SCANNING CAPACITANCE MICROSCOPY MEASUREMENTS AND MODELING - PROGRESS TOWARDS DOPANT PROFILING OF SILICON

A Scanning capacitance microscope (SCM) has been implemented by interf acing a commercial contact-mode atomic force microscope with a high-se nsitivity capacitance sensor. The SCM has promise as a next-generation dopant-profiling technique because the measurement is inherently two dimensional, has a potential spatial resolution limited by tip diamete r of at least 20 nm, and requires no current carrying metal-semiconduc tor contact. Differential capacitance images have been made with the S CM of a variety of bulk-doped samples and in the vicinity of pn juncti ons and homojunctions. Also, a computer code has been written that can numerically solve Poisson's equation for a model SCM geometry by usin g the method of collocation of Gaussian points. Measured data and mode l output for similar structures are presented. How data and model outp ut can be combined to achieve an experimental determination of dopant profile is discussed.