He-plasma assisted epitaxy for highly resistive, optically fast InP-based materials

InP and related quaternaries (InGaAsP) have been grown by conventional gas source molecular beam epitaxy while simultaneously exposing the growth surface to a He plasma stream generated by electron cyclotron resonance. For growth temperatures from 400 to 450 °C, the InP produced by this process displays greatly increased resistivity, as high as 105 Ω cm, compared to growth without plasma where resistivities are typically less than 1 Ω cm. An InGaAsP quaternary, with band-gap wavelength of 1.55 μm, grown with the plasma displays a sharp band edge and fast photoresponse (15 ps).