Effect of point defect injection on diffusion of boron in silicon and silicon-germanium in the presence of carbon
Karunaratne, M.S.A., Willoughby, A.F., Bonar, J.M., Zhang, J. and Ashburn, P. (2005) Effect of point defect injection on diffusion of boron in silicon and silicon-germanium in the presence of carbon. Journal of Applied Physics, 97, (11), 113531.
Boron diffusion in Si and strained SiGe with and without C was studied using point defect injection.Interstitial-, vacancy- and noninjection conditions were achieved by annealing Si capping layers which were either bare, with Si3N4 film or with Si3N4+SiO2 bilayers, respectively. Concentration profiles of B, Ge, and C were obtained using secondary-ion-mass spectrometry and diffusion coefficients of B in each type of matrix were extracted by computer simulation. Under inert annealing, we find that C strongly suppresses B diffusion in SiGe:C, but the effect of C is less strong in Si:C, particularly at high temperatures. In contrast, C only weakly suppresses B diffusion in both Si:C and SiGe:C under interstitial injection. For inert anneal conditions, C reduces the B diffusion coefficient in Si:C by factors of 4.2, 5.9, and 1.9 at 940, 1000, and 1050 °C respectively, whereas for interstitial injection the factors are 2.1, 1.3, and 1.1, respectively. The equivalent factors for SiGe:C are 8.4, 5.9, and 8.0 for inert anneal conditions and 2.2, 3.4, and 1.6 for interstitial injection conditions. The degree of B diffusion suppression achieved in both Si:C and SiGe:C is dependent on the level of C retained during annealing. Diffusion of C is shown to be faster in Si:C and hence less C is retained there after annealing than in SiGe:C. Interstitial injection is shown to strongly enhance C diffusion in both Si:C and SiGe:C and hence decreases the effectiveness of C for B diffusion suppression. These findings illustrate that the retarding effect of C on B diffusion in both Si:C and SiGe:C is strongly reduced when the anneal is carried out under conditions where interstitials are injected from the surface.
|Keywords:||Diffusion, carbon, Si:C, SiGe:C, point defects, boron|
|Divisions:||Faculty of Physical Sciences and Engineering > Electronics and Computer Science > NANO
|Date Deposited:||12 May 2005|
|Last Modified:||07 Mar 2012 16:16|
|Contributors:||Karunaratne, M.S.A. (Author)
Willoughby, A.F. (Author)
Bonar, J.M. (Author)
Zhang, J. (Author)
Ashburn, P. (Author)
|Further Information:||Google Scholar|
|ISI Citation Count:||3|
|RDF:||RDF+N-Triples, RDF+N3, RDF+XML, Browse.|
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