Journal of Vacuum Science & Technology B, Vol.24, No.1, 414-420, 2006
Noncontact sheet resistance and leakage current mapping for ultra-shallow junctions
Noncontact measurements of p-n junction photo-voltage give direct measures of sheet resistance and leakage current over the entire range of CMOS doping process. Efficient measurement of leakage current on un-patterned monitor wafers enables the practical use of leakage current as a critical process control parameter for ultra-shallow junction (USJ) fabrication. The impact of sub-junction doping and damage is illustrated by theoretical and experimental investigations for the case of USJ formed in CZ test wafers and halo/well profiles. Correlation to other leakage sensitive measurements, surface band-bending under intense light illumination, and diode I-V characteristics is demonstrated. Comparisons to four point probe measurements for leaky and not-leaky USJ are made. The value of combined monitoring and fast mapping of sheet resistance and leakage current for USJ process is emphasized. (c) 2006 American Vacuum Society.