ABSTRACT
Scanning capacitance microscopy (SCM) has proved to be a powerful technique for electrical characterization of semiconductor materials and devices. This technique has the advantage of combining the high spatial resolution of atomic force microscopy and high sensitivity to doping variation. Doping staircase test structures were used to investigate the SCM signal dependence on doping for InP and InGaAs materials. SCM is used to investigate 5, 10, and 20 nm InGaAs/InP quantum wells grown by metalorganic vapour phase epitaxy and sandwiched between Si-doped InP barriers. The spatial extents of the depletion regions are also comparable to those obtained in SCM measurements. The chapter demonstrates that SCM is capable of detecting the electrons accumulated in the quantum wells and that the SCM signal shows a systematic trend for the wells of different width. It shows that at appropriate tip-sample DC biases depletion regions in the barriers adjacent to the wells are clearly resolved.
