Abstract:
A method is provided for preventing dopant leaching from a doped structural film during fabrication of a microelectromechanical system. A microstructure that includes the doped structural film, sacrificial material, and metallic material is produced with a combination of deposition, patterning, and etching techniques. The sacrificial material is dissolved with a release solution that has a substance destructive to the sacrificial material. This substance also acts as an electrolyte, forming a galvanic cell with the doped structural film and metallic material acting as electrodes. The effects of the galvanic cell are suppressed by including a nonionic detergent mixed in the release solution.
Abstract:
A method of surface treatment in which a surface having a structure formed thereon is treated with a supercritical fluid (4), characterized by adding ammonium hydroxide, an alkanolamine, a fluoroamine, hydrofluoric acid, or the like as a dissolution aid (5) to the supercritical fluid (4). A surface-active substance (6) may be added to the supercritical fluid (4) together with the dissolution aid (5). The surface-active substance (6) may comprise a polar solvent. The method enables residues to be removed without fail by treatment with the supercritical fluid as the only treatment.
Abstract:
A structural body comprising a substrate and a structural layer formed on the substrate through an air gap in which the structural layer functions as a micro movable element is produced by a process comprising a film-deposition step of successively forming a sacrificial layer made of a silicon oxide film and the structural layer on the substrate, an air gap-forming step of removing the sacrificial layer by etching with a treating fluid to form the air gap between the substrate and the structural layer, and a cleaning step. By using a supercritical carbon dioxide fluid containing a fluorine compound, a water-soluble organic solvent and water as the treating fluid, the sacrificial layer is removed in a short period of time with a small amount of the treating fluid without any damage to the structural body.
Abstract:
A method for depositing an anti-adhesion layer onto a surface of micromechanical structures on a substrate. The material or precursor material to be deposited being delivered to the structures in a dissolution and transport medium. A supercritical CO2 fluid is present as the dissolution and transport medium. Deposition of the material or precursor material is brought about by a change in the physical state of the CO2 fluid or by a surface reaction between the surface and the precursor material. The method makes possible subsequent coating of the micromechanical structures in a cavity after encapsulation thereof, the material to be deposited being delivered via access channels or perforation holes.
Abstract:
The present invention provides methods of manufacturing a MEMS assembly. In one embodiment, the method includes mounting a MEMS device, such as a MEMS mirror array, on an assembly substrate, where the MEMS device has a sacrificial layer over components formed therein. The method also includes coupling an assembly lid to the assembly substrate and over the MEMS device to create an interior of the MEMS assembly housing the MEMS device, whereby the coupling maintains an opening to the interior of the MEMS assembly. Furthermore, the method includes removing the sacrificial layer through the opening. A MEMS assembly constructed according to a process of the present invention is also disclosed.
Abstract:
A method for removing sacrificial layers during the process of fabricating micro-mechanical devices with a solution of super-critical carbon dioxide. A mixture of super-critical carbon dioxide with other solvents, co-solvents and surfactants is used during the process to remove sacrificial layers. The disclosed method has many advantages over the prior art, including a reduction of capillary forces that can damage the free-standing micro-mechanical superstructures, an absence of plasma induced damage caused by ashing operations, and a reduction in the use of environmentally sensitive chemicals. Another advantage of the disclosed process is that the swelling of the photoresist layers is minimized. The disclosed method may be used to remove sacrificial layers that were deposited during the process of fabricating micro-mechanical devices. The method is also effective to remove a protective recoat layer that is deposited over a micro-mechanical device after it has been fabricated.
Abstract:
A method is provided for preventing dopant leaching from a doped structural film during fabrication of a microelectromechanical system. A microstructure that includes the doped structural film, sacrificial material, and metallic material is produced with a combination of deposition, patterning, and etching techniques. The sacrificial material is dissolved with a release solution that has a substance destructive to the sacrificial material. This substance also acts as an electrolyte, forming a galvanic cell with the doped structural film and metallic material acting as electrodes. The effects of the galvanic cell are suppressed by including a nonionic detergent mixed in the release solution.
Abstract:
A method comprises depositing an organic material on a substrate; depositing additional material different from the organic material after depositing the organic material; and removing the organic material with a compressed fluid. Also disclosed is a method comprising: providing an organic layer on a substrate; after providing the organic layer, providing one or more layers of a material different than the organic material of the organic layer; removing the organic layer with a compressed fluid; and providing an anti-stiction agent with a compressed fluid to material remaining after removal of the organic layer.
Abstract:
A method of cleaning and treating a device, including those of the micromechanical (10) and semiconductor type. The surface of a device, such as the landing electrode (22) of a digital micromirror device (10), is first cleaned with a supercritical fluid (SCF) in a chamber (50) to remove soluble chemical compounds, and then maintained in the SCF chamber until and during the subsequent passivation step. Passivants including PFDA and PFPE are suitable for the present invention. By maintaining the device in the SCF chamber, and without exposing the device to, for instance, the ambient of a clean room, organic and inorganic contaminants cannot be deposited upon the cleaned surface prior to the passivation step. The present invention derives technical advantages by providing an improved passivated surface that is suited to extend the useful operation life of devices, including those of the micromechanical type, reducing stiction forces between contacting elements such as a mirror and its landing electrode. The present invention is also suitable for cleaning and passivating other surfaces including a surface of semiconductor wafers, and the surface of a hard disk memory drive.
Abstract:
A method is provided for preventing dopant leaching from a doped structural film during fabrication of a microelectromechanical system. A microstructure that includes the doped structural film, sacrificial material, and metallic material is produced with a combination of deposition, patterning, and etching techniques. The sacrificial material is dissolved with a release solution that has a substance destructive to the sacrificial material. This substance also acts as an electrolyte, forming a galvanic cell with the doped structural film and metallic material acting as electrodes. The effects of the galvanic cell are suppressed by including a nonionic detergent mixed in the release solution.