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The effects of Si02 reactive ion etching (RIE) in CHF3 / C2F6 on the surface properties of the underlying Si substrate have been studied by X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) techniques. The observed two major modifications are (i) a -50nm thick silicon layer which contains carbon and fluorine and (ii) 2-3nm thick residue layer composed entirely of carbon, fluorine, oxygen and hydrogen on the silicon surface. The thermal behaviors of attributed peaks for C is, Si 2p, 0 Is and

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Investigation of the impurity-induced layer disordering of GaInP (2 monolayers)/AlInP (2 monolayers) superlattice and multi-quantum-well (MQW) active layer in GaInP/AlInP quantum-well distributed Bragg reflector laser diode and its effect on the band gap was performed using transmission electron microscopy, photoluminescence and secondary ion mass spectrometry (SIMS). The GaInP/AlInP superlattice and MQW active layers were completely disordered by Zn diffusion even at 650°C for 5 min. The band gap of active layer was increased by ΔE=155 meV after Zn diffusion. Segregation of Zn was also observed by SIMS analysis.

Rapid thermal annealing (RTA) has been employed for the electrical activation of shallow n-channel layer by Si+ implantation in the fabrication of GaAs MESFET. To prevent considerable outdiffusion of gallium and arsenic from GaAs substrate during annealing, encapsulating layers such as SiNx and SiNx/SiO2 are deposited. The SiNx/SiO2 double dielectric encapsulant is shown to be more effective to improve the electrical activation. Depending on RTA temperature between 900 and 950°C, the maximum activation efficiency exhibits 77% at the implanted energy of 70 keV and the dose of 5x1012 cm-2 . SIMS analyses show the reduction of the hydrogen contained in the silicon nitride and no outdiffusion of Ga and As during RTA. It also shows the sharp Si-profile after RTA at 950'C, 30 sec. The MESFET fabricated using activation with RTA provides better transconductance than that with furnace-annealed activation.