N. Kondo et al., DIRECT GROWTH OF ALGAAS GAAS SINGLE QUANTUM-WELLS ON GAAS SUBSTRATES CLEANED BY ELECTRON-CYCLOTRON-RESONANCE (ECR) HYDROGEN PLASMA/, JPN J A P 2, 33(1B), 1994, pp. 120000091-120000093
Direct growth of AlGaAs/GaAs single quantum wells (SQWs) on GaAs subst
rates without growing buff er layers is carried out by using electron
cyclotron resonance (ECR) hydrogen plasma cleaning. SQW structures are
successively grown by molecular beam expitaxy (MBE) after the cleanin
g process without breaking the vacuum. Photoluminescence shows intense
and narrow spectra, in clear contrast to that of conventional thermal
cleaning. Atomic force microscopy (AFM) and secondary ion mass spectr
oscopy (SIMS) analyses show that surface roughness and interface impur
ity accumulations are significantly reduced as well. A flat and clean
surface obtained by plasma cleaning improves the quality of grown laye
rs.