Thickness Dependence of Characteristics for(Ba, Sr)TiO_3 Thin Films Prepared by Metalorganic Chemical Vapor Deposition

概要

論文の詳細を見る
(Ba_<0.6> Sr_<0.4>)TiO_3 thin films were prepared by metalorganic chemical vapor deposition(MOCVD)using bisdipvaloylmethanatobarium tetraethylenepentamine adduct(Ba(C_<11>H_<19>O_2)_2(C_8H_<23>N_5)_2), bisdipvaloylmethanatostrontium tetraethylenepentamine adduct(Sr(C_<11>H_<19>O_2)_2(C_8H_<23>N_5)_2), and titanium isopropoxide(Ti(i-OC_3H_7)_4)as starting materials. The thickness dependence of permittivity and other characteristics were investigated for epitaxially grown barium strontium titanate(BST)thin films on Pt(100)/MgO(100)substrates and nonepitaxially grown BST films on Pt(111)/MgO(100)substrates. The epitaxially grown films had a high relative permittivity(1200)at thicknesses greater than 120nm. Permittivity decreased with the film thickness when the thickness was less than 120nm, but remained constant at thicknesses between 50 and 80nm. The nonepitaxially grown films had a relative permittivity of 600 at a thickness greater than 100nm and decreased with decreasing film thickness when the thickness was below 100nm. In this paper, the origin of thickness dependence is discussed in terms of the grain-size effect and the strain effect.
社団法人応用物理学会の論文
2000-09-30