Characterization of zirconium silicate gate dielectrics deposited on si(100) using Zr(NEt2)(4) and Si((OBu)-Bu-n)(4)

Abstract

Zirconium silicate [(ZrO2)(X)(SiO2)(1-X)] films were deposited by using a combination of precursors: tetrakis(diethylamido)zirconium [Zr(NEt2)(4)] and tetra-n-butyl orthosilicate [Si(O"Bu)(4)]. An atomically flat interface of silicate/silicon was observed with no interfacial silicon oxide layers and impurity concentrations were less than 0.1 atom % (below detection limits). Zirconium silicate films with similar to20% ZrO2 were amorphous up to 800degreesC and, above 900degreesC, phase separation of the films occurred into crystal ZrO2 and amorphous phases. Dielectric constant (k) of the Zr-silicate films was about 7.3. Hysteresis in capacitance-voltage (C-V) measurements was less than 0.02 V. The leakage current density was 1.63x10(-4) A/cm(2) at a bias of 1.0 V. (C) 2004 The Electrochemical Society.