Effect of strained interfacial layer and large misorientation onSQW, 2DEG, and multisteps in InGaP/(In)GaAs heterostructures grown byMOVPE

摘要

We studied 2DEG performance in Si-doped (including heavilyplanar-doped) InGaP/GaAs heterostructures. We found that Si diffusedfrom InGaP to GaAs, and an In_0.3Ga_0.7P (not GaP)interfacial layer between the Si-doped layer and the channel layer isoptimum for high 2DEG performance. Step bunching due to misorientationis an interesting issue in MOVPE. We studied a misorientation effect andfound that large misorientation over 10° from (001) improves the SQWquality without inserting a GaP layer at the interface. We also foundthat the performance of InGaP-based HEMTs (including inverted-type) isnot linked with the SQW quality, and that misorientation towards<111>A is required for high mobility. We characterized multistepsusing atomic force microscopy (AFM) and concluded that the multistepconfiguration mainly affects abruptness in device structures