SCANNING CAPACITANCE MICROSCOPY AND SPECTROSCOPY APPLIED TO LOCAL CHARGE MODIFICATIONS AND CHARACTERIZATION OF NITRIDE-OXIDE-SILICON HETEROSTRUCTURES

We have combined a home-built capacitance sensor with a commercial sca nning force microscope to obtain a Scanning Capacitance Microscope (SC M). The SCM has been used to study Nitride-Oxide-Silicon (NOS) heteros tructures which offer potential applications in charge storage technol ogy. Charge writing and reading on a submicrometer scale is demonstrat ed with our SCM setup. In addition, SCM appears to be very useful for the characterization of subsurface defects in semiconductor devices wh ich are inaccessible by most of the other scanning probe microscopies. Finally, we introduce a novel spectroscopic mode of SCM operation whi ch offers combined voltage-dependent and spatially resolved informatio n about inhomogeneous charge distributions in semiconductor devices.