Ambient-controlled scanning spreading resistance microscopy (AC-SSRM) profiling study of advanced doping technologies

An ambient-controlled scanning spreading resistance microscopy (AC-SSRM) method and apparatus have been developed for one-dimensional (1D) and two-dimensional (2D) doping profiling measurement. 1D SSRM profiling on blanket (vertical) B-doped Si wafers are conducted to obtain spreading resistance profile SR(x). Modeling is used to convert SR(x) to carrier profile n(x). Replacing the average mobility (μ) with a calibration using μ(x) the carrier (hole) profile n(x) is more accurate. This is especially pronounced near the surface and junction depth (x_j) and is consistent with continuous anodic oxidation technique/differential Hall effect (CAOT/DHE) measured carrier profiles. AC-SSRM method is utilized to evaluate both of the conventional beam-line ion implant and plasma doping (PLAD). The results demonstrate a fair consistence with other doping profiling techniques including electron holography and CAOT/DHE. The results also demonstrate a good correlation with PMOS device electrical performance.