Scanning capacitance microscopy two-dimensional carrier profiling for ultra-shallow junction characterization in deep submicron technology

In this paper, we review our recent work to assess scanning capacitance microscopy (SCM) as a quantitative two-dimensional (2D) carrier profiling method on Si. SCM measurements on a wide variety of samples are discussed. In the case of unipolar Si samples (i.e. samples with a unique majority carriers type) the reliability of the method for quantification of the SCM raw data to carrier concentration profiles has been demonstrated. Angle beveling sample preparation allows quantitative carrier profiling with unprecedented depth resolution (1 nm), as demonstrated on specially designed samples containing B-doped Si/Si0.75Ge0.25/Si quantum wells. Applications to the study of the dopant diffusion and electrical activation of low-energy implanted B in submicron areas (0.38 μm) are shown. In the case of bipolar Si samples (i.e. samples containing electrical junctions), the crucial issue of electrical junction position determination both on cross-section and on bevel is addressed. Applications to a cross-sectioned 0.35 μm n–p–n transistor characterization are shown.