In-growth of an electrically active defect in high-purity silicon after proton irradiation

Abstract

Electrically active defects in irradiated 4H-SiC J. Appl. Phys. 95, 4728 (2004); 10.1063/1.1689731Bistable defect in mega-electron-volt proton implanted 4H silicon carbide Defect-related energy levels in the lower half of the band gap of silicon have been studied with transient-capacitance techniques in high-purity, carbon and oxygen lean, plasma-enhanced chemical-vapor deposition grown, n-and p-type silicon layers after 2-MeV proton irradiations at temperatures at or just below room temperature. The in-growth of a distinct line in deep-level transient spectroscopy spectra, corresponding to a level in the band gap at E V þ 0.357 eV where E V is the energy of the valence band edge, takes place for anneal temperatures at around room temperature with an activation energy of 0.95 6 0.08 eV. The line disappears at an anneal temperature of around 450 K. The corresponding defect is demonstrated not to contain boron, carbon, oxygen, or phosphorus. Possible defect candidates are discussed. V C 2013 AIP Publishing LLC.

Electron and Proton Irradiation of Silicon

“…A general inconvenience of DLTS on irradiation-induced levels in the lower half of the band gap, where the di-interstitial associated levels are expected to be according to theory, is that there are several levels related to interstitial C and O, growing in and disappearing at room temperature, rendering an identification of a di-interstitial associated line very difficult unless care is taken to reduce the carbon and oxygen concentrations in the silicon samples. Nylandsted Larsen et al (2013) have recently identified a level at E V +0.357 eV in oxygen and carbon lean FZ p-and n-type silicon irradiated with 2-MeV protons which grows in at room temperature and anneals at $425 K when positively charged and $475 K when neutral. In p-type Si, the defect is only formed as a primary defect, whereas in n-type, it is also formed as a secondary defect.…”