# US 9,520,270 B2 · Direct current superposition curing for resist reflow temperature enhancement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,270 B2 - Document ID: US9520270B2 - Status: Granted - Kind: B2 - Application number: 14/340,721 - Filed: 2014-07-25 - Published: 2016-01-28 - Granted: 2016-12-13 - Earliest claimed: 2014-07-25 - Assignees: Tokyo Eelctron Limited - Applicants: Tokyo Electron Limited - Inventors: Nihar Mohanty; Akiteru Ko; Chi-Chun Liu - Web page: https://patentgrep.com/patent/US9520270B2 ## CPC - H01J 37/32091: {the radio frequency energy being capacitively coupled to the plasma} - G03F 7/0002: {Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping} - G03F 7/40: Treatment after imagewise removal, e.g. baking - H10P 50/242: {of Group IV materials} - H10P 50/695: {characterised by the process involved to create the mask, e.g. lift-off masks or sidewalls or to modify the mask} - H10P 76/204: {of organic photoresist masks} - H10P 95/08: {Planarisation of organic insulating materials} - B81C 1/00428: {Etch mask forming processes not provided for in groups B81C1/00396 - B81C1/0042} - B81C 2201/0149: Forming nanoscale microstructures using auto-arranging or self-assembling material - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - 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) ## Abstract Techniques herein include methods for curing a layer of material (such as a resist) on a substrate to enable relatively greater heat reflow resistance. Increasing reflow resistance enables successful directed self-assembly of block copolymers. Techniques include receiving a substrate having a patterned photoresist layer and positioning this substrate in a processing chamber of a capacitively coupled plasma system. The patterned photoresist layer is treated with a flux of electrons by coupling negative polarity direct current power to a top electrode of the plasma processing system during plasma processing. The flux of electrons is accelerated from the top electrode with sufficient energy to pass through a plasma and its sheath, and strike the substrate such that the patterned photoresist layer changes in physical properties, which can include an increased glass-liquid transition temperature. ## Claims ### Claim 1 A method of curing a layer of material on a substrate, the method comprising: receiving a substrate having a patterned photoresist layer, the patterned photoresist layer created from a negative tone developer photoresist; positioning the substrate in a processing chamber of a capacitively coupled plasma system; treating the patterned photoresist layer with a flux of electrons by coupling negative polarity direct current power to a top electrode of the plasma processing system, the flux of electrons being accelerated from the top electrode with sufficient energy to pass through a plasma and strike the substrate such that the patterned photoresist layer changes in physical properties, wherein the patterned photoresist layer changing in physical properties includes increasing a value of a glass-liquid transition temperature of the negative tone developer photoresist as compared to prior to being treated with the flux of electrons, wherein the glass-liquid transition temperature of the negative tone developer photoresist is increased above 210 degrees Celsius; dispensing a block copolymer film on the patterned photoresist layer; and activating phase-separation of the block copolymer film to form different polymer features, wherein activating phase separation includes heating the substrate to a temperature sufficient to cause copolymers to segregate resulting in the different polymer features self-assembling within the patterned photoresist layer. ### Claim 2 (depends on 1) The method of claim 1, wherein the plasma is created from a process gas flowed into the processing chamber. ### Claim 3 (depends on 2) The method of claim 2, wherein the process gas comprises hydrogen gas and an inert gas. ### Claim 4 (depends on 2) The method of claim 2, wherein the process gas comprises nitrogen gas and an inert gas. ### Claim 5 (depends on 1) The method of claim 1, wherein the patterned photoresist layer defines multiple holes. ### Claim 6 (depends on 5) The method of claim 5, wherein the defined holes have a critical dimension selected that enables a specified number of divisions from a predetermined block copolymer material. ### Claim 7 (depends on 5) The method of claim 5, wherein the defined holes have a critical dimension selected that enables a specified number of phase separation divisions from a predetermined block copolymer material using a graphoepitaxy directed self-assembly operation. ### Claim 8 (depends on 1) The method of claim 1, wherein the patterned photoresist layer defines multiple trenches. ### Claim 9 (depends on 1) The method of claim 1, further comprising transferring at least a portion of the self-assembled pattern into an underlying layer. ### Claim 10 (depends on 1) The method of claim 1, further comprising: annealing the block copolymer film via a heat treatment that activates self-assembly of the block copolymer film such that the block copolymer film separates into a first polymer and a second polymer; and selectively removing the second polymer such that the first polymer defines a second pattern. ### Claim 11 (depends on 10) The method of claim 10, further comprising transferring the second pattern to an underlying layer via an etch process. ### Claim 12 (depends on 1) The method of claim 1, wherein the capacitively coupled plasma system includes a parallel plate configuration of two electrode plates facing each other.