# US 10,770,294 B2 · Selective atomic layer deposition (ALD) of protective caps to enhance extreme ultra-violet (EUV) etch resistance > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,770,294 B2 - Document ID: US10770294B2 - Status: Granted - Kind: B2 - Application number: 16/447,565 - Filed: 2019-06-20 - Published: 2019-12-26 - Granted: 2020-09-08 - Earliest claimed: 2018-06-22 - Assignees: Tokyo Electron Limited - Applicants: Tokyo Electron Limited - Inventors: David O'Meara; Lior Huli; Soo Doo Chae; Wan Jae Park - Web page: https://patentgrep.com/patent/US10770294B2 ## CPC - H10P 76/4085: {characterised by the processes involved to create the masks} - C23C 16/04: Coating on selected surface areas, e.g. using masks - C23C 16/402: {Silicon dioxide} - C23C 16/403: {of aluminium, magnesium or beryllium} - C23C 16/405: {of refractory metals or yttrium} - C23C 16/45525: {Atomic layer deposition [ALD]} - H10P 14/6339: {deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD} - H10P 14/668: {the materials being characterised by the deposition precursor materials} - H10P 14/69215: {the material being a silicon oxide, e.g. SiO2} - H10P 14/69391: {the material containing aluminium, e.g. Al2O3} - H10P 14/69394: {the material containing titanium, e.g. TiO2} - H10P 50/73: {using masks for insulating materials} - H10P 76/405: {characterised by their composition, e.g. multilayer masks} - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - 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) ## Abstract Methods are disclosed that selectively deposit a protective material on the top regions of patterned photoresist layers, such patterned EUV photoresist layers, to provide a protective cap that reduces erosion damage during etch processes used for pattern transfer. Some deposition of the protective material on the sidewalls of the patterned photoresist layer is acceptable, and any deposition of the protective material on the underlying layer below the patterned photoresist layer is preferably thinner than the deposition at the top of the photoresist pattern. Further, the selective deposition of protective caps can be implemented, for example, through the application of high-rotation speeds to spatial atomic layer deposition (ALD) techniques. The selective deposition of protective caps increases the flexibility of options to improve etch resistance for various processes/materials. ## Claims ### Claim 1 A method of processing microelectronic workpieces, comprising: providing a patterned extreme ultraviolet (EUV) photoresist layer above an underlying layer, the patterned EUV photoresist layer including openings having sidewalls, with the openings forming a pattern for the EUV photoresist layer; depositing a protective material on the patterned EUV photoresist layer using selective atomic layer deposition (ALD) to form protective caps on top regions for the patterned EUV photoresist layer, the protective material comprising aluminum oxide, silicon oxide or titanium oxide; and transferring the pattern for the patterned EUV photoresist layer to the underlying layer using one or more etch processes. ### Claim 2 (depends on 1) The method of claim 1, further comprising forming an EUV photoresist layer over the underlying layer and patterning the EUV photoresist layer to form the patterned EUV photoresist layer; the patterning comprising depositing an EUV material, exposing a first portion of the EUV material to EUV radiation of 20 nm or less, and removing a second portion of the EUV material not exposed to the EUV radiation to form the patterned EUV photoresist layer. ### Claim 3 (depends on 1) The method of claim 1, further comprising removing the protective caps and the patterned EUV photoresist layer after transferring the pattern to the underlying layer. ### Claim 4 (depends on 1) The method of claim 1, wherein the patterned photoresist layer comprises an argon fluoride (ArF) photoresist. ### Claim 5 (depends on 1) The method of claim 1, wherein the underlying layer includes exposed regions exposed through the openings of the patterned EUV photoresist layer prior to depositing the protective material, and the depositing forms the protective caps without covering the exposed regions of the underlying layer. ### Claim 6 (depends on 1) The method of claim 1, wherein the depositing comprises positioning the microelectronic workpiece in an ALD processing tool and rotating the microelectronic workpiece at a speed of at least 200 rpm through a plurality of processing regions within the ALD processing tool to deposit the protective material. ### Claim 7 (depends on 6) The method of claim 6, wherein