# US 10,246,772 B2 · Plasma enhanced chemical vapor deposition of films for improved vertical etch performance in 3D NAND memory devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,246,772 B2 - Document ID: US10246772B2 - Status: Granted - Kind: B2 - Application number: 15/063,569 - Filed: 2016-03-08 - Published: 2016-10-06 - Granted: 2019-04-02 - Earliest claimed: 2015-04-01 - Assignees: Applied Materials, Inc. - Applicants: Applied Materials, Inc. - Inventors: Praket P. Jha; Allen Ko; Xinhai Han; Thomas Jongwan Kwon; Bok Hoen Kim; Byung Ho Kil; Ryeun Kim; Sang Hyuk Kim - Web page: https://patentgrep.com/patent/US10246772B2 ## CPC - C23C 16/345: {Silicon nitride} - C23C 16/401: {containing silicon} - C23C 16/45523: {Pulsed gas flow or change of composition over time} - H10P 14/6336: {in the presence of a plasma [PECVD]} - H10P 14/6682: {the compound being a silane, e.g. disilane, methylsilane or chlorosilane} - H10P 14/6686: {the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane} - H10P 14/69215: {the material being a silicon oxide, e.g. SiO2} - H10P 14/69433: {the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz} - H10P 50/283: {by chemical means} - H10B 41/27: the channels comprising vertical portions, e.g. U-shaped channels - H10B 43/27: the channels comprising vertical portions, e.g. U-shaped channels - 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) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10B: ELECTRONIC MEMORY DEVICES ## Abstract A method for forming a high aspect ratio feature is disclosed. The method includes depositing one or more silicon oxide/silicon nitride containing stacks on a substrate by depositing a first film layer on the substrate from a first plasma and depositing a second film layer having a refractive index on the first film layer from a second plasma. A predetermined number of first film layers and second film layers are deposited on the substrate. The first film layer and the second film layer are either a silicon oxide layer or a silicon nitride layer and the first film layer is different from the second film layer. The method further includes depositing a third film layer from a third plasma and depositing a fourth film layer on the third film layer from a fourth plasma. The fourth film layer has a refractive index greater than the first refractive index. ## Claims ### Claim 1 A method for forming a high aspect ratio feature, comprising: depositing one or more silicon oxide/silicon nitride containing stacks on a substrate positioned in a processing chamber and in the presence of a vacuum, wherein depositing the one or more silicon oxide/silicon nitride containing stacks comprises: (a) energizing a first process gas into a first plasma; (b) depositing a first film layer on the substrate from the first plasma; (c) energizing a second process gas into a second plasma; (d) depositing a second film layer on the first film layer from the second plasma, wherein the second film layer has a refractive index; repeating (a), (b), (c), and (d) until a predetermined number of first film layers and second film layers have been deposited on the substrate, wherein the first film layer is a silicon oxide layer and the second film layer is a silicon nitride layer; (e) energizing a third process gas into a third plasma; (f) depositing a third film layer on a previous layer from the third plasma; (g) energizing a fourth process gas into a fourth plasma; (h) depositing a fourth film layer on the third film layer from the fourth plasma, wherein the fourth film layer has a refractive index greater than the refractive index of the second film layer; repeating (e), (f), (g), and (h) until a predetermined number of third film layers and fourth film layers have been deposited, wherein the third film layer is a silicon oxide layer and the fourth film layer is a silicon nitride layer; and forming one or more high aspect ratio features in the one or more silicon oxide/silicon nitride containing stacks using plasma etching or wet etching techniques, wherein the high aspect ratio feature has a height to width ratio of at least about 5:1 or more. ### Claim 2 (depends on 1) The method of claim 1, wherein the first process gas comprises a silicon-containing gas and an oxygen-containing gas. ### Claim 3 (depends on 2) The method of claim 2, wherein the silicon-containing gas is tetraethyl orthosilicate (TEOS) and the oxygen-containing gas is N2O. ### Claim 4 (depends on 3) The method of claim 3, wherein the second process gas comprises a silicon-containing gas and a nitrogen-containing gas. ### Claim 5 (depends on 4) The method of claim 4, wherein the silicon-containing gas is silane (SiH4) and the nitrogen-containing gas is NH3. ### Claim 6 (depends on 1) The method of claim 1, wherein the second process gas and the fourth process gas each comprise a nitrogen-containing gas and a flow rate of the nitrogen-containing gas in the fourth process gas is increased relative to a flow rate of the nitrogen-containing gas in the second