Role of substrates for heteroepitaxial growth of low room-temperature resistivity RuO2 thin films deposited by pulsed laser deposition

Conductive RuO2 thin films were grown on different substrates by pulsed laser deposition. Films deposited on MgO are of (110) orientation and of polycrystalline nature, while highly crystalline RuO2 films can be heteroepitaxially grown on LaAlO3 and yttria-stabilized zirconia (YSZ) substrates under proper processing conditions. The crystalline RuO2 thin films show metallic resistivity versus temperature characteristics and have a room-temperature resistivity of 35+/-2 mu Omega cm. A residual resistivity ratio (rho(300) (K)/rho(4.2 K)) Of around 5 has been achieved for the RuO2 thin films grown at a substrate temperature of 700 degrees C on both LaAlO3 and YSZ. (C) 1996 American Vacuum Society.