Impurity Profiles within a Shallow p-n Junction by a New Differential Spreading Resistance Method

A new simple model for profil ing the impurit ies within a shal low p-n junc-tion from spreading resistance data is proposed. Dickey's capacitance analogue method is extended to a "mult i layer " geometry. Direct translat ion of the differential sheet conductance method to the spreading resistance method is performed. As examples of this approach, the cases of shallow boron (11B+)-, phosphorus (~lp+)., and arsenic (As)-doped layers in silicon are discussed. Mechanical or technical problems involved in obtain-ing rel iable spreading resistance data have been almost completely settled and automatic measuring equipment is commercial ly available. 1 However, the procedure for determining impur i ty profiles from spreading resist-ance data is sti l l worthy of improvement. Many at-tempts have been made to determine accurate correc-tion factors, which must be applied to the measure