the depositing of the protective material forms a coating of 1 to 10 nanometers. ### Claim 8 (depends on 6) The method of claim 6, further comprising rotating the microelectronic workpiece through a precursor adsorption region, a separation region of nitrogen N2 flow, and an oxidation and plasma treatment region to complete each layer of deposition. ### Claim 9 (depends on 8) The method of claim 8, further comprising also rotating the microelectronic workpiece through a final separation region of N2 flow for each layer of deposition. ### Claim 10 (depends on 8) The method of claim 8, wherein the protective material is aluminum oxide (Al2O3) and wherein TMA (trimethyl aluminum) is used for the precursor adsorption region for the ALD processing tool. ### Claim 11 (depends on 10) The method of claim 10, wherein a supply for the TMA is reduced in the precursor adsorption region to facilitate selective deposition of the protective material to the top regions of the patterned EUV photoresist layer. ### Claim 12 (depends on 6) The method of claim 6, wherein the protective material is 20-40% thicker at the top regions of the patterned EUV photoresist layer as compared to other regions where the protective material is deposited. ### Claim 13 (depends on 12) The method of claim 12, wherein a thickness of the protective material at the top regions is up to thirty percent of the height that the patterned EUV photoresist layer extends above the underlying layer, and wherein the underlying layer is immediately below the patterned EUV photoresist layer. ### Claim 14 (depends on 13) The method of claim 13, wherein the thickness of the protective material at the top regions is 5 to 30% of a height of the patterned EUV photoresist material. ### Claim 15 (depends on 1) The method according to claim 1, wherein during the ALD, the microelectronic workpiece is rotated through a precursor adsorption region, a separation region of nitrogen flow, and an oxidation and pretreatment region to form each layer of deposition; and wherein in the precursor adsorption region a supply of a precursor is reduced by at least one of pulsing a flow of the precursor or supplying nitrogen with the precursor in the precursor adsorption region. ### Claim 16 (depends on 15) The method according to claim 15, wherein the protective material comprises aluminum oxide, and the precursor includes trimethyl aluminum. ### Claim 17 (depends on 1) The method of claim 1, wherein during transferring of the pattern to the underlying layer, the protective layer is etched and an amount of erosion of the patterned EUV photoresist is 2 percent or less of a height of the patterned EUV photoresist layer. ### Claim 18 A method of processing microelectronic workpieces comprising: providing a patterned extreme ultraviolet (EUV) photoresist layer above an underlying layer, the patterned EUV photoresist layer including openings having sidewalls, with the openings forming a pattern for the EUV photoresist layer, depositing a protective material on the patterned EUV photoresist layer to form protective caps on top regions of the patterned EUV photoresist layer such that a thickness of the protective caps is 5 to 30% of a height of the openings in the patterned EUV photoresist layer, the depositing of the protective material performed using selective atomic layer (ALD) deposition performed while rotating the microelectronic workpiece through a plurality of processing regions at a speed of at least 200 rpm; and transferring the pattern for the patterned EUV photoresist layer to the underlying layer using one or more etch processes. ### Claim 19 (depends on 18) The method according to claim 18, wherein during the ALD, the microelectronic workpiece is rotated through a precursor adsorption region, a separation region of nitrogen flow, and an oxidation and pretreatment region to form each layer of deposition; and wherein in the precursor adsorption region a supply of a precursor is reduced by at least one of pulsing a flow of the precursor or supplying nitrogen with the precursor in the precursor adsorption region. ### Claim 20 (depends on 19) The method of claim 19, wherein the protective material comprises aluminum oxide, silicon oxide, or titanium oxide. ### Claim 21 (depends on 20) The method of claim 20, wherein during transferring of the pattern to the underlying layer, the protective material is etched and an amount of erosion of the patterned EUV photoresist is 2 percent or less of a height of the patterned EUV photoresist layer; and wherein the patterned EUV photoresist layer is formed by exposing an EUV material to EUV radiation of 20 nm or less.