TWO-DIMENSIONAL DOPANT PROFILING BY SCANNING CAPACITANCE MICROSCOPY

▪ Abstract The scanning capacitance microscope (SCM) provides a direct method for mapping the dopant distribution in a semiconductor device on a 10 nm scale. This capability is critical for the development, optimization, and understanding of future ULSI processes and devices. The basic elements of the SCM and its application to nanometer scale metal oxide semiconductor (MOS) capacitor measurements are described. Experimental SCM methods are reviewed. Basic measurements show that nanometer scale capacitance-voltage relations are understood. High-quality probe tips and surfaces are critical for obtaining accurate measurements of two-dimensional dopant profiles. Quantitative modeling of SCM measurement is described for converting raw SCM data to dopant density. An inverse modeling method is presented. Direct comparison between secondary ion mass spectroscopy (SIMS) and SCM-measured dopant profiles are made. Quantitative junction measurements and models are discussed and images of small transistors are presented.

[1]  T. Yao,et al.  Nanometer‐scale characterization of SiO2/Si with a scanning capacitance microscope , 1996 .

[2]  S. Rishton,et al.  Scanning capacitance microscopy on a 25 nm scale , 1989 .

[3]  J. Marchiando,et al.  Scanning capacitance microscopy applied to two-dimensional dopant profiling of semiconductors , 1997 .

[4]  J. Marchiando,et al.  Model database for determining dopant profiles from scanning capacitance microscope measurements , 1998 .

[5]  Clayton C. Williams,et al.  Depth dependent carrier density profile by scanning capacitance microscopy , 1997 .

[6]  D. Adderton,et al.  Two-dimensional scanning capacitance microscopy measurements of cross-sectioned very large scale integration test structures , 1996 .

[7]  Calvin F. Quate,et al.  Charge storage in a nitride‐oxide‐silicon medium by scanning capacitance microscopy , 1991 .

[8]  C. C. Williams,et al.  Direct comparison of cross‐sectional scanning capacitance microscope dopant profile and vertical secondary ion‐mass spectroscopy profile , 1996 .

[10]  The effect of doping profile variations upon deep submicrometer MOSFETs , 1995 .

[11]  Joseph J. Kopanski,et al.  Scanning capacitance microscopy measurement of two-dimensional dopant profiles across junctions , 1998 .

[12]  Yoshihiko Suzuki,et al.  Development of a metal patterned cantilever for scanning capacitance microscopy and its application to the observation of semiconductor devices , 1997 .

[13]  Clayton C. Williams,et al.  Quantitative measurement of two-dimensional dopant profile by cross-sectional scanning capacitance microscopy , 1997 .

[14]  Quantitative two‐dimensional dopant profiling of abrupt dopant profiles by cross‐sectional scanning capacitance microscopy , 1996 .

[15]  Vladimir A. Ukraintsev,et al.  Scanning capacitance spectroscopy: An analytical technique for pn-junction delineation in Si devices , 1998 .

[16]  C. C. Williams,et al.  Capacitance–voltage measurement and modeling on a nanometer scale by scanning C–V microscopy , 1994 .

[17]  P. King,et al.  Scanning capacitance microscopy , 1988 .

[18]  J. Kim,et al.  Direct comparison of two-dimensional dopant profiles by scanning capacitance microscopy with TSUPREM4 process simulation , 1998 .

[19]  Ravi Subrahmanyan,et al.  Methods for the measurement of two‐dimensional doping profiles , 1992 .

[20]  B. Streetman.  Solid state electronic devices , 1972 .

[21]  D. Adderton,et al.  Quantitative scanning capacitance microscopy analysis of two-dimensional dopant concentrations at nanoscale dimensions , 1996 .

[22]  Hemantha K. Wickramasinghe,et al.  Lateral dopant profiling with 200 nm resolution by scanning capacitance microscopy , 1989 .

[23]  J. Kim,et al.  Two-step dopant diffusion study performed in two dimensions by scanning capacitance microscopy and TSUPREM IV , 1998 .

[24]  Jeremiah R. Lowney,et al.  Scanning capacitance microscopy measurements and modeling: Progress towards dopant profiling of silicon , 1995 .

[25]  J. McMurray,et al.  Advances in experimental technique for quantitative two-dimensional dopant profiling by scanning capacitance microscopy , 1999 .

[26]  D. J. Thomson,et al.  Two-dimensional imaging of charge carrier profiles using local metal–semiconductor capacitance–voltage measurement , 1998 .