
SICI:
1071-1023(200003/04)18:2<733:SPOAHO>2.0.ZU;2-S
Fonte:
ISI
Lingua:
ENG
Soggetto:
MOLECULAR-BEAM EPITAXY; LIGHT-EMITTING-DIODES; GAN; NITRIDE; SILICON; GROWTH;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Engineering, Computing & Technology
--discip_EC--
Citazioni:
19
Recensione:
Indirizzi per estratti:
Indirizzo: Kaiser, S Univ Regensburg, Inst Expt & Angew Phys, D-93040 Regensburg, Germany Univ Regensburg Regensburg Germany D-93040 Regensburg, Germany
Citazione:
S. Kaiser et al., "Structural properties of AlGaN/GaN heterostructures on Si(111) substrates suitable for high-electron mobility transistors", J VAC SCI B, 18(2), 2000, pp. 733-740

Abstract

Transmission electron microscopy (TEM) investigations of metal organic vapor phase deposition grown AlxGa1 - xN/GaN heterostructures on Si(111) containing an AIN high-temperature buffer layer have been carried out. The structural properties at the interface and in the epilayer as well as the electronic properties suitable for a high electron mobility transistor (HEMT) were analyzed and compared with systems grown on Al2O3(0001). High resolution TEM (HRTEM) at the AlN/Si(111) interface reveals a 1.5-2.7 nm thick amorphous SiNx layer due to the high growth temperature of T-AIN = 1040 degrees C. Therefore, a grain-like GaN/AlN region extending 40-60 nm appears and it is subsequently overgrown with (0001) orientated GaN material because of geometrical selection. The residual strain at the AlN/Si(111) interface is estimated to be epsilon(r) = 0.3+/-0.6% by Fourier filtering of HRTEM images and a moire fringe analysis. This indicates almost complete relaxation of the large mismatch f(AlN/Si)= +23.4% which seems to be supported by the SiNx layer. Weak beam imaging and plan view TEM show typical threading dislocations in the epilayer with a density of 3x10(9) cm(-2) extending along < 0001> which sometimes form grain boundaries. An AlxGa1 - xN/GaN interface roughness of 3 monolayers is estimated and a small AlxGa1 - xN surface roughness of 1.5 nm is obtained by HRTEM and atomic force microscopy investigationswhich correspond to two-dimensional growth. C-V and Hall measurements reveal two-dimensional electron gas at the Al32Ga68N/GaN interface that has a sheet carrier concentration of 4x10(12) cm(-2). The electron mobility of 820cm(2)/Vs measured at room temperature is applicable for a HEMT grown on Si(111). (C) 2000 American Vacuum Society. [S0734-211X(00)06002-9].

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Documento generato il 29/09/20 alle ore 20:21:45