# US 5,349,922 A · Free standing diamond sheet and method and apparatus for making same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,349,922 A - Document ID: US5349922A - Status: Granted - Kind: A - Application number: 08/099,508 - Filed: 1993-07-30 - Granted: 1994-09-27 - Earliest claimed: 1990-06-13 - Assignees: General Electric Company - Inventors: Thomas R. Anthony; James F. Fleischer - Web page: https://patentgrep.com/patent/US5349922A ## CPC - C23C 16/27: Diamond only - C23C 16/01: on temporary substrates, e.g. substrates subsequently removed by etching - C23C 16/0254: {Physical treatment to alter the texture of the surface, e.g. scratching or polishing} - C23C 16/0272: {Deposition of sub-layers, e.g. to promote the adhesion of the main coating} - C23C 16/271: {using hot filaments} - Y10S 117/915: Separating from substrate - Y10T 117/1016: with means for treating single-crystal [e.g., heat treating] - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The bond strength between a diamond and the substrate onto which it is deposited by the chemical vaporization method is decreased to the point where the diamond can be removed from the substrate as a free standing monolithic sheet. The bond strength can be decreased by polishing the substrate, removing corners from the substrate, slow cooling of the substrate after deposition, an intermediate temperature delay in cooling or the application or formation of an intermediate layer between the diamond and the substrate. The free standing sheet of diamond can be used as a laser lens, metallized to form a mirror, or silver soldered to tungsten carbide to form a cutting tool. ## Claims ### Claim 1 An apparatus for making a diamond by the chemical vapor deposition of an intact sheet of diamond onto a substrate wherein the improvement comprises a uniformly smooth diamond receiving surface on the substrate to provide uniform adhesion sufficient to retain the diamond on the substrate during deposition, but weak enough to allow removal of the diamond from the substrate without breakage after deposition. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the improvement further comprises rounded corners on the diamond receiving surface of the substrate. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein the improvement further comprises rounded edges on the diamond receiving surface of the substrate. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein the improvement further comprises the diamond receiving surface of the substrate being free of corners. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein the improvement further comprises the diamond receiving surface being substantially free of recesses, protrusions or sharp edges which would create non uniform adhesion of deposited diamond on the substrate and prevent the removal of an intact sheet of monolithic diamond from the surface of the substrate. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein surface indentations of the diamond receiving surface of the substrate do not exceed 0.3 microns in depth. ### Claim 7 (depends on 1) The apparatus of claim 1 wherein surface protrusions on the substrate do not exceed 0.3 microns in height. ### Claim 8 (depends on 1) The apparatus according to claim 1 wherein the diamond receiving surface of the substrate is free of sharp edges. ### Claim 9 (depends on 1) The apparatus according to claim 1 wherein the substrate is selected from the class consisting of silicon carbide, tungsten carbide and molybdenum. ### Claim 10 (depends on 1) The apparatus according to claim 1 wherein the substrate is molybdenum. ### Claim 11 An apparatus for the chemical vapor deposition of diamond onto a substrate wherein the improvement comprises the substrate being coated with a material which facilitates release of the diamond from the substrate. ### Claim 12 (depends on 11) The apparatus according to claim 11 wherein the substrate is coated with a boron nitride slurry. ### Claim 13 (depends on 11) The apparatus according to claim 11 wherein the substrate is dusted with a powder selected from the class comprising boron nitride, cerium oxide, graphite or iron oxide. ### Claim 14 (depends on 11) The apparatus according to claim 11 wherein the substrate is coated with ferric ferrocyanide. ### Claim 15 (depends on 11) The apparatus according to claim 11 wherein the substrate is coated with boron. ### Claim 16 (depends on 11) The apparatus according to claim 11 wherein the substrate is coated with molybdenum carbide. ### Claim 17 (depends on 11) The apparatus according to claim 11 wherein the substrate is prereacted with carbon or boron to form a surface coating.