AVS 50th International Symposium
    Nanometer Structures Thursday Sessions
       Session NS-ThM

Paper NS-ThM3
Imaging Semiconducting Samples by Scanning Capacitance Force Microscopy (SCFM) and Scanning Capacitance Microscopy (SCM)

Thursday, November 6, 2003, 9:00 am, Room 308

Session: Advances in Scanning Probes
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 recently developed scanning capacitance force microscopy (SCFM) based on electrical force detection which is capable of mapping local differential capacitance (dC/dV) without an ultrahigh frequency capacitance sensor. 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) as a differential capacitance (dC/dV) signal is detected by a lock-in technique. 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. In this paper, we investigate the imaging mechanisms of SCFM using a silicon test sample having several microfabricated patterns of p-type, n-type and heavily-doped n-type regions. Image contrast changes depending on the applied bias voltage to the sample and the laser light irradiation were discussed. Conventional scanning capacitance microscopy (SCM) imaging were also performed and the results obtained by both techniques are compared and their advantages and limitations are discussed.