# US 8,540,890 B2 · Protective treatment for porous materials > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,890 B2 - Document ID: US8540890B2 - Status: Granted - Kind: B2 - Application number: 13/675,442 - Filed: 2012-11-13 - Published: 2013-05-16 - Granted: 2013-09-24 - Earliest claimed: 2011-11-15 - Assignees: Imec; Globalfoundries Inc. - Applicants: Imec; GLOBALFOUNDRIES Inc. - Inventors: Mikhail Baklanov; Francesca Iacopi; Serge Vanhaelemeersch - Web page: https://patentgrep.com/patent/US8540890B2 ## CPC - H01B 19/04: Treating the surfaces, e.g. applying coatings - H10P 50/283: {by chemical means} - H10P 50/287: {by chemical means} - H10P 95/00: Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass - H10W 20/072: {of dielectric parts comprising air gaps} - H10W 20/081: {by forming openings in the dielectric parts} - H10W 20/096: {by contacting with gases, liquids or plasmas} - H10W 20/46: comprising air gaps - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) - 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 ## Abstract A method for treating a surface of a porous material in an environment is provided, comprising setting the temperature of the surface to a value T1 and setting the pressure of the environment to a value P1, contacting the surface with a fluid having a solidifying temperature at the pressure value P1 above the value T1 and having a vaporizing temperature at the pressure value P1 below 80° C., thereby solidifying the fluid in pores of the material, thereby sealing the pores, treating the surface, wherein the treatment is preferably an etching or a modification of the surface, and setting the temperature of the surface to a value T2 and setting the pressure of the environment to a value P2 in such a way as to vaporize the fluid. ## Claims ### Claim 1 A method for treating a surface of a porous material in an environment, comprising: i. setting a temperature of a surface of a porous material to a value T1 and setting a pressure of an environment to a value P1; ii. contacting the surface with a fluid having a solidifying temperature at the pressure value P1 above the temperature value T1 and having a vaporizing temperature at the pressure value P1 below 80° C., thereby solidifying the fluid in pores of the material, thereby sealing the pores; iii. treating the surface by an etching of the surface or by a modification of the surface; and iv. setting the temperature of the surface to a value T2 and setting the pressure of the environment to a value P2 in such a way as to vaporize the fluid, whereby a treated porous material is obtained; wherein: the step i precedes the step ii, the step ii precedes the step iii, and the step iii precedes the step iv, or the step i precedes the step ii, the step ii overlaps or is simultaneous with the step iii, and the step iii precedes the step iv, or the step ii precedes the step i, the step i precedes the step iii, and the step iii precedes the step iv. ### Claim 2 (depends on 1) The method of claim 1, wherein the temperature value T2 is at least equal to the vaporization temperature of the fluid at the pressure value P1 and wherein the pressure value P2 is equal to the pressure value P1. ### Claim 3 (depends on 1) The method of claim 1, wherein the material has a dielectric constant lower than 3.9. ### Claim 4 (depends on 1) The method of claim 1, wherein the material has a dielectric constant lower than 3.5. ### Claim 5 (depends on 1) The method of claim 1, wherein the material has a dielectric constant lower than 3.0. ### Claim 6 (depends on 1) The method of claim 1, wherein the material has a dielectric constant lower than 2.4. ### Claim 7 (depends on 1) The method of claim 1, wherein the porous material is a nanoporous material. ### Claim 8 (depends on 1) The method of claim 1, wherein a porosity of the porous material is at least partly interconnected. ### Claim 9 (depends on 1) The method of claim 1, wherein a porosity of the porous material is fully interconnected. ### Claim 10 (depends on 1) The method of claim 1, wherein the material is a silicon-containing material or a porous organic polymer. ### Claim 11 (depends on 1) The method of claim 1, wherein the temperature value T1 is below 0° C. ### Claim 12 (depends on 1) The method of claim 1, wherein the temperature value T1 is below −5° C. ### Claim 13 (depends on 1) The method of claim 1, wherein treating the surface is plasma treating the surface. ### Claim 14 (depends on 1) The method of claim 1, wherein treating the surface is plasma etching the surface. ### Claim 15 (depends on 1) The method of claim 1, wherein the fluid is an organic fluid. ### Claim 16 (depends on 15) The method of claim 15, wherein the organic fluid has a melting point at 1 atm lower than 10° C. ### Claim 17 (depends on 1) The method of claim 1, wherein the step i is performed by placing the porous material in thermal contact with a bearing having a temperature at the value T1 in such a way that the surface faces away from the bearing. ### Claim 18 (depends on 1) The method of claim 1, wherein the temperature value T2 is from 15° C. to 80° C. ### Claim 19 (depends on 1) The method of claim 1, wherein treating the surface comprises etching the surface so as to form a recess, the method further comprising: v. filling, at least partially, the recess with a metal, wherein the step v is performed after the step iii and before or after the step iv. ### Claim 20 (depends on 1) The method of claim 1, further comprising, before the step i: vi. providing a porous material having a surface bearing a resist layer; and vii. patterning the resist layer so as to expose a surface of the porous material, thereby providing a surface of a porous material, wherein treating the surface comprises etching the surface, thereby forming a recess in the porous material. ### Claim 21 (depends on 1) The method of claim 1, wherein the porous material has trenches in a surface thereof, and wherein the porous material has a k-value lower than 2.5 at a level of the trenches. ### Claim 22 (depends on 1) The method of claim 1, wherein the porous material has trenches in a surface thereof, and wherein the porous material has a k-value lower than 2.3 at a level of the trenches.