Effects of d-doping on barriers effective heights and series resistance of highly doped n-type GaAs/AIAs/GaAs/AlAs/GaAs heterostructures, grown by molecular beam epitaxy (MBE) at 400?°C, have been studied. As it was expected, inclusion of an n+ d-doped layer at each hetero-interface has reduced the barriers heights and series resistance of the structure significantly, while p+ d-doped layers ha...

1) Spot heights at summits have an accuracy of about ±3.3m at all map scales, in agreement with the published figure. 2) Levelled heights from old 6-inch maps can be a few metres below the summit but are unlikely to be more than a few tenths of a metre higher. 3) The accuracy of old and new 1:50k maps is similar, but where heights have changed the old height has a tendency to be too low. 4) Spo...