Four‐Point Sheet Resistance Measurements of Semiconductor Doping Uniformity

A system is described for automatically measuring the sheet resistance of doped semiconductor wafers using either a conventional four‐point probe or microelectronic van der Pauw resistors. Graphic display formats useful for conveying information about doping uniformity are discussed, and the tendency of random measurement error to degrade equivalue contour maps is illustrated. Excellent agreement is observed for sheet resistance data obtained from van der Pauw resistors which differ in area by more than three orders of magnitude. It is shown experimentally that the four‐point probe and van der Pauw resistors may be used interchangeably for doping uniformity measurements.