CAPACITANCE-VOLTAGE MEASUREMENT AND MODELING ON A NANOMETER-SCALE BY SCANNING C-V MICROSCOPY

Presently, a nanometer scale capacitance-voltage (C-V) method for the quantitative measurement of the lateral dopant distribution near a semiconductor surface is being established. An atomic force microscope is used to position a nanometer scale tip at a semiconductor surface, and local C-V measurements are performed. Experimental C-V curves have been performed with tips of sub-50 nm radius on a series of silicon wafers of known dopant density. It is shown that repeatable C-V measurements can be performed with nanometer scale tips, and that the capacitance change from accumulation to depletion varies monotonically with local dopant density. The C-V measurements are compared with the theoretical predictions of a simple analytical model. The experimental measurements will be described and the results will be discussed.