Study of Mechanisms for Long Wavelength Schottky-Barrier Infrared Detectors
Abstract
We have studied ballistic electron transport across metal layers and metal/semiconductor interfaces using a scanning tunneling microscope to inject electrons with a controlled energy into a thin metal film, allows measurements (with spatial resolution approaching lnm) of (1) the local Schottky barrier (SB) height, (2) ballistic mean free paths of energetic electrons (or holes), and (3) transmission probability of hot carriers across the metal/semiconductor interface. The attenuation length of hot electrons (1.5 eV above the Fermi level) in PtSi is measured as approximately 4 nm. We also used BEEM to observe the sharp onset of inelastic scattering mechanisms in Au/Si and PtSi. We observe that the derivative BEEM spectrum of Au/Si (001) n-type is rich with features which may correspond to either M/S interface states or to states in the semiconductor bandgap near the interface. We suggest that these interface scattering processes occur also for other M/S systems. Our experimental BEEM studies indicate that hot electron transport is diffusive in the sense that electrons will scatter elastically many times before an inelastic event will occur. We succeeded in constructing a low temperature (liquid nitrogen temperatures) BEEM head and have taken BEEM spectra of PtSi on P-type Si.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1993
- Accession Number
- ADA270538
Entities
People
- L. J. Schowalter
Organizations
- Rensselaer Polytechnic Institute