2-DIMENSIONAL DELINEATION OF SEMICONDUCTOR DOPING BY SCANNING RESISTANCE MICROSCOPY

A new technique for the two-dimensional delineation of P-N junctions is presented using a scanning resistance microscope (SRM). The SRM uses a conducting probe to perform localized resistance measurements over a surface. These resistance measurements are used to delineate between regions of different doping type and concentration. Theoretical simulation shows that the SRM is able to delineate between p-type and n-type regions of a surface, and between regions of high and low dopant concentration. By using contact forces of 10(-4) N, the contact area is estimated to be 30 nm. Experiments have shown that this technique can localize a P-N junction with a lateral spacial resolution of less than 35 nm, over dopant concentrations ranging from 10(15) to 10(20) atoms/cm3. In addition, during resistance measurements the SRM is capable of performing simultaneous surface topography measurements.