Mechanism of bias-dependent contrast in scanning-capacitance-microscopy images

Abstract

Development of a metal patterned cantilever for scanning capacitance microscopy and its application to the observation of semiconductor devices

Calibrated Scanning Capacitance Microscopy for Two-Dimensional Carrier Mapping of n-type Implants in p-doped Si-Wafers

“…As we have shown in a previous publication [17], a stable and monotonic dependence of the SCM signal on the doping level is only achieved if the tip bias is adjusted in a way that the sample underneath the tip is in "accumulation". Then, a decreasing SCM signal is obtained with increasing donor concentration in n-type areas at sufficiently high positive bias, whereas in ptype areas, the SCM signal is negligibly small.…”

Scanning Probe Microscopy on Inorganic Thin Films for Solar Cells

“…Hence, the sign of the measured dC/dV signal points to the type of majority carriers in the device, and its magnitude can be interpreted in terms of the carrier concentration [23]. Quantification and analysis of the measured signal requires detailed modeling [19], and is sometimes done by calibrating the SCM signal with similar samples of known carrier concentration [24]. Metals and insulators display zero SCM signals, since their capacitance is not voltage dependent, and are thus difficult to distinguish by SCM.…”

Study of interface states and oxide quality to avoid contrast reversal in scanning capacitance microscopy

“…Recently, the justification for this deleterious effect was explained, by calculations performed with device simulators, considering a relative shift between the dC/dV -V curves for different doping levels or a sudden degradation of the probe tip during acquisition. 1,3,4 In this work, sample preparation was performed to ensure repeatable measurements and to avoid the contrast reversal SCM imaging on both p-and n-type Si epitaxial staircase structures. The full width at half maximum ͑FWHM͒ value extracted from the dC/dV -V curves is investigated to study the influence of the surface states and to control the oxide layer quality.…”

“…Indeed, it was shown that a compensating dc bias applied to the sample can prevent the contrast reversal effect from occuring. 1,4 This applied dc bias is closely related to the flat band voltage of the C -V curve resulting from the presence, for example, of fixed oxide charges and trapped charges at the SiO 2 /Si interface.…”