TY - GEN
T1 - Formation and characterization of multi-layered nanocavities in silicon with cascade helium implantation/anneal
AU - Rangan, S.
AU - Ashok, S.
AU - Chen, G.
AU - Theodore, D.
N1 - Publisher Copyright:
© 2001 IEEE.
PY - 2001
Y1 - 2001
N2 - Nanocavities in Si formed by He ion implantation anneal are of interest for impurity gettering in Si technology, localized lifetime control in power devices, and in layer splitting techniques used in water bonding. We have found that sequential thermal anneal is essential to obtain multiple cavity layers with cascade He implants (40-160 keV, 2×1015-4×1016 cm-2). This behavior is related to the vacancy generation process necessary for cavity formation. Transmission electron microscopy data reveal that, under isothermal anneal, the cavity shape changes from a distinct, aligned hexagonal geometry to a rounded spheroidal shape with increasing anneal time. Photoluminescence (PL) spectra at 77 K reveal a peak at 0.8 eV for all the He-implanted and annealed samples, attributable to band bending around the cavity interfaces. Deep level transient spectroscopy (DLTS) measurements of the cavity region show broad minority carrier (electron in p-type Si) peaks indicative of the presence of defect clusters. Unusual capacitance-temperature (C-T) characteristics with steps and hysterisis are also seen, reflecting metastable behavior arising from change in structural configuration of the cavity defects.
AB - Nanocavities in Si formed by He ion implantation anneal are of interest for impurity gettering in Si technology, localized lifetime control in power devices, and in layer splitting techniques used in water bonding. We have found that sequential thermal anneal is essential to obtain multiple cavity layers with cascade He implants (40-160 keV, 2×1015-4×1016 cm-2). This behavior is related to the vacancy generation process necessary for cavity formation. Transmission electron microscopy data reveal that, under isothermal anneal, the cavity shape changes from a distinct, aligned hexagonal geometry to a rounded spheroidal shape with increasing anneal time. Photoluminescence (PL) spectra at 77 K reveal a peak at 0.8 eV for all the He-implanted and annealed samples, attributable to band bending around the cavity interfaces. Deep level transient spectroscopy (DLTS) measurements of the cavity region show broad minority carrier (electron in p-type Si) peaks indicative of the presence of defect clusters. Unusual capacitance-temperature (C-T) characteristics with steps and hysterisis are also seen, reflecting metastable behavior arising from change in structural configuration of the cavity defects.
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U2 - 10.1109/ICSICT.2001.982155
DO - 10.1109/ICSICT.2001.982155
M3 - Conference contribution
AN - SCOPUS:84964530072
T3 - 2001 6th International Conference on Solid-State and Integrated Circuit Technology, ICSICT 2001 - Proceedings
SP - 1360
EP - 1365
BT - 2001 6th International Conference on Solid-State and Integrated Circuit Technology, ICSICT 2001 - Proceedings
A2 - Iwai, Hiroshi
A2 - Qu, Xin-Ping
A2 - Li, Bing-Zong
A2 - Ru, Guo-Ping
A2 - Yu, Paul
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 6th International Conference on Solid-State and Integrated Circuit Technology, ICSICT 2001
Y2 - 22 October 2001 through 25 October 2001
ER -