Measurements of electric potential in GaAs detectors using Kelvin Probe Force Microscopy

The contact potential difference (CPD) and surface voltage drop (SVD) has been investigated on epitaxial detector p
⁺
-n−n
⁺
— structures using Kelvin Probe Force Microscopy (SPFM). The structures were based on undoped n-GaAs layers. The nonuniform distribution of the CPD in n-GaAs layer has been obtained. Applied reverse bias drops on the three regions within n-GaAs layer.