PHOTO COLLECTION, MULTIPLICATION, AND DEPLETION LAYER BEHAVIOR IN RETROGRADED PN JUNCTION STRUCTURES
Abstract
Depletion layer, multiplication and photo-collection properties of reversed biased exponentially retrograded p-n junctions are investigated. An analysis of avalanche breakdown in exponentially retrograded p-n junctions results in simple criteria for avoiding breakdown in such structures. Breakdown voltages are extremely dependent on the surface concentration of the retrograded region. The effect of background resistivity on breakdown is also analyzed. Unusual saturation effects in the multiplication versus voltage curve of retrograded p-n diodes are predicted theoretically. Experimental results point toward a confirmation of this theory. The large retarding field in an exponentially retrograded photodiode significantly reduces the basegenerated photo-current at low reverse bias voltages. Increasing the reverse voltage on the diode reduces the length over which this retarding field is effective, thereby increasing the photo transmission coefficient of the diode. From avalanche breakdown considerations, the largest ratio of change due to this effect is only a function of the resistivity and bulk lifetime in the base of the diode. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1962
- Accession Number
- AD0283693
Entities
People
- Harvey C. Nathanson
Organizations
- Carnegie Institute of Technology