FORMATION OF PZT THIN FILM

• Main Author: HIRATA KAZUO
• Format: Patent
• Language: English
• Published: 25.04.1995
• Edition: 6
• Subjects: ARTIFICIAL STONE; BASIC ELECTRIC ELEMENTS; CABLES; CEMENTS; CERAMICS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; CONCRETE; CONDUCTORS; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; INORGANIC CHEMISTRY; INSULATORS; LIME, MAGNESIA; METALLURGY; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; REFRACTORIES; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING ORDIELECTRIC PROPERTIES; SLAG; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TREATMENT OF NATURAL STONE

PURPOSE:To attain a good electric characteristic by depositing a PZT thin film on a high-temp. substrate, etching the surface to remove the Pb-excess layer, keeping the film at a high temp. to re-evaporize Pb and eliminating a Pb-excess region from the vicinity of the PZT thin film surface. CONSTITUTION:A Pb-excess PZT sintered target 26 is used, a substrate 25 is heated to 600-650 deg.C, a gaseous mixture of argon and oxygen is introduced to control the pressure to 0.5-4 Pa, a high-frequency power of 150W is applied on the target 26, and a PZT thin film is deposited on the substrate 25. The thin film is then cooled to room temp., a high-frequency bias is impressed on the substrate 25 to etch the PZT thin film, and the surface layer is removed to a depth of at least about 20nm. Otherwise, the PZT thin film is deposited, a shutter 40 is closed, and the substrate is kept at the same temp. for 20min in the same gas atmosphere while continuing discharge. Consequently, Pb is re-evaporized from the film surface, and a Pb-excess layer is not formed.