K. Takemura et al., RUO2 TIN-BASED STORAGE ELECTRODES FOR (BA,SR)TIO3 DYNAMIC RANDOM-ACCESS MEMORY CAPACITORS/, JPN J A P 1, 34(9B), 1995, pp. 5224-5229
Sputtered (Ba, Sr)TiO3 (BST) thin film capacitors have been fabricated
with thick RuO2/TiN-based storage electrodes and poly-Si contact plug
s, and the electrical properties of the storage electrodes have been s
tudied, The electrode height was higher than 450 nm and the contact si
ze was 0.8 x 0.8 mu m(2). Resistance of the storage electrodes includi
ng contact plugs can be evaluated from the dispersion observed in capa
citance-frequency measurements. TiN oxidation at the RuO2/TiN interfac
e and native oxide at the TiN/Si contact contribute to the electrode r
esistance of RuO2/TiN electrodes. With increasing BST deposition tempe
rature, the thickness of oxidized TIN in RuO2/TiN electrodes increases
and the electrode resistance increases correspondingly. A Bu layer in
serted at the RuO2/TiN interface, a TiN/TiSi2/Si junction and rapid th
ermal annealing in N-2 ambient of the TiN layer are eff effective ways
to reduce the resistance of RuO2/TiN-based electrodes.