CONTROL OF THE SATURATION VALUE OF PLANAR SI DOPING IN ALLNAS LAYERS GROWN BY METALORGANIC CHEMICAL-VAPOR DEPOSITION

We observed a strong correlation between sheet carrier concentration i n Si planar-doped AlInAs layers and the flow rate of AsH3 supplied dur ing the doping rhe AlInAs layers were grown by metalorganic chemical v apor deposition and were planar doped by supplying Si2H6 in AsH3 atmos phere. The sheet carrier concentration measured by the van der Pauw me thod and the sheet Si atom concentration measured by secondary ion mas s spectrometry agreed well. Our results can be interpreted on the basi c of a previously introduced model taking into account Si incorporatio n and desorption. We applied this desorption effect to doping control in Si planar-doped AlInAs/GaInAs selectively doped heterostructures. B y changing AsH3 flow rate at a given doping time and Si2H6 flow rate, we could control the sheet Si atom concentration and hence the two-dim ensional electron gas in the selectively doped heterostructures.