INVESTIGATION OF SEMICONDUCTOR SCHOTTKY BARRIERS FOR OPTICAL DETECTION AND CATHODIC EMISSION,
Abstract
The photoemissive yield of holes from Au into p-type Si obeys the Fowler relationship from threshold (h nu o = 0.28 eV) up to about 0.46 eV where the yield is 0.8% at 77K for an unmatched diode with a Au pad 0.016 in. in diameter. At higher photon energies, the yields are less than the Fowler values. The yield is 4.3% at 1.0 eV. The yield is smaller for larger diameter Au pads. The photoemissive yield per unit area is 10- to 20-fold greater at the edge than in the central region of Au contacts to n-type Si, as determined by scanning with a 0.001 in. light spot. Varying the rate and duration of Au evaporation or heat treating n-type diodes up to 400C have only minor influences on yield. Surface processing of p-type Ge has been developed for fabricating Au contacts. The thickness of the residual film on the etch-polished surface is about 13A. An efficiency of .000062 was measured for cathodic emission from a cesiated Ag-ZnSe diode. Because of large excess currents, this value may be several orders of magnitude less than can be realized. A practical Ag-ZnS vehicle has been developed. The voltage-current characteristics of Ag contacts to ZnSe and ZnS degrade during the heat treatment required for vacuum bake-out. A similar degradation probably occurs for Ni contacts, but not for Pt contacts. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1968
- Accession Number
- AD0678162
Entities
People
- Jerome Cohen
- Jueri Vilms
- Robert J. Archer