Low-temperature (250 °C) selective epitaxy of GaAs films and p-n junction by laser-assisted metalorganic chemical vapor deposition

Low-temperature selective epitaxial growth of device quality GaAs has been achieved by laser-assisted chemical vapor deposition (LCVD). GaAs substrates thermally biased to temperatures in the range 250–500 °C were irradiated by an Ar ion laser to induce localized deposition of GaAs. Carefully selected growth conditions resulted in growth rates as low as a monolayer per second at 250 °C. This is the lowest substrate temperature for epitaxial GaAs with optical and structural quality comparable to those achieved in conventionally metalorganic chemical vapor deposition grown GaAs. Also reported is the first p-n junction by LCVD technique using zinc as the p-type dopant. This new low-temperature selective deposition process can lead to maskless fabrication of multicomponent devices on the same wafer.