Premium
Gettering Mechanism of Copper in n‐Type Silicon Wafers
Author(s) -
Ozaki Rie,
Torigoe Kazuhisa,
Mizuno Taisuke,
Yamamoto Kazuhiro
Publication year - 2019
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201900220
Subject(s) - copper , getter , dopant , materials science , wafer , silicon , impurity , arsenic , doping , antimony , metallurgy , inorganic chemistry , chemistry , optoelectronics , organic chemistry
The dependence of the gettering efficiency for copper impurity in n‐type silicon wafers on the concentration of a dopant such as phosphorus, arsenic, or antimony is investigated by chemical analysis of the copper concentration and the observation of copper precipitates. It is found that the gettering efficiency decreases gradually with increasing dopant concentration in the range of 10 14 –10 19 cm −3 and increases rapidly at concentrations higher than 10 19 cm −3 . Copper precipitates are observed in the bulk of silicon wafers doped with phosphorus in the concentration range of 10 14 –10 19 cm −3 , suggesting that the relaxation gettering of copper occurs. In contrast, no copper precipitates are observed at concentrations above 10 19 cm −3 . It is suggested that segregation gettering occurs as a result of the pairing reaction between copper and heavily doped phosphorus. It is concluded that the gettering mechanism of copper in n‐type silicon wafers changes from relaxation gettering to segregation gettering with increasing dopant concentration.