Activated-Surface Chemical Vapor Deposition
Abstract
The purpose of this study has been to construct and to achieve operation of a high-resolution, ultra high vacuum scanning tunneling microscope (STM) and to use the instrument to reveal the chemistry and physics of surface modification, etching or deposition that can be induced by the STM current. Typical approaches to the operational requirements of the STM are described: (1) The mechanical structure of the STM must allow a large range of 3-dimensional motion, yet be sufficiently rigid and isolated from external vibrations to provide less than 1 angstrom vibration of the tip-sample gap and lateral position. (2) Piezoelectrics used in STMs normally depolarize below 200 C, thus limiting vacuum bakeout temperatures to around 150 C. A turbomolecular pump combined with ion and titanium sublimation pumps is used to reach 10-10 torr (UHV). (3) Tungsten tips of a few hundred angstroms radius are produced by suspending a wire in an etching solution with the weight or size of the wire hanging below the neck minimized and the current rapidly terminated after the wire breaks.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 25, 1991
- Accession Number
- ADA236083
Entities
People
- Alan Gallagher
Organizations
- Binghamton University