Vibrational modes and electronic properties of nitrogen defects in silicon

Abstract

Nitrogen impurities form complexes with native defects such as vacancies and self-interstitials in silicon which are stable to high temperatures. These complexes can then suppress the formation of large vacancy and self-interstitial clusters. However, there is little known about their properties. We use first-principles densityfunctional theory to the determine the local vibrational modes, electrical levels and stability of a range of nitrogen-interstitial and vacancy complexes. Tentative assignments of the ABC photoluminescence line and the trigonal SL6 EPR center are made to substitutional-nitrogen pair and the substitutional-nitrogen-vacancy complex.

Nitrogen-Doped Silicon: Mechanical, Transport and Electrical Properties

“…The results of ab initio calculations may offer some insight into the structure of the defect found in this thesis. Calculations by Goss et al predict a level at E c -0.50eV due to the N s V defect [17]. It is possible that N s V is responsible for the deep-level observed in this work.…”

“…Numerical simulations generally suggest that the nitrogen atoms in the dimer are strongly bound with an energy of 3.67 to 4.30eV [15][16][17] and that the dimer is practically immobile with an activation energy for diffusion of 2.38 to 2.69eV [18,19]. Experimental data obtained from a SIMS out-diffusion investigation give an activation energy for nitrogen transport as 2.8eV in the 800 to 1200ºC temperature range [20].…”

“…More recent studies suggest that nitrogen results in levels at E c -0.42eV [31], E c -0.5eV [32] and E v + 0.55eV [32], with the level at E c -0.5eV also being found in older work [30]. The electrical activity of nitrogen-related defects has also been investigated theoretically by the use of density-functional theory calculations [17]. In this work, DLTS and the related technique of high-resolution DLTS (HR-DLTS) [33,34] are used to obtain new experimental results on the electrical activity of nitrogen-related defects in silicon.…”

The effect of nitrogen on void formation in Czochralski silicon crystals

“…Upon lowering temperature, K decreases in proportion to exp(ÀE d /kT), where E d is the binding energy of a dimer, for which we adopt a value of 2.9 eV [11]. The first-principle estimates of E d give 3.6 eV [12] or 4.3 eV [13]. These energies are too large to agree with a relatively high value of K(T m ).…”

Ab-Initio Modeling of Point Defects, Impurities and Diffusion in Silicon

“…Jones et al (8) confirmed this conclusion using a combination of spectroscopic and ab-initio investigations. Except for the work of Gali et al (9), who calculated a binding energy of 1.73 eV, all theoretical investigations agree on a rather high binding energy between 3.67 and 4.3 eV (6,(10)(11)(12).…”