Enhanced Diffusion and Formation of Defects During Thermal Oxidation

1980 ◽  
Vol 2 ◽  
Author(s):  
J. Narayan ◽  
J. Fletcher ◽  
B. R. Appleton ◽  
W. H. Christie

ABSTRACTEnhanced diffusion of dopants and the formation of defects during thermal oxidation of silicon has been investigated using electron microscopy, Rutherford backscattering, and secondary ion mass spectrometry techniques. Enhanced diffusion of boron was clearly demonstrated in laser annealed specimens in which secondary defects were not present. In the presence of secondary defects, such as precipitates, enhanced diffusion of boron was not observed. The absence of enhanced diffusion during thermal oxidation was also observed for arsenic in silicon. The mechanisms associated with thermal–oxidation enhanced diffusion are discussed briefly.

1998 ◽  
Vol 527 ◽  
Author(s):  
R. J. Hanrahan ◽  
S. P. Withrow ◽  
M. Puga-Lambers

ABSTRACTClassical diffusion measurements in intermetallic compounds are often complicated by low diffusivities or low solubilities of the elements of interest. Using secondary ion mass spectrometry for measurements over a relatively shallow spatial range may be used to solve the problem of low diffusivity. In order to simultaneously obtain measurements on important impurity elements with low solubilities we have used ion implantation to supersaturate a narrow layer near the surface. Single crystal NiAl was implanted with either 12C or both 56Fe and 12C in order to investigate the measurement of substitutional (Fe) versus interstitial (C) tracer diffusion and the cross effect of both substitutional and interstitial diffusion. When C alone was implanted negligible diffusion was observed over the range of times and temperatures investigated. When both Fe and C were implanted together significantly enhanced diffusion of the C was observed, which is apparently associated with the movement of Fe. This supports one theory of dynamic strain aging in Fe alloyed NiAl.


1996 ◽  
Vol 439 ◽  
Author(s):  
J. S. Williams ◽  
M. Petravic ◽  
M. Conway ◽  
K. T. Short

AbstractSecondary ion mass spectrometry and Rutherford backscattering/channeling analysis have been used to study the segregation of Au at moving Si-SiO2 interfaces during bombardment of Si with 15 keV O- ions. Essentially 100% of the Au is found to segregate at a bombardment temperature of 250°C, whereas only partial segregation occurs for room temperature bombardment. Up to 10 monolayers of Au can be segregated in disordered Si behind an SiO2 layer at 250°C. These results are discussed in terms of ion-assisted migration of Au in disordered Si and extremely low solubilities of Au in SiO2.


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