PULSED-LASER DEPOSITION AS A MATERIALS RESEARCH TOOL

Pulsed laser deposition (PLD) is currently being used to deposit a var iety of multicomponent electronic ceramic thin films as a materials re search tool for the development of next generation electronic devices. Examples include YBa2Cu3O7-delta/ferromagnetic multilayers, ferroelec trics and rare earth doped manganite thin films. In YBa2Cu3O7-delta/fe rromagnetic multilayers, the injection of spin-polarized electrons fro m the ferromagnetic material into the superconductor produces a local reduction in the superconducting order parameter. This effect is being used to develop MTS-based digital logic. The electric field effect in SrxBa(1-x)TiO3 thin films is being used to develop tunable microwave circuits. A 4:1 change in the dielectric constant has been observed fo r fields less than or equal to 80 kV/cm. Microstructural defects assoc iated with cation and anion vacancies have been observed in SrxBa(1-x) TiO3 films. These defects have been correlated with dielectric loss an d can be reduced by the use of a compensated targets and a post-deposi tion anneal of the deposited films. A large temperature coefficient of resistance (TCR) has been observed in rare earth doped manganite thin films. A TCR as large as similar to 30% has been observed for well an nealed La0.67Ca0.33MnOdelta thin films. These materials can be used to increase the sensitivity of uncooled IR focal plane arrays by more th an an order of magnitude making them comparable to HgCdTe detectors. T his paper presents the advances in thin film processing and the import ance of PLD as a tool for research in the physics of thin films, mater ials science and the fabrication of devices based on electronic cerami cs. (C) 1998 Elsevier Science B.V.