Through comparing the oxygen precipitation in the heavily and lightly phosphorus (P)-doped Czochralski silicon (CZ Si) specimens subjected to the simulated cooling processes of silicon ingot, we researched the influences of heavily P doping on grown-in precipitates by preferential etching and transmission electron microscopy (TEM). It was found that grown-in precipitates were more significant in heavily P-doped CZ Si than in lightly one. Most grown-in precipitates in heavily P-doped CZ Si were generated at (800–600) °C. The significant grown-in oxygen precipitates in the heavily P-doped CZ Si would change the density and morphology of oxygen precipitation. TEM examination revealed that the grown-in precipitates in heavily P-doped CZ Si were amorphous oxygen precipitates composed of tiny precipitates in essential. Although more or less phosphorus may be incorporated in the grown-in precipitates, however, phosphorus cannot be detected so far. We further confirmed that extending annealing at 550 °C produced significant silicon phosphide (SiP) precipitation in heavily P-doped CZ Si. Summarily, enhancement of grown-in oxygen precipitates was attributed to SiP precipitation and high-concentration vacancy, tentatively. Nonetheless, further investigation on the essential of grown-in precipitates in heavily P-doped CZ Si is worthy.
Grown-in precipitates in heavily phosphorus-doped Czochralski silicon
Yuheng Zeng, Xiangyang Ma, Jiahe Chen, Weijie Song, Weiyan Wang, Longfei Gong, Daxi Tian, Deren Yang; Grown-in precipitates in heavily phosphorus-doped Czochralski silicon. J. Appl. Phys. 1 February 2012; 111 (3): 033520. https://doi.org/10.1063/1.3682112
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