Deep and Shallow Electron Trapping in the Buried Oxide Layer of SIMOX Structures

Abstract

Electrons were injected by UV light into the buried oxide (BOX) layer of pseudo‐separation by implantation of oxygen structures in which the original top Si layer was replaced by a metal electrode. From the photocurrent and metal oxide semiconductor C‐V characteristics, the trapping cross sections, density, and location of the electron traps were determined. Two deep neutral traps with and trapping cross sections are responsible for fixed negative charge formation under electron injection. There are also shallow traps present which are responsible for transient effects with a time constant of about 100 s associated with photocurrents. The cross section of the shallow traps is of the order of 10−11 cm2 indicating that the traps are some inclusions (clusters) rather than network defects in the oxide. Both the deep and shallow traps are in the vicinity of the Si‐substrate/BOX interface.