A plasma etching-induced defect state in electron-irradiated n-type bulk section

Abstract

Defect states induced by radio frequency air plasma etching process in n-type bulk silicon have been studied. Deep level transient spectroscopy shows that a deep center with a small electron capture cross section σtn =1.3×10−20 cm−3 and an energy level at 0.41 eV below the conduction band was induced by plasma treatment of previously electron-irradiated Si samples. The spectral dependence of optical cross sections for this defect level was measured by deep level optical spectroscopy, showing that the defect has a strong electron-phonon coupling with a Franck–Condon shift of about 0.4 eV, and that the defect core is repulsive for electrons. The defect anneals out above 400 K, and is also slightly unstable at room temperature.