Moisture-induced capacitance-voltage instabilities in mesoporous silica thin films

Thin films of mesoporous silica (MPS) are attractive for low-permittivity interlayer isolation in integrated circuit wiring. Here, we report the mechanisms of moisture-induced capacitance-voltage (C-V) instabilities in MPS films. Upon annealing Al∕MPS∕Si(001)∕Al capacitors between 80 to 200 °C, the...

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Veröffentlicht in:Applied physics letters 2005-12, Vol.87 (25)
Hauptverfasser: Singh, A. P., Victor, P., Ganesan, P. G., Nalamasu, O., Ramanath, G.
Format: Artikel
Sprache:eng
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Zusammenfassung:Thin films of mesoporous silica (MPS) are attractive for low-permittivity interlayer isolation in integrated circuit wiring. Here, we report the mechanisms of moisture-induced capacitance-voltage (C-V) instabilities in MPS films. Upon annealing Al∕MPS∕Si(001)∕Al capacitors between 80 to 200 °C, the flat-band voltage first increases, reaches a maximum, and then decreases. Concurrently, the initially observed deep depletion behavior is replaced by strong inversion. Subsequent air exposure restores the preanneal C-V characteristics. Kinetics analyses reveal two thermally activated processes: Proton generation through fissure of silanol bonds (activation energy Ea1=0.42±0.04eV) and proton-induced depassivation of dangling bond traps (Ea2=0.54±0.05eV) at the MPS∕Si interface. We present an empirical model correlating these processes with the C-V characteristics. Our findings will be important considerations in designing processes for integrating MPS films into microdevices.
ISSN:0003-6951
1077-3118
DOI:10.1063/1.2146052