Pulsed laser deposition of electronic ceramics

Abstract

Pulsed laser deposition (PLD) is a unique physical vapor deposition technique which has gained considerable attention recently in the deposition of high quality, high temperature superconductors. In this technique, a short pulsed laser (<100 ns) is focused onto a target of the material to be deposited. The rapid heating, vaporization and plasma formation at the target surface result in a highly forward directed plume of atomic and gas phase species. Unique to this technique is the stoichiometric evaporation of multicomponent materials, irrespective of the individual constituent vapor pressures. Condensation of the stoichiometric plume onto heated single-crystal substrates results in the formation of single-phase, oriented thin films. Typically, depositions are performed in high pressures of reactive gas ambients. YBa 2Cu 3O 7-δ thin films deposited by PLD have excellent d.c. and high frequency transport properties. For YBa 2Cu 3O 7-δ epitaxial multilayer structures of superconductor/dielectric/superconductor are reported. Microwave devices fabricated from superconducting thin films and multilayer films have demonstrated significant performance improvements over devices fabricated from conventional materials. High quality ferroelectric thin films are also being deposited by PLD. The deposition and electrical characterization of oriented PbZr x Ti 1- x O 3 thin films are reported. PLD is shown as a versatile physical vapor deposition technique and will soon be an important industrial coating technique.