Formation of stacking faults in nitrogen-doped silicon single crystals
The behavior of the ring-like distribution of oxidation-induced stacking faults (OSFs) in nitrogen-doped Czochralski grown single silicon crystals was investigated as a function of the nitrogen and oxygen content. It was found that the inner and outer boundary of the OSF ring is shifted towards the crystal center with higher nitrogen concentration, while, at the same time, the width of the OSF ring increases. This result can be explained by a qualitative model which takes into account the nitrogen-induced change in the temperature-dependent variation of the vacancy concentration. Without nitrogen doping the OSF ring disappears if the oxygen content drops below a critical value. However, the OSF ring reappears at a sufficient nitrogen doping level. The lower the oxygen content, the higher the nitrogen concentration must be to observe an OSF ring. It is shown that this can be understood using the same qualitative model if a critical width of the OSF ring is introduced below which the OSF ring is no longer detectable.
stacking faults nitrogen silicon oxygen vacancy oxygen precipitation