Solid Phase Epitaxial Regrowth of Implanted III-V Materials and Alloys
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SOLID PHASE EPITAXIAL REGROWTH OF IMPLANTED III-V MATERIALS AND ALLOYS CHRISTIAN LICOPPE, YVES.I. NISSIM, CHRISTELLE MERIADEC, PIERRE HENOC and CECILE D'ANTERROCHES*, C.N.E.T Laboratoire de Bagneux, 92220 Bagneux (France), * C.N.E.T CNS 38243 Meylan (France) ABSTRACT The amorphous-crystalline (with residual defects) transition is studied in several III-V binary semiconductors and a ternary alloy. Regrowth shows the same behaviour in all cases. The growth kinetics are thermally activated and the activation energies have been measured using time resolved reflectivity measurements. Correlation with vacancy migration characteristic energy is discussed. In the particular case of GaAs, high resolution electron micrograph of the growth front are displayed. They show a rough microscopic structures together with larger scale smooth deformations, attributed to diffusion instabilities. INTRODUCTION The recrystallization properties of implanted III-V semiconductors is a very important topic both from fundamental and technological point of view. At low temperatures where the kinetics of the regrowth are slow enough to make it easily observable, previous studies have yielded several results, obtained mainly in the study of implanted GaAs. Recrystallization occurs by solid phase epitaxy (SPE) [1]. Regrown layers include a high density of residual defects, increasing with initial amorphous depth [2]. Characteristic width of the interfacial region also increases with amorphous depth [3]. Regrowth kinetics of GaAs are thermally activated with an activation energy of 1.6 eV [4]. These results have been extended to InP, [5] and references therein. The aim of this work is twofold, first to extend these observations to other III-V materials and alloys and second to introduce the first observations of the growth front in implanted GaAs at an intermediate stage of recrystallization, obtained by high resolution electron microscopy (HREM). SPE KINETICS IN III-V MATERIALS AND ALLOYS In the first part of this work, we will report an extensive study of SPE kinetics in several materials. Samples were semi insulating chrome-doped GaAs wafer, semi insulating iron-doped InP wafers, undoped InAs, GaP, GaSb and InSb wafers. The ternary alloy which we chose to study was InxGaj -As because of its technological importance. It was a 2 micron thick layer MBE deposited on a semi insulating InP substrate with an indium composition of 0.55 and a lattice mismatch of 5.10-3. Table I lists the implantation parameters for these samples, chosen to ensure complete amorphization of the implanted layer and an amorphous thickness allowing easy observation by time-resolved reflectivity (TRR) experiments. The experimental set-up has been extensively described in previous work [3], [4].
Mat. Res. Soc. Symp. Proc. Vol. 74. 1987 Materials Research Society
386
Material Implanted ion Energy tnev) Dose (x 1014 at/cm2)
GaAs
InP
GaP
GaSb
As
As
D
130
80
100
4
4
8
InAs
In 0 . 55 Gao.
As
As
100
190 100 40
190 100 40
10
8
Si
4 5As
8 2 1.3
Table 1 IMP
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