AVS 49th International Symposium
    Nanometer Structures Friday Sessions
       Session NS-FrM

Paper NS-FrM8
Two-Dimensional Dopant Profiling by Novel Scanning Capacitance Force Microscopy

Friday, November 8, 2002, 10:40 am, Room C-207

Session: Novel Surface Nanoprobes
Presenter: K. Kobayashi, Kyoto University, Japan
Authors: K. Kobayashi, Kyoto University, Japan
K. Kimura, Kyoto University, Japan
H. Yamada, Kyoto University, Japan
K. Matsushige, Kyoto University, Japan
Correspondent: Click to Email
We have newly developed scanning capacitance force microscopy (SCFM), which is capable of mapping local differential capacitance (dC/dV) without external capacitance sensors, based on electrical force detection. While an electric field alternating at a fixed frequency (f) is applied between a tip and a sample, an induced electrostatic force (ESF) oscillating at its third harmonic frequency (3f) is detected using a lock-in amplifier (LIA). Because the magnitude of the induced ESF is proportional to the product of the square of the applied electric field and the capacitance of the sample (C) which can be modulated at f by the applied electric field especially in semiconductors, the amplitude and the phase of the induced ESF alternating at (3f) contain information on the differential capacitance (dC/dV) of the sample. SCFM works both in contact mode and dynamic mode. Since the sensitivity of SCFM is inherently high owing to the extremely high force sensitivity in scanning force microscopy (SFM), SCFM can be a high-resolution dopant-profiling technique for semiconducting samples. For demonstration of SCFM, a silicon test sample having several microfabricated patterns of p-type, n-type and heavily-doped n-type regions was imaged. Moreover, we demonstrated that SCFM could be also an important analytical tool for high-resolution characterization of ferroelectric domains in ferroelectric material such as a ferroelectric copolymer thin film.