# US 2020/0303584 A1 · Method for Producing a Nitrogen-Free Layer Comprising Silicon Carbide > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0303584 A1 - Document ID: US20200303584A1 - Status: Published application - Kind: A1 - Application number: 16/651,384 - Filed: 2018-09-20 - Published: 2020-09-24 - Earliest claimed: 2017-09-27 - Assignees: PSC Technologies, Inc. - Applicants: PSC Technologies GmbH - Inventors: Siegmund GREULICH-WEBER - Web page: https://patentgrep.com/patent/US20200303584A1 ## CPC - H10F 71/121: {The active layers comprising only Group IV materials} - C01B 32/956: Silicon carbide - H10D 62/8325: {Silicon carbide} - H10F 77/122: comprising only Group IV materials - H10P 14/265: {using solutions} - H10P 14/2904: {Silicon carbide} - H10P 14/2922: {being non-crystalline insulating materials, e.g. glass or polymers} - H10P 14/3408: {Silicon carbide} - H10P 95/90: Thermal treatments, e.g. annealing or sintering - Y02E 10/547: Monocrystalline silicon PV cells - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract The present invention relates to a method for producing a thin nitrogen-free layer of silicon carbide by means of a carbon- and silicon-containing solution or dispersion. ## Claims ### Claim at position 1 1-20. (canceled) ### Claim 21 A method for producing a silicon carbide-containing layer, the layer being nitrogen-free, wherein (a) in a first method step, a liquid carbon- and silicon-containing solution or dispersion, in particular a SiC precursorsol, is applied to a carrier, (b) in a second method step following the first method step (a), the carbon- and silicon-containing solution or dispersion, in particular the SiC precursorsol, is converted to silicon carbide, wherein the carbon- and silicon-containing solution or dispersion is subjected to a multi-stage thermal treatment, wherein (i) in a first thermal process stage (i) the carbon- and silicon-containing solution or dispersion, in particular the SiC precursorsol, is heated to temperatures of 300° C. or higher, in particular 300 to 1800° C., preferably 800 to 1000° C., and (ii) in a second thermal process stage following the first thermal process stage (i), the carbon- and silicon-containing solution or dispersion, in particular the SiC precursorsol, is heated to temperatures of 1800° C. or higher, in particular 1800 to 2200° C. ### Claim 22 (depends on 21) Method according to claim 21, characterized in that the thermal process stage (i) is carried out for at least about 5 to 150 minutes, and/or that the thermal process stage (ii) is carried out for at least about 10 to 90 minutes. ### Claim 23 (depends on 21) Method according to claim 21, characterized in that in a process stage preceding the first thermal process stage (i) the carbon- and silicon-containing solution or dispersion, in particular the SiC precursorsol, is heated to temperatures in the range of from 50 to 800° C., for at least substantially 5 to 30 minutes. ### Claim 24 (depends on 21) Method according to claim 21, characterized in that in process stage (i) nitrogen-containing compounds contained in the carbon- and silicon-containing solution or dispersion . . . the SiC precursorsol . . . are decomposed and/or transferred into the gas phase, wherein all nitrogen-containing compounds are decomposed by the temperature treatment, and transferred into the gas phase. ### Claim 25 (depends on 21) Method according to claim 21, characterized in that in process stage (i) the carbon- and silicon-containing solution or dispersion . . . the SiC precursorsol . . . is converted into a glass. ### Claim 26 (depends on 25) Method according to claim 25, characterized in that in process stage (ii) the glass obtained in process stage (i), is converted into crystalline silicon carbide. ### Claim 27 (depends on 21) Method according to claim 21, characterized in that a dopant is added to the SiC precursorsol. ### Claim 28 (depends on 21) Method according to claim 21, characterized in that for the first method step (a), the carbon- and silicon-containing solution or dispersion . . . the SiC precursorsol . . . is applied as a layer, in particular as an homogeneous layer, to a carrier selected from the group consisting of a silicon carbide-comprising carrier, a 3C-SiC-comprising carrier, and an n-doped, carrier. ### Claim 29 (depends on 21) Method according to claim 21, characterized in that in method step (a) the carbon- and silicon-containing solution or dispersion . . . the SiC precursorsol . . . is applied to the carrier by a coating process selected from the group consisting of dip coating, spin coating, spraying, rolling, pressing, and printing. ### Claim 30 (depends on 21) Method according to claim 21, characterized in that in method step (a) the carbon- and silicon-containing solution or dispersion . . . the SiC precursorsol . . . is applied to the carrier as a layer having thickness in the range from 1 μm to 1,000 μm. ### Claim 31 (depends on 21) Method according to claim 21, characterized in that the material of the carrier is selected from the group consisting of carbon, ceramic materials, mineral materials and metals. ### Claim 32 (depends on 31) Method according to claim 31, characterized in that the material of the carrier is selected from the group consisting of graphite, silicon carbide, silicon dioxide, corundum, sapphire, aluminium oxide, steel, and mixtures thereof. ### Claim 33 (depends on 31) Method according to claim 31, characterized in that after the thermal treatment, the carrier is removed. ### Claim 34 (depends on 21) A silicon carbide layer, produced by a method according to claim 21, wherein the silicon carbide layer consists of a silicon carbide layer selected from the group consisting of a SiC layer and a 3C-SiC layer, wherein, the silicon carbide layer or wafer is completely nitrogen-free. ### Claim 35 (depends on 21) Method for producing a solar cell, in particular an intermediate band solar cell having a layered structure with at least one, thin, nitrogen-free layer comprising silicon carbide, produced according to a method according to claim 21 wherein, in order to produce the nitrogen-free layer, (a) in a first method step, a liquid carbon- and silicon-containing solution or dispersion, in particular a SiC precursorsol, is applied to a carrier or a layer of the layered carrier, (b) in a second method step following the first method step (a), the carbon- and silicon-containing solution or dispersion, in particular the SiC precursorsol, is converted to silicon carbide, wherein the carbon- and silicon-containing solution or dispersion, in particular the SiC precursorsol, is subjected to a multi-stage thermal treatment, wherein (i) in a first thermal process stage (i) the carbon- and silicon-containing solution or dispersion, in particular the SiC precursorsol, is heated to temperatures of 300 to 1800° C., and (ii) in a second thermal process stage (ii) following the first thermal process stage (i), the carbon- and silicon-containing solution or dispersion, in particular the SiC precursorsol, is heated to temperatures of 1800 to 2200° C. ### Claim 36 (depends on 35) Method according to claim 35, characterized in that in method step (a) the carbon- and silicon-containing solution or dispersion, (the SiC precursorsol), is applied with a layer thickness in the range from 1 nm to 1,000 μm. ### Claim 37 (depends on 21, 35) Method according to claim 35, characterized in that an at least two-layer structure is applied, wherein the at least two-layer structure has a further layer, comprising silicon carbide, produced according to at least one method feature according to claim 21. ### Claim 38 (depends on 27) Method according to claim 27, characterized in that first the further layer is applied to the carrier and then the nitrogen-free layer is applied to the further layer. ### Claim 39 (depends on 37) Method according to claim 37, characterized in that the further layer is doped, preferably n-doped, in particular by nitrogen and/or phosphorus. ### Claim 40 (depends on 35) An intermediate band solar cell, produced according to claim 35, including a SiC layer or wafer with at least one layer comprising silicon carbide, preferably 3C-SiC, wherein, the at least one layer is completely free of nitrogen.