Carbon ion (C+) irradiation during molecular beam epitaxy (MBE) growth of GaAs/GaAs and in0.53.Ga0.47As/InP layers was carried out using CIBMBE (combined ion beam and molecular beam epitaxy) method as a function of wide acceleration energy (Ea=30 eV-30 keV) at a constant ion beam current density. Judging from the monitored current density and the net hole concentration (INA-ND|) obtained from Hall effect measurements, activation rate as high as 88% was achieved for as-grown GaAs layers by C+ ion irradiation of Ea=~170eV. It was revealed that by annealing at 800°C, a slight enhancement (~ 10%) of INA-ND| is practiced for Ea <~ 130eV but a significant increase of INA-ND| is realized for Ea>~lkeV. IN in0.53Ga0.47As/InP layers with increasing Ea, a type conversion of electric conduction from n to p was found to occur at Ea= ~70~100eV. these observations describe that Ea plays a vital role to determine the location of incorporated electrical and optical active impurities in GaAs and inGaAs. Further for comparison, C+-implanted GaAs layers were prepared by high-energy (400 keV) ion-implantation as a function of substrate temperature (T1=RT-600 °C). For C dose concentration of lxl018cm-3\ the highest activation rate of ~20 % was obtained at T1=~150 °C. This result states that CIBMBE method is a superior doping method in view of activation rate of introduced dopants and the formation of damage-free ion-irradiated layers.

The defect structure of silicon oxynitride films prepared by the ECR Plasma CVD method have been studied by ESR(electron spin resonance) method. The ESR analysis revealed the presence of three paramagnetic defects,that is, Si dangling bonds(g=2.0055 ΔHpp=8 Oe), Si dangling bonds with N atom neighbors(g=2.004, ΔHpp=12 Oe) and E-center(g=2.0016, ΔHpp=4 Oe). These centers strongly depend on the deposition conditions, such as gas flow rate, and microwave powers. The defect density is minimum for the deposition condition of SiON films, under the gas flow O2 /(N2 +02)ratio of 1/3, gas pressure of 8.3x10−4Torr and microwave power of 50OW.

Electrical properties of heavily Be-doped GaAs grown by molecular beam epitaxy were investigated systematically in a wide range of Be-concentration from 1× 1014 up to 2× 1020 cm-3 by using yan der Pauw technique. Probable carrier scattering mechanisms observed in this work are discussed by taking into account the radiative mechanisms of several new photoluminescence emissions previously observed in the band-edge-emission region of the samples. All samples were checked their electrical properties first at room-temperature. Five selected samples out of them were measured from 10° K up to room-temperature. Samples having the carrier concentration from 1014 to 1018 cm3 presented typical semiconductor-like conduction with finite carrier excitation energy. For samples having carrier concentration 7× 1016 cm -3, the conduction mechanism at high temperature region above 30β K was dominated by holes thermally excited into valence band. At low temperature region below 30° K . it was dominated by holes hopping from neutral to ionized acceptors with the assistance of phonons. Hole mobilities of samples having the carrier concentration from 1017 to 1018 cm-3 showed an anomalous behavior in the low temperature region, which suggests the presence of a new type of carrier scattering mechanism. A radiative center denoted by lg-gl observed in this concentration region will be a candidate scattering center to explain these electrical behaviors. Samples having the carrier concentration larger than 1019 cm-3 demonstrated typically metallic electric conduction not owing to thermally excited carriers, which means that an impurity band is formed but merged with valence band. The density of state of this combined valence band mixed with impurity band can be supposed to reflect carrier concentration dependence of the PL emission bands observed in this region, i.e. [g-g]α , [g-g]β and [g-g]γ .

Implantation of Mg+ and C+ ions is carried out in bulk InP substrates using single or several energies up to 400 keV. The net carrier concentration profile at 300K is measured by capacitance-voltage (C-V) method. The ground and excited states binding energies of Mg and C acceptors are determined by low-temperature selective excitation of photoluminescence (PL). Additional sharp exciton-Iike emissions are detected after annealing of the samples. Their intensity is found to decrease with increasing Mg+ or C+ dose. Annealing-induced activation and/or formation of complex defect are the likely candidate mechanisms for the involved defect.