It is investigated how potential drop sheet resistance measurements of areas formed by laser-assisted doping in crystalline Si wafers are affected by typically occurring experimental factors like sample size, inhomogeneities, surface roughness, or coatings. Measurements are obtained with a collinear four point probe setup and a modified transfer length measurement setup to measure sheet resistances of laser-doped lines. Inhomogeneities in doping depth are observed from scanning electron microscope images and electron beam induced current measurements. It is observed that influences from sample size, inhomogeneities, surface roughness, and coatings can be neglected if certain preconditions are met. Guidelines are given on how to obtain accurate potential drop sheet resistance measurements on laser-doped regions.
References
SEMI Standard MF43-0705, “Test methods for resistivity of semiconductor materials,” available at www.semiviews.org and www.semi.org in June 2011, original edition published by ASTM International as ASTM F43-64T.
SEMI Standard MF81-1105, “Test method for measuring radial resistivity variation on silicon wafers,” available at www.semiviews.org and www.semi.org in June 2011, original edition published by ASTM International as ASTM F81-67T.
SEMI Standard MF84-0312, “Test method for measuring resistivity of silicon wafers with an in-Line four-point probe,” available at www.semiviews.org and www.semi.org in March 2012, original edition published by ASTM International as ASTM F84-67T.
SEMI Standard MF374-0312, “Test method for sheet resistance of silicon epitaxial, diffused, polysilicon, and ion-implanted layers using an in-line four-point probe with the single-configuration procedure,” available at www.semiviews.org and www.semi.org in March 2012, original edition published by ASTM International as ASTM F374-74T.
SEMI Standard MF525-0312, “Test method for measuring resistivity of silicon wafers using a spreading resistance probe,” available at www.semiviews.org and www.semi.org in March 2012, original edition published by ASTM International as ASTM F525-77T.
SEMI Standard MF1529-1110, “Test method for sheet resistance uniformity evaluation by in-line four-point probe with the dual-configuration procedure,” available at www.semiviews.org and www.semi.org in October 2010, original edition published by ASTM International as ASTM F1529-94.
