Study of the Electronic Surface States of III-V Compounds and Silicon
Abstract
Our work during the past year has progressed in several areas. (1) Si-Metal Contacts: We have investigated a number of transition metals (Ni, Pd, Pt, Ag) on Si to determine both the abruptness of the interface and the nature of the chemical bonding between Si and the metal. We have also examined in some detail the removal of the surface states on a cleaved Si surface by oxygen, cesium, and transition metals. (2) Laser Enhanced Oxidation of GaAs (110): We have demonstrated an increase in the oxygen sticking probability on the GaAs (110) surface by exposure to low-intensity (less than or equal 3w/cm2) laser radiation. We believe this enhancement is due to an increase in the density of free electrons at or near the surface. (3) Oxygen Chemisorption on GaAs (110): New valence band measurements, sensitive to very low (<0.001) monolayer) oxygen coverages, have revealed that the chemisorbed state of oxygen on GaAs (110) consists of an oxygen bonded to a surface As in addition to an oxygen bridging between that As and a next nearest Ga. (4) Interface Between GaAs-Cs, 0, and Vacuum in NEA Photocathodes: We have completed work which gives fundamental insight into the GaAs-Cs-0 interface region and opens new possibilities for reducing the threshold of response (by using 3-5 semiconductor alloys) of negative electron affinity photocathodes, as well as making stable cathodes at lower wavelengths. (5) Interaction of Oxygen with Si (111): We have investigated the oxygen adsorption properties on both Si surface cleaved at room temperature (which exhibits a 2 x 1 reconstruction) and the annealed surface (7 x 7 reconstruction).
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1980
- Accession Number
- ADA115208
Entities
People
- I. Lindau
- William E. Spicer
Organizations
- Stanford University