TUNNELING SPECTROSCOPY IN P-TYPE SILICON.
Abstract
Tunneling in boron doped p-type silicon metal-semiconductor and metal-insulator-semiconductor tunnel junctions has been studied at low temperatures by measuring the derivatives, di/dV and the second derivative of i with respect to V, of the current-voltage characteristics as functions of applied bias voltage V. The junctions were prepared by evaporating metal contacts onto vacuum and air cleaved silicon surfaces. The general features of the tunneling conductance were found to be in qualitative agreement with existing theories of tunneling in semiconductors. Structure in the derivative data resulting from the interaction of tunneling electrons with silicon zone center optical phonons and boron local-mode phonons has been observed. The optical phonon lineshapes in the most heavily doped MIS units are shown to compare well with the theoretical lineshapes in which modifications in the bulk semiconductor states arising from electron-optical phonon interactions in the semiconductor electrode have been included. Anomalous zero-bias conductance minima were observed in the tunneling characteristics of the silicon MS junctions. At least a part of this structure is attributed to intermediate state tunneling whereby electron tunnel from one electrode to the other in two steps via intermediate states localized in the depletion region of the semiconductor. The source of the remaining structure is not known. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1969
- Accession Number
- AD0694304
Entities
People
- Donald Edward Cullen
Organizations
- University of Illinois Urbana–Champaign