Yoshihiro Kawarada

Growth of Single Domain GaAs Layer on (100)-Oriented Si Substrate by MOCVD

Single domain GaAs layers with satisfactory morphology were grown on (100)-oriented Si substrates by heat treatment of the substrates at above 900°C and subsecquent two-step growth at low temperatures of 450°C or below and by conventional growth temperatures. The grown GaAs layers showed a high mobility of 5200 cm2V-1s-1 at room temperature with a carrier density of 1×1016 cm-3.

Growth of GaAs on Si by MOVCD

Abstract GaAs layers with a mirror surface were grown on (100)-oriented Si substrate by MOVCD. The combination of thin GaAs layers grown at low temperatures and GaAs/GaAlAs alternating layers at conventional growth temperatures were found to be effective as a buffer layer. The top GaAs layer showed a relatively high PL intensity although the peak shifted to 834 nm due to the tensile stress arising from the difference in thermal expansion coefficient between GaAs and Si. The growth conditions and the construction of the buffer layer to enable the growth of a good GaAs layer were studied.

Growth of high quality GaAs layers on Si substrates by MOCVD

Abstract High quality GaAs layers were grown on Si(100) wafers by heat treatment of the substrates at high temperatures and a subsequent two-step growth sequence at low temperature and then at the conventional growth temperature. The grown layers showed a high quality, i.e., a single domain structure, a mirror-like surface, high electron mobility, fairly high photoluminescence intensity and low etch pit density. Cross-sectional TEM observation showed that most of the misfit dislocations were confined in the narrow region near the GaAs/Si interface. The growth of GaAs on Si substrates with spherical surfaces showed that a small offset angle from (100) was necessary to grow a single domain GaAs layer. FETs and LEDs fabricated on the grown layers showed nearly the same characteristics as those of the devices on GaAs wafers.

Effects of the Substrate Offset Angle on the Growth of GaAs on Si Substrate

In the growth of GaAs on Si, the effects of the offset angle of the substrate and its direction on the epitaxial layer were studied using spherical Si substrates. The growth was carried out by a low pressure MOCVD system. On the grown layer, milky lines were observed along the [010] and the [001] axis of the substrate. Except for the narrow regions along these milky lines, the grown layer showed a mirror-like surface with a single domain structure. The surface morphology and the etch pit density in the single domain GaAs layer were strongly affected by the offset direction as well as the offset angle of the substrate.

Fabrication of GaAs MESFET Ring Oscillator on MOCVD Grown GaAs/Si(100) Substrate

GaAs MESFET ring oscillators were successfully fabricated on silicon substrate. GaAs epitaxial layers were grown directly by MOCVD on Si(100) substrate. A typical transconductance of 200 mS/mm was observed for the FET of 1.0 µm × 10 µm gate. A minimum propagation delay time of 51 ps/gate at a power dissipation of 1.1 mW/gate was observed for an E/D gate ring oscillator with gate length of 1.0 µm.

Growth of vanadium-doped semi-insulating GaAs by MOCVD

Semi-insulating GaAs layers have been grown by MOCVD by vanadium (V) doping with triethoxylvanadyl: VO(OC2H5)3. The resulting resistivity was 108 Ω cm or more at room temperature. The maximum deep level concentration found was more than 1018 cm-3 without surface roughening. Semi-insulating layers were obtained over a wide range of growth conditions and were obtained over a wide range of growth conditions and were relatively stable to high temperature treatment. Furthermore, this dopant did not show a memory effect.