OPTOELECTRONIC INTEGRATED-CIRCUITS GROWN ON SI SUBSTRATES

We have demonstrated the successful fabrication of the monolithic integration of a GaAs metal-semiconductor field-effect transistor (MESFET), an AlGaAs/InGaAs laser and a p-n photodetector grown on a SiO2 backcoated p-Si substrate using selective regrowth by metalorganic chemical vapor deposition (MOCVD). The use Of SiO2 back-coated Si substrate is effective in suppressing unintentional Si autodoping and obtaining a good pinch-off GaAs MESFET. The MESFET with 2.5 x 400 mum2 gate exhibited a transconductance of 90 mS/mm and a threshold voltage of -2.2 V. The reliability of the laser on the Si substrate can be improved by the strain-relieved AlGaAs/InGaAs laser with the InGaAs intermediate layer. The longest lifetime of the laser is 8 h at 27-degrees-C. During the GaAs layer growth, the p-n photodetector is formed near the surface of the p-Si substrate by diffusing the As atoms.