# US 9,439,295 B2 · Electrically insulating elements and electrically conductive elements formed from elements having different oxidation behaviors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,439,295 B2 - Document ID: US9439295B2 - Status: Granted - Kind: B2 - Application number: 13/870,018 - Filed: 2013-04-25 - Published: 2014-10-30 - Granted: 2016-09-06 - Earliest claimed: 2013-04-25 - Assignees: The United States of America as represented by the Secretary of the Army - Applicants: U.S. Army Research Laboratory - Inventors: Nathan S. Lazarus; Christopher D. Meyer; Sarah S. Bedair - Web page: https://patentgrep.com/patent/US9439295B2 ## CPC - H05K 3/22: Secondary treatment of printed circuits {(H05K3/1283 takes precedence; embedding circuits in grooves by pressure H05K3/107)} - B81C 1/00095: {Interconnects} - G01C 25/00: Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass (testing, calibrating or compensating compasses G01C17/38) - H05K 1/165: {incorporating printed inductors} - H05K 2201/0394: Conductor crossing over a hole in the substrate or a gap between two separate substrate parts - H05K 2203/0315: Oxidising metal - Y10T 29/49002: Electrical device making - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - B81C: PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS (making microcapsules or microballoons B01J13/02; processes or apparatus specially adapted for the manufacture or treatment of piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/01) - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Embodiments of the present invention are directed to electrical devices and methods for fabricating electrical devices using an oxidation process. According to one embodiment, a method of forming an electrical device using an oxidation process includes forming a metallic element which is to become an electrically insulating or resistive element in an electrical device; forming an electrically conductive element connected to the metallic element, wherein the metallic element and the electrically conductive element have different oxidation behavior when subjected to the oxidation process; and subjecting the elements forming the electrically insulating or resistive element and the electrically conductive element to the oxidation process. ## Claims ### Claim 1 A method of forming an electro-mechanical device using an oxidation process, the method comprising: forming a metallic element which is to become an electrically insulating or resistive element; forming an electrically conductive element, wherein the metallic element and the electrically conductive element have different oxidation behavior when subjected to the oxidation process; and subjecting the elements forming the electrically insulating or resistive element and the electrically conductive element to the oxidation process, whereby, in the electro-mechanical device formed using the oxidation process, one or both of the electrically insulating or resistive element and the electrically conductive element suspend an element of the electro-mechanical device, at least partially, above and spaced apart from a substrate or at least one other element of the electro-mechanical device, wherein the electrically conductive element provides an electrical pathway to the suspended element, and the electrically insulating or resistive element does not. ### Claim 2 (depends on 1) The method of claim 1, further comprising: subjecting one or both of the metallic element forming the electrically insulating or resistive element and the electrically conductive element to a release step whereby the suspended element becomes free-standing, suspended, or released from the substrate or the at least one other element of the electro-mechanical device. ### Claim 3 (depends on 2) The method of claim 2, wherein the metallic element forming the electrically insulating or resistive element forms a pillar, post, beam, column or flexure structure in the electro-mechanical device. ### Claim 4 (depends on 2) The method of claim 2, wherein the release step comprises: removing a supporting mold, etching of a sacrificial layer, or detachment from the substrate or at least one other element of the electro-mechanical device. ### Claim 5 (depends on 1) The method of claim 1, wherein one or both of the metallic element forming the electrically insulating or resistive element and the electrically conductive element are fabricated as a free-standing or suspended structure without an additional release step. ### Claim 6 (depends on 1) The method of claim 1, wherein the electrically conductive element is metallic. ### Claim 7 (depends on 1) The method of claim 1, wherein the electrically conductive element is a non-metallic conductor. ### Claim 8 (depends on 7) The method of claim 7, wherein the electrically conductive element is polysilicon. ### Claim 9 (depends on 1) The method of claim 1, wherein the metallic element forming the electrically insulating or resistive element is formed of a metal which readily oxidizes during the oxidation process. ### Claim 10 (depends on 9) The method of claim 9, wherein the metal which readily oxidizes during the oxidation process comprises copper, nickel, titanium, zirconium, hafnium, tantalum, or niobium. ### Claim 11 (depends on 9) The method of claim 9, wherein during the oxidation process, the metal is substantially converted to an oxide of the metal. ### Claim 12 (depends on 9) The method of claim 9, wherein during the oxidation process, a portion of the metal is converted to an oxide of the metal and another portion thereof remains substantially the metal. ### Claim 13 (depends on 1) The method of claim 1, wherein the metallic element forming the electrically insulating or resistive element and the electrically conductive element are each formed from a metal which readily oxidizes during the oxidation process. ### Claim 14 (depends on 13) The method of claim 13, wherein the electrically conductive element has a greater thickness or diameter than the metallic element forming the electrically insulating or resistive element. ### Claim 15 (depends on 14) The method of claim 14, wherein during the oxidation process, only a surface layer of the metal of the conductive element is converted to a metal oxide. ### Claim 16 (depends on 1) The method claim 1, wherein the electrically conductive element is formed of a metal which does not readily oxidize during the oxidation process. ### Claim 17 (depends on 16) The method of claim 16, wherein the metal comprises gold, nickel, aluminum, or platinum. ### Claim 18 (depends on 1) The method of claim 1, wherein the oxidation process comprises: a bake at an elevated temperature, exposure to oxygen plasma, or exposure to ozone. ### Claim 19 (depends on 1) The method of claim 1, wherein the electro-mechanical device is configured as an inductor, gyroscope, accelerometer, chemical sensor, pressure sensor, or variable capacitor. ### Claim 20 (depends on 1) The method of claim 1, wherein the metallic element forming the electrically insulating or resistive element and the electrically conductive element are differentiated by coating a surface of the conductive element. ### Claim 21 (depends on 20) The method of claim 20, wherein the surface coating comprises: octadecanethiol or a non-oxidizing metal. ### Claim 22 (depends on 1) The method of claim 1, wherein the metallic element forming the electrically insulating or resistive element, the electrically conductive element, or both, are deposited by electroplating. ### Claim 23 (depends on 1) An electro-mechanical device formed by the method of claim 1 comprising: the electrically insulating or resistive element formed from the metallic element; and the electrically conductive element, whereby one or both of the electrically insulating or resistive element and the electrically conductive element suspend an element of the electro-mechanical device formed by the oxidation process, at least partially, above and spaced apart from the substrate or the at least one other element of the electro-mechanical device, wherein the metallic element and the electrically conductive element have different oxidation behavior when subjected to the oxidation process such that the electrically conductive element provides an electrical pathway to the suspended element, and the electrically insulating or resistive element formed from the metallic element does not. ### Claim 24 (depends on 1) The method of claim 1, wherein the electrically conductive element is connected to the metallic element. ### Claim 25 A method of forming an electrical device using an oxidation process, the method comprising: forming a metallic element which is to become an electrically insulating or resistive element; forming an electrically conductive element, wherein the metallic element and the electrically conductive element have different oxidation behavior when subjected to the oxidation process; and subjecting the elements forming the electrically insulating or resistive element and the electrically conductive element to the oxidation process, whereby, in the electrical device formed using the oxidation process, one or both of the electrically insulating or resistive element and the electrically conductive element suspend an element of the electro-mechanical device, at least partially, above and spaced apart from a substrate or at least one other element of the electrical device, wherein the electrically conductive element provides an electrical pathway to the suspended element, and the electrically insulating or resistive element does not.