Comparative Study of Oxygen- and Carbon-Related Defects in Electron Irradiated Cz–Si Doped with Isovalent Impurities

Abstract

Crystalline silicon (Si) is the key material of the semiconductor industry, with significant applications for electronic and microelectronic devices. The properties of Si are affected by impurities and defects introduced into the material either during growth and/or material processing. Oxygen (O) and carbon (C) are the main impurities incorporated into the crystal lattice during growth via the Czochralski method. Both impurities are electrically neutral, however, implantations/irradiations of Si lead to the formation of a variety of oxygen-related and carbon-related defects which introduce deep levels in the forbidden gap, inducing generally detrimental effects. Therefore, to control Si behavior for certain applications, it is important to have an understanding of the properties and fundamental processes related with the presence of these defects. To improve Si, isovalent doping during growth must be employed. Isovalent doping is an important defect-engineering strategy, particularly for radiation defects in Si. In the present review, we mainly focus on the impact of isovalent doping on the properties and behavior of oxygen-related and carbon-related defects in electron-irradiated Si. Recent experimental results from infrared spectroscopy (IR) measurements coupled with theoretical studies involving density functional theory (DFT) calculations, are discussed. Conclusions are reached regarding the role of isovalent doping (carbon, (C), germanium (Ge), tin (Sn), and lead (Pb)) on the suppression of detrimental effects introduced into Si from technologically harmful radiation clusters induced in the course of material processing.

Carbon-Isovalent Dopant Pairs in Silicon: A Density Functional Theory Study

“…Aside from oxygen, carbon is an important impurity in Si unintentionally added during material growth [1,9,15,16]. In previous studies, the interactions of C with selfinterstitials and various impurities have been reported to mainly be with O and other C atoms, leading to families of (C-O)-related (for instance, C i O i , C i O i (Si i ) n ) [9,[16][17][18][19][20] and C-related defects (for instance, C i C s , C i C s (Si i ) n ) [9,16,[21][22][23][24]. Notably, carbon affects oxygen precipitation [25,26] in Si.…”