Growth of high purity InP and fabrication of high sensitivity InP/GaInAs heterojunction phototransistors on silicon by OMVPE

The growth of high-purity InP on Si and the fabrication of high-speed and high-sensitivity InP/GaInAs heterojunction phototransistors using InP grown on Si by organometallic vapor-phase epitaxy (OMVPE) are described. It is shown that high-quality InP can be grown on Si by optimizing the thickness of a GaAs intermediate layer between the InP and Si. A combination of high speed and high sensitivity can be achieved with small-area InP/GaInAs heterojunction phototransistors grown on Si. High-purity InP-on-Si was grown with an electron mobility as high as 4000 cm²/V-s at 300 K and 25000 cm²/V-s at 77 K. The residual concentrations are as low as 6×10¹⁴ cm^-3. The quality of the material is confirmed by the fabrication of InP/GaInAs heterojunction phototransistors (HPTs) with optical gains of 125 A/W, dark currents as low as 300 pA, and bandwidths of 4.4 GHz