Micro-miniature structures and method of fabrication thereof

• Main Authors: ZAPPE; HANS H, FAN; LONG-SHEN
• Format: Patent
• Language: English
• Published: 15.11.1994
• Edition: 5
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; CINEMATOGRAPHY; 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; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROGRAPHY; GENERATION; HOLOGRAPHY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MATERIALS THEREFOR; METALLURGY; MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICALDEVICES; MICROSTRUCTURAL TECHNOLOGY; ORIGINALS THEREFOR; PERFORMING OPERATIONS; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTUREOR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS; SEMICONDUCTOR DEVICES; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING

In the fabrication of a free-standing miniaturized structure in a range of about 10 to 20 mu m thick, a method based on a sacrificial system includes the steps of selecting a substrate material, depositing on the substrate material a sacrificial layer of material and patterning the sacrificial layer to define a shape. A photoresist layer of material is deposited on the sacrificial layer and patterned by contrast-enhanced photolithography to form a photoresist mold. Upon the mold there is plated a metallic layer of material. The electroplated structure conforms to the resist profile and can have a thickness many times that of conventional polysilicon microstructures. The photoresist mold and the sacrificial layer are thereafter dissolved using etchants to form a free standing metallic structure in a range of about 10 to 20 mu m thick, with vertical to lateral aspect ratios of 9:1 to 10:1 or more.