Μm Thick GaAs Layer Research Articles

Undoped GaAs with a Low Electron Concentration Grown on Si by Mocvd

ABSTRACTWe have successfully grown undoped GaAs of very high resistivity on Si by MOCVD. The back and side edges of the Si substrate were coated with a Si3N4/SiO2 stacked layer to suppress Si incorporation Into GaAs by the gas phase transport mechanism during MOCVD growth. A 3- μm-thick GaAs layer was grown on this Si substrate at 750 °C in an atmospheric MOCVD reactor using the two-step growth technique. The electron concentration measured by a Polaron C-V profiler is 3xl0l4 cm−3, as low as that of GaAs grown on GaAs substrate, up to the depth of 1.5 μm from the surface.

Epitaxial Growth of (100) GaAs on SOS using a Specifically Designed MOCVD System

AbstractHigh quality (100) single domain GaAs layers are epitaxially grown on slightly misoriented (100) Si-on-(1102) sapphire(SOS) substrates by MOCVD. Epitaxial growth on a spherical SOS substrate reveals that R face (1102) should not be tilted toward C axis [0001], but toward [011] or [011] of Si. A new MOCVD system which has two reactors, one for Si cleaning, the other for GaAs deposition, is effective to obtain mirrorlike smooth surface. The X-ray FWHM of 10µm GaAs was reduced to 65 arcsec by the thermal cycle annealing.A crack free 15 µm thick GaAs layer with a dislocation density of 3×106cm-2 is obtained by combining the thermal cycle annealing and the strained-layer superlattices.

High quality heteroepitaxial Ge growth on (100) Si by MBE

An approach to high quality heteroepitaxial Ge growth on Si substrates by MBE has been studied. In the growth method studied here, the Ge layers were grown by a two-step procedure involving a thermal annealing process between the first and second Ge layer growth. It was found that the surface morphology of the Ge depended on the thickness of the first layer, and its thickness of more than 100 nm resulted in smooth surfaces. The crystalline quality of the Ge was affected by both the first and second Ge layer growth temperatures: lowering the growth temperature of the first layer and raising the growth temperature of the second layer in the epitaxial temperature range between 330 and 680°C led to further improvement in crystalline quality. Even further improvement in crystalline quality was accomplished by the high temperature annealing process. Double crystal X-ray diffraction studies showed that the full width at half maximum (FWHM) of the (400) diffraction of the 500 nm thick Ge layer was 240 s. A Ge layer with a dislocation density on the order of 10 7 cm -2 was obtained. A GaAs layer was subsequently grown by MOCVD. The FWHM of the 2 μm thick GaAs layer was 140 s.