Modeling of transient point defect dynamics in Czochralski silicon crystals

• Published in: Journal of crystal growth Vol. 230; no. 1; pp. 291 - 299
• Main Authors: Dornberger, E., von Ammon, W., Virbulis, J., Hanna, B., Sinno, T.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2001; Elsevier
• Subjects: A1. Defects; A1. Diffusion; A1. Heat transfer; A1. Point defects; A2. Czochralski method; B2. Semiconducting silicon; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defects and impurities in crystals; microstructure; Exact sciences and technology; Growth from melts; zone melting and refining; Materials science; Methods of crystal growth; physics of crystal growth; Physics; Point defects (vacancies, interstitials, color centers, etc.) and defect clusters; Structure of solids and liquids; crystallography; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; A1. Heat transfer; A2. Czochralski method; A1. Point defects; A1. Diffusion; A1. Defects; B2. Semiconducting silicon; Point defects; Vacancies; Semiconductor materials; Crystal defect density; Interstitials; Theoretical study; Operating mode; Unsteady state; Czochralski method; Computerized simulation; Finite element method; Nonmetals; Silicon; Defect formation; Crystal growth from melts; Concentration distribution
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(01)01319-7

Intrinsic point defects control the formation of grown-in defects in silicon crystals. Under steady state conditions, the type of the prevailing point defect species is exclusively determined by the ratio of pull rate and temperature gradient in the crystal at the interface. In this study, simulations have been performed for transient growing processes where the pulling rate has been abruptly changed. Large reservoirs of interstitials are formed in fast-grown, vacancy-rich crystals near the interface after abruptly reducing the pulling rate for 30 min. During further growth at high pull rate, these interstitial reservoirs are transformed into large ellipsoidal defect patterns. Experimental results are excellently reproduced if equilibrium concentrations are used as boundary conditions for interstitials and vacancies at all crystal surfaces.