Quantification of Scanning Capacitance Microscopy Imaging of the PN Junction through Electrical Simulation
11 January 1999
Determining the cross-sectional doping profile of very small MOSFETs and specifically the direct measurement of their channel length is necessary for true channel engineering to be possible. The technique of scanning capacitance microscopy (SCM) has generated unprecedented images of the cross-sectional doping profiles of very small transistors. The bias voltage dependence of these images has motivated us to investigate the SCM technique in greater detail. With the aid of electrical simulations, we have focused on the PN junction to establish the qualitative and quantitative relationship between the bias voltage and the PN junction location. The ability to confidently interpret the image produced with SCM will allow us to improve simulation models, trouble-shoot process flow, and determine the effective channel length of semiconductor devices.