TY - JOUR
T1 - Survey of the metal nucleation processes on silicon surfaces in fluoride solutions
T2 - International Symposium on Materials Processing for Nonstruct (MPND2001)
AU - Chemla, Marius
AU - Homma, Takayuki
AU - Bertagna, Valerie
AU - Erre, Rene
AU - Kubo, Nobuhiro
AU - Osaka, Tetsuya
N1 - Funding Information:
This work was supported financially in part by the STMicroelectronics Company, Crolles France, also by the Industrial Technology Research Grant Program from the New Energy and Industrial Technology Development Organization (NEDO), and by a Waseda University Grant for an International Joint Research Project.
PY - 2003/11/15
Y1 - 2003/11/15
N2 - As is well known, contamination of the silicon surface by trace metal impurities is responsible for detrimental effects in the production of ULSI circuits. An extensive experimental study of the factors influencing the spontaneous metal nucleation from fluoride solutions on Si substrates was undertaken. In acidic media (dilute HF solution) only noble metals can be deposited. The mechanism for the formation of Cu element nuclei was chosen as a model example. The first stage was the appearance of Cu crystals of a nanoscopic scale, observed by AFM microscopy. These nuclei soon induce corrosion pits due to the formation of a short-circuited electrochemical cell. In concentrated NH4F solutions, the open circuit potential (ocp) of Si samples is highly negative and provides an efficient driving force for nucleation even for common metals like Fe. Our results show that the deposition of Fe is hardly observable when Fe only is present, but in the presence of Cu, a catalytic effect is observed leading to the co-deposition of Fe+Cu nuclei. In all cases surface defects on the Si substrate are generated by the corrosion pits.
AB - As is well known, contamination of the silicon surface by trace metal impurities is responsible for detrimental effects in the production of ULSI circuits. An extensive experimental study of the factors influencing the spontaneous metal nucleation from fluoride solutions on Si substrates was undertaken. In acidic media (dilute HF solution) only noble metals can be deposited. The mechanism for the formation of Cu element nuclei was chosen as a model example. The first stage was the appearance of Cu crystals of a nanoscopic scale, observed by AFM microscopy. These nuclei soon induce corrosion pits due to the formation of a short-circuited electrochemical cell. In concentrated NH4F solutions, the open circuit potential (ocp) of Si samples is highly negative and provides an efficient driving force for nucleation even for common metals like Fe. Our results show that the deposition of Fe is hardly observable when Fe only is present, but in the presence of Cu, a catalytic effect is observed leading to the co-deposition of Fe+Cu nuclei. In all cases surface defects on the Si substrate are generated by the corrosion pits.
KW - Contamination
KW - Corrosion
KW - Nanoparticles
KW - Semiconductor
KW - Silicon
KW - Surface defects
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U2 - 10.1016/S0022-0728(02)01280-9
DO - 10.1016/S0022-0728(02)01280-9
M3 - Conference article
AN - SCOPUS:0242489286
SN - 0022-0728
VL - 559
SP - 111
EP - 123
JO - Journal of Electroanalytical Chemistry
JF - Journal of Electroanalytical Chemistry
Y2 - 16 September 2001 through 19 September 2001
ER -