Dislocation locking by oxygen in silicon: New insights to oxygen diffusion at low temperatures

Conference item

We investigated locking of dislocations by oxygen atoms in Czochralski silicon. Experiments were carried out in the temperature range 350-850degreesC for different annealing times (10 s to 10000 h) and three different oxygen concentrations. It has been observed that the locking of dislocations as a function of annealing time has five well-defined regimes. From the 14 temperature dependence of the unlocking stress of dislocations the binding energy of oxygen to dislocations has been deduced. Experimental results have indicated that at temperatures below 700degreesC an enhanced transport of oxygen to dislocations takes place. Numerical simulations of oxygen transport to dislocations showed that the effective diffusivity of oxygen at lower temperatures is different than "normal" diffusivity and can be several orders of magnitude larger. At lower temperatures the value of effective diffusivity becomes dependent on oxygen concentration and has an activation energy of about 1.5 eV. Possible mechanisms leading to "enhanced" oxygen transport are discussed.

Authors: Senkader, S; Giannattasio, A; Falster, R; Wilshaw, P

• Publication status: Published
• Journal: HIGH PURITY SILICON VII, PROCEEDINGS
• Volume: 2002
• Issue: 20
• Pages: 171-182
• Publication date: 2002-01-01
• Event title: 7th International Symposium on High Purity Silicon held at the 202nd Meeting of the Electrochemical-Society
• ISBN: 156677344X
• Keywords: PRECIPITATION; DIMER