Carrier Concentration Dependence of Scanning Capacitance Microscopy Signal in the Vicinity of P-N Junctions
Joseph Kopanski, Jay F. Marchiando, Brian G. Rennex
Scanning capacitance microscopy was used to image 1) boron dopant gradients in p-type silicon, and 2) identical boron dopant gradients in n-type silicon. The bias voltage dependence of the apparent p-n junction location in the SCM images was measured. The theoretic al bias voltage dependence of the apparent p-n junction location of the same structures was determined using a two-dimensional, numerical Poisson Equation solver. The simulations confirm that for equally-doped step junctions; the apparent junction coincides with the electrical junction when the bias voltage is midway between the voltage that produces the peak SCM response on the p-type side and the voltage that produces the peak response on the n-type side. This rule is only approximately true for asymmetrically doped junctions. We also specify the extent of the region on the junction high- and low-sides from which valid carrier profiles may be extracted with a simple model.
, Marchiando, J.
and Rennex, B.
Carrier Concentration Dependence of Scanning Capacitance Microscopy Signal in the Vicinity of P-N Junctions, Journal of Vacuum Science and Technology
(Accessed May 29, 2023)