Gettering of copper impurity in silicon by aluminum precipitates and cavities

Gettering of copper impurity in silicon by aluminum precipitates and cavities 1 first-author 1 1 1 State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, the Chinese Academy of Sciences, Shanghai 200050 State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, the Chinese Academy of Sciences, Shanghai 200050 Al precipitates as well as cavities (or open-volume defects) are known for their ability to getter impurities within Si. In order to compare their relative gettering strength we produced both Al precipitates and cavities at different depths within one Si wafer. This was done by H + and Al + implantation with different energies and subsequent annealing process, resulting in Al-Si alloy and cavities at depth of 300 nm and 800 nm, respectively. Cu was then implanted with an energy of 70 keV to a fluence of 1×10 14 /cm 2 . The Cu implanted samples were annealed at temperature from 700℃ to 1200℃. It was found that Cu impurities were gettered primarily by the precipitated Al layer rather than by cavities at the temperature of 700~1000℃, while gettering of Cu occured in both regions at the temperature of 1200℃. The secondary ion mass spectrometry and transmission electron microscopy analyses were used to reveal the interaction between Cu impurities and defects at different trap sites. Gettering Ion implantation Cavities Al precipitates References Graff K . in Metal impurities in silicon-device fabrication , Springer , New York , 1995 Metal impurities in silicon-device fabrication Mohadjeri B , Williams J S , Wong-Leung J . Appl Phys Lett , 1995 , 66 ( 15 ): 1889 - 1891 Appl Phys Lett Schröter W , Seibt M , Gilles D . in Materials science and technolgy, Vol.4: Electronic structure and properties of semiconductors , edited by Schröter W W , VCH , New York , 1991 , 539 - 589 Materials science and technolgy, Vol.4: Electronic structure and properties of semiconductors Gilles D , Weber E R , Han S K . Phys Rev Lett , 1990 , 64 : 196 Phys Rev Lett Hieslmair H , McHugo S , Weber E R . in Conference record of the 25th IEEE photovoltaic specialists conference-1996 , IEEE , Piscataway, NJ . 1996 , 441 - 444 Spiecker E , Seibt M , Schröter W . Phys Rev B , 1997 , 55 : 9577 Phys Rev B Apel M , Hanke I , Schindler R et al . J Appl Phys , 1994 , 76 : 4432 J Appl Phys Thompson R D , Tu K N . Appl Phys Lett , 1982 , 41 : 440 Appl Phys Lett Verhoef L A , Michiels P P , Roorda S et al . Mater Sci Eng , 1990 , B7 : 49 Mater Sci Eng Wong-Leung J , Ascheron C E . Appl Phys Lett , 1995 , 66 ( 10 ): 1231 - 1233 Appl Phys Lett Myers S M , Follsteadt D M . J Appl Phys , 1996 , 79 ( 3 ): 1337 - 1350 J Appl Phys Raineri V , Battaglia A , Rimini E . Nucl Instr Meth , 1995 , B96 ( 1/2 ): 249 - 252 Nucl Instr Meth Stritzker B , Petravic M , Wong-Leung J et al . Nucl Instr Meth , 2001 , B175-177 : 154 - 158 Nucl Instr Meth O474,TN304.1 + 2,TN305.3 Supported by the National Natural Science Foundation of China (No.69906005) and the Shanghai Youth Foundation (No.01QMH1403) 2002-10-08 2003-08-01 2021-01-19 2003 Nuclear Science and Techniques 03 14