AVS 45th International Symposium
    Electronic Materials and Processing Division Thursday Sessions
       Session EM-ThP

Paper EM-ThP5
Heat-Transfer in UHV-Scanning Thermal Microscopy

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Electronic Materials and Processing Poster Session
Presenter: W. Müller-Hirsch, University of Oldenburg, Germany
Authors: W. Müller-Hirsch, University of Oldenburg, Germany
J.P. Parisi, University of Oldenburg, Germany
M.T. Hirsch, University of Oldenburg, Germany
A. Kittel, University of Oldenburg, Germany
L.V. Govor, The State University of Belarus
A.Yu. Olevanov, The State University of Belarus
Correspondent: Click to Email
Scanning thermal microscopy (SThM) offers the capability to map temperature distributions of samples with subµm resolution. A wide variety of microscope configurations and sensor designs have been described in literature. However, most experiments have been performed under ambient conditions and the heat-transfer between sensor and sample was attributed to be mostly due to a liquid film-bridge between sensortip and sample.@footnote 1@ In this study we use a Scanning Thermal Microscope to investigate the heat transfer under ultra-high vacuum (UHV) conditions. A needle-shaped Au/Ni-thermocouple-sensor is brought into close proximity of a liquid nitrogen cooled sample. We find an almost linear increase of the heat-transfer with decreasing tip-sample distance on a length-scale in the range of 10nm. Since our experiments are performed at a base-pressure of 10@super -10@ mbar, the heat conduction path via a liquid film-bridge can be excluded. We discuss other mechansims like electron-, phonon- or photon-coupling between tip and sample as an origin of the heat-transfer in the near-field regime of the sample. Additionally, the observed near-field heat-transfer is sensitive with respect to the sample topography. Measurements of the plateau structure of Au-samples with a homogeneous temperature distribution will be presented and exlained by a simple geometric model. Further measurements investigate the joule-heating of a MIS-diode array with diode-dimensions of 2µm. The inhomogeneous temperature distribution due to the joule-heating of the diodes is clearly resolved in the thermal image of the sample. @FootnoteText@ @footnote 1@K. Lou et.al. J. Vac. Sci. Technol B 15(2) p.349 (1997)