# US 12,002,708 B2 · Method for forming intermetallic air gap > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,002,708 B2 - Document ID: US12002708B2 - Status: Granted - Kind: B2 - Application number: 17/613,491 - Filed: 2019-12-04 - Published: 2022-08-04 - Granted: 2024-06-04 - Earliest claimed: 2019-05-23 - Assignees: Shanghai Ic R&D Center Co., Ltd; Shanghai Integrated Circuit Equipment & Materials Industry Innovation Center Co., Ltd - Applicants: Shanghai Ic R&D Center Co., Ltd.; Shanghai Integrated Circuit Equipment & Materials Industry Innovation Center Co., Ltd - Inventors: Xiaoxu Kang; Ruoxi Shen; Xiaolan Zhong - Web page: https://patentgrep.com/patent/US12002708B2 ## CPC - H10P 90/1906: {Preparing SOI wafers} - H10W 20/072: {of dielectric parts comprising air gaps} - H10D 62/115: {Dielectric isolations, e.g. air gaps} - H10P 14/6342: {Liquid deposition, e.g. spin-coating, sol-gel techniques or spray coating} - H10P 14/68: Organic materials, e.g. photoresists - H10W 10/021: {of air gaps} - H10W 10/061: {using SOI processes together with lateral isolation, e.g. combinations of SOI and shallow trench isolations} - H10W 10/181: {Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers} - H10W 10/20: Air gaps - H10W 20/46: comprising air gaps - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract The present invention discloses a method for forming an intermetallic air gap, which comprises following steps: S01: forming a trench in a solid dielectric; S02: preparing an insulating sheet-like two-dimensional material, wherein the insulating sheet-like two-dimensional material comprises an insulating nano sheet-like layer, the size of the insulating nano sheet-like layer in the sheet-like two-dimensional direction is greater than the size of the trench; S03: the insulating sheet-like two-dimensional material is deposited on the solid dielectric and the trench; S04: annealing the solid dielectric and the insulating sheet-like two-dimensional material to form a stable thin film composed of insulating sheet-like two-dimensional material on the trench. The method for forming an intermetallic air gap provided by the present disclosure can effectively increase the intermetallic air gap formation ratio, and greatly reduce the effective dielectric constant and interconnection delay, further reduce costs, and improve product performance. ## Claims ### Claim 1 A method for forming an intermetallic air gap, comprising: S01: forming a trench in a solid dielectric; S02: preparing an insulating sheet-like two-dimensional material, wherein the insulating sheet-like two-dimensional material comprises an insulating nano sheet-like layer, and the size of the insulating nano sheet-like layer in the sheet-like two-dimensional direction is larger than the size of the trench; S03: depositing the insulating sheet-shaped two-dimensional material on the solid dielectric and the trench; S04: annealing the solid dielectric and the insulating sheet-like two-dimensional material to form a stable insulating sheet-like two-dimensional material thin film, thereby forming an intermetallic air gap sealed by the insulating sheet-like two-dimensional material thin film. ### Claim 2 (depends on 1) The method for forming an intermetallic air gap of claim 1, wherein the step S02 further comprises: dissolving the insulating sheet-like two-dimensional material in water and adding an organic solvent to prepare an insulating sheet-shaped two-dimensional material solution; in the step S03, a spin coating process is used to deposit the insulating sheet-shaped two-dimensional material solution on the solid dielectric and the trench, and heat, thereby a thin film composed of the insulating sheet-like two-dimensional material is formed on the solid dielectric and the trench. ### Claim 3 (depends on 1) The method for forming an intermetallic air gap of claim 1, wherein the step S02 further comprises: dissolving the insulating sheet-like two-dimensional material in water and adding an organic solvent to prepare the insulating sheet-like two-dimensional material solution; in the step S03, an immersion thin film-forming process is used to deposit the insulating sheet-shaped two-dimensional material on the solid dielectric and the trench; the step of the immersion thin film-forming process is: immersing the solid dielectric in the insulating sheet-shaped two-dimensional material solution, and the heating causes the solvent to evaporate, thereby forming a thin film composed of an insulating sheet-like two-dimensional material on the solid dielectric and the trench. ### Claim 4 (depends on 3) The method for forming an intermetallic air gap of claim 3, wherein in the immersion thin film forming process, a clamping part is located at the edge of the upper surface of the solid dielectric, and the clamping part is kept at a distance from the edge of the upper surface of the solid dielectric; wherein the surface tension of the insulating sheet-shaped two-dimensional material solution and the material of the solid dielectric and the clamping part are adjusted so that the surface tension of the insulating sheet-shaped two-dimensional material solution is greater than the force between the insulating sheet-shaped two-dimensional material solution and the solid dielectric, and is greater than the force between the insulating sheet-shaped two-dimensional material solution and the clamping part; the contact angles between the insulating sheet-shaped two-dimensional material solution and the solid dielectric is greater than 60°, the contact angles between the insulating sheet-shaped two-dimensional material solution and the clamping part is greater than 60°, so that the insulating sheet-shaped two-dimensional material solution cannot pass through the distance to enter the edge of the upper surface of the solid dielectric, the sidewall of the solid dielectric, and the bottom of the solid dielectric. ### Claim 5 (depends on 3) The method for forming an intermetallic air gap of claim 3, wherein in the immersion thin film forming process, the clamping part is used to cover the bottom, the sidewall and upper surface edge of the solid dielectric. ### Claim 6 (depends on 1) The method for forming an intermetallic air gap of claim 1, wherein the insulating sheet-shaped two-dimensional material is graphene oxide, boron nitride, or Si2BN. ### Claim 7 (depends on 6) The method for forming an intermetallic air gap of claim 6, wherein the process for preparing the graphene oxide solution comprises following steps: S01: dissolving graphene oxide in water, then adding an organic solvent and dissolving the graphene oxide ultrasonically at 55-65° C. to form a stable graphene oxide solution; S02: filtering the graphene oxide solution by a filter membrane with size of M1, and the remaining part after the filtration is the graphene oxide solution after the first filtration; wherein M1 is the size of the trench; S03: filtering the graphene oxide solution by a filter membrane with size of M2, and the filtered part is the graphene oxide solution after the second filtration; wherein M2 is greater than M1. ### Claim 8 (depends on 1) The method for forming an intermetallic air gap of claim 1, wherein the size value of the insulating sheet layer is in a normal distribution, and the center value of the normal distribution is greater than 1.2 times the size of the trench. ### Claim 9 An intermetallic air gap, comprises: a solid dielectric and a trench located in the solid dielectric, the upper surface of the solid dielectric and the trench is covered with a thin film composed of an insulating sheet-like two-dimensional material, and the thin film composed of the insulating sheet-like two-dimensional material seals the trench to form an intermetallic air gap; wherein the insulating sheet-like two-dimensional material comprises an insulating nano sheet-like layer, and the smallest dimension of the insulating nano sheet-like layer in the sheet-like two-dimensional direction is larger than the size of the trench. ### Claim 10 (depends on 9) An intermetallic air gap of claim 9, wherein when the solid dielectric is a metal layer, a dielectric protective layer is comprised between the thin film composed of an insulating sheet-like two-dimensional material and the metal layer, and the sidewall of the trench also comprises a dielectric protection layer.