Fabrication of ferroelectric microcapacitors with self-aligned top electrodes by electron-beam-induced patterning process

Ferroelectric Pb(ZrTi)O-3 (PZT) microcapacitors, were fabricated by the modified electron-beam-induced patterning process which we proposed. Electron beam irradiation decreased the thickness of precursor films and made them insoluble in organic solvent. Platinum thin films were deposited on the precursor films with hollows generated by electron beam irradiation. The acceleration. voltage of an electron beam was decreased from 25 to 10 kV in order to form suitable hollows for lift-off. It seems that the scattered electron beam generated sidewalls with a reversed tapered shape. Only the Pt thin films on the unirradiated area were removed with precursor films by development, and self-aligned top electrodes were formed on the top of the remaining ferroelectric micropatterns using the lift-off technique. The 800 x 800 nm(2) PZT microcapacitors were successfully fabricated by this process. The PZT capacitors with sizes larger than 3 x 3 mum(2) exhibited ferroelectric properties, although remanent polarization was lower than that of PZT thin films fabricated by the conventional chemical solution deposition technique.