Scanning capacitance microscopy for two-dimensional doping profiling in Si- and InP-based device structures

We report on the application of cross-sectional Scanning Capacitance Micros copy (SCM) for studying two-dimensional doping variations in Si and InP dev ice structures. Different sample preparation methods were evaluated and the response of the SCM signal from various test structures, including epitaxi ally grown layers with n- and p-doping concentrations ranging from 5 x 10(1 4) to 2 x 10(19) cm(-3), were examined under different imaging conditions. The technique was further evaluated by imaging a Si bipolar transistor stru cture and an InP-based buried heterostructure diode laser. We conclude that valuable information can be gained also from complex device structures.