Accession Number:

ADA248725

Title:

Variable Temperature Scanning Tunneling Microscopy

Descriptive Note:

Final technical rept. 21 Jul 1988-20 Jul 1991

Corporate Author:

ILLINOIS UNIV AT URBANA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING

Personal Author(s):

Report Date:

1991-07-01

Pagination or Media Count:

26.0

Abstract:

Variable temperature STMSTS has been used over the 4.2 K to 400 K temperature range to study CDW formation and spatial variations of the superconducting energy gap in Pb films. Topographic variations of the superconducting energy gap in Pb films show an intriguing transition from superconducting to normal behavior over distances much less than the bulk coherence length. More recently, effort has been focused on the development of a multi-chamber UHV-STM system that will couple a wide range of STMSTS capability with sample and tip preparation and characterization facilities. The first chamber of this system is fully functional and is being used to study and modify semiconductor surfaces. Other chambers will be specialized for STM nanolithography and cryogenic UHV-STM. This system accommodates UHV sample and tip transfer between chambers in addition to independent chamber operation modes. STM modification of H-passivated silicon surfaces has been accomplished using techniques developed by John Dagata at NIST. A unique STM lateral coarse translation system has been developed and used to locate and modify SiMOSFET structures fabricated for this project. Gratings written by STM within the gate region are being evaluated for the creation of finished devices that will exhibit quantum interference effects at higher temperatures than previously observed. Work is also underway to fabricate planar tunnel junction structures that utilize coulomb charging effects to realize logic functions. Scanning Tunneling Microscopy, Scanning Tunneling Spectroscopy, Low Temperature Ultra- high Vacuum STM, Superconductivity, Superconducting Spectroscopy, Semiconductor Nanostructures, STM Nanofabrication, Nanolithography, Coulomb Blockade, Quantum Interference Effects.

Subject Categories:

  • Electricity and Magnetism
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE