Thermal cleaning of air-exposed p-type InGaAs films and CBE regrowth of carbon-doped InGaAs layers for optical device applications

We have studied thermal cleaning of air-exposed Zn-doped InGaAs films and r egrowth of carbon-doped InGaAs layers in terms of carrier concentration pro files and residual oxides. As the cleaning temperature prior to CBE regrowt h is increased, the residual oxides at the regrowth interface exponentially decrease, and the carrier concentration at the interface approaches the in tentional doping level. Elevating the temperature to 575 degrees C provides a "clean" interface, i.e., the carrier profiles are flat. SIMS reveals tha t the carbon atoms doped to 10(20) cm(-3) in the CBE film do not diffuse to the adjacent Zn-doped MOCVD film at all. The thermal cleaning and regrowth procedure was applied to an air-exposed MOCVD film with laser structure fo r the purpose of nonalloy ohmic contact layer. 1.3 mu m-wavelength buried-h eterostructure laser diodes with cleaved facets have a large light output o f more than 20 mW per facet. (C) 1999 Published by Elsevier Science B.V. Al l rights reserved.