process gas. ### Claim 7 (depends on 1) The method of claim 1, wherein the second process gas and the fourth process gas each comprise a silicon-containing gas and a flow rate of the silicon-containing gas in the fourth process gas is increased relative to a flow rate of the silicon-containing gas in the second process gas. ### Claim 8 (depends on 1) The method of claim 1, wherein the high aspect ratio feature has a height to width ratio of about 10:1 to about 20:1. ### Claim 9 (depends on 1) The method of claim 1, further comprising: (i) energizing a fifth process gas into a fifth plasma; (j) depositing a fifth film layer on a previous layer from the fifth plasma; (k) energizing a sixth process gas into a sixth plasma; (l) depositing a sixth film layer on the fifth film layer from the sixth plasma, wherein the sixth film layer has a refractive index greater than the refractive index of the fourth film layer; and repeating (i), (j), (k), and (l) until a predetermined number of fifth film layers and sixth film layers have been deposited on the substrate, wherein the fifth film layer is a silicon oxide layer and the sixth film layer is a silicon nitride layer. ### Claim 10 (depends on 9) The method of claim 9, wherein the refractive index of the second film layer is from about 1.85 to about 1.90, the refractive index of the fourth film layer is from about 1.91 to about 1.95, and the refractive index of the sixth film layer is from about 1.95 to about 2.1. ### Claim 11 (depends on 1) The method of claim 1, further comprising forming one or more patterning layers over the one or more silicon oxide/silicon nitride containing stacks prior to forming one or more high aspect ratio features in the one or more silicon oxide/silicon nitride containing stacks. ### Claim 12 (depends on 9) The method of claim 9, wherein the second film layer has a thickness from about 10 nanometers to about 60 nanometers, the fourth film layer has a thickness from about 10 nanometers to about 60 nanometers, and the sixth film layer has a thickness from about 10 nanometers to about 60 nanometers. ### Claim 13 A method for forming a high aspect ratio feature, comprising: depositing one or more silicon oxide/silicon nitride containing stacks on a substrate positioned in a processing chamber and in the presence of a vacuum, wherein depositing the one or more silicon oxide/silicon nitride containing stacks comprises: (a) energizing a first process gas into a first plasma; (b) depositing a first film layer on the substrate from the first plasma; (c) energizing a second process gas into a second plasma; (d) depositing a second film layer on the first film layer from the second plasma, wherein the second film layer has a refractive index from about 1.85 to about 1.90; repeating (a), (b), (c), and (d) until a predetermined number of first film layers and second film layers have been deposited on the substrate, wherein the first film layer is a silicon oxide layer and the second film layer is a silicon nitride layer; (e) energizing a third process gas into a third plasma; (f) depositing a third film layer on a previous layer from the third plasma; (g) energizing a fourth process gas into a fourth plasma; (h) depositing a fourth film layer on the third film layer from the fourth plasma, wherein the fourth film layer has a refractive index from about 1.91 to about 1.95; repeating (e), (f), (g), and (h) until a predetermined number of third film layers and fourth film layers have been deposited, wherein the third film layer is a silicon oxide layer and the fourth film layer is a silicon nitride layer; and forming one or more high aspect ratio features in the one or more silicon oxide/silicon nitride containing stacks using plasma etching techniques, wherein the high aspect ratio feature has a height to width ratio of at least about 5:1 or more. ### Claim 14 (depends on 13) The method of claim 13, wherein the first process gas comprises a silicon-containing gas and an oxygen-containing gas. ### Claim 15 (depends on 14) The method of claim 14, wherein the silicon-containing gas is tetraethyl orthosilicate (TEOS) and the oxygen-containing gas is N2O. ### Claim 16 (depends on 15) The method of claim 15, wherein the second process gas comprises a silicon-containing gas and a nitrogen-containing gas. ### Claim 17 (depends on 16) The method of claim 16, wherein the silicon-containing gas is silane (SiH4) and the nitrogen-containing gas is NH3. ### Claim 18 (depends on 13) The method of claim 13, wherein the second process gas and the fourth process gas each comprise a nitrogen-containing gas and a flow rate of the nitrogen-containing gas in the fourth process gas is increased relative to a flow rate of the nitrogen-containing gas in the second process gas. ### Claim 19 (depends on 13) The method of claim 13, wherein the second process gas and the fourth process gas each comprise a silicon-containing gas and a flow rate of the silicon-containing gas in the fourth process gas is increased relative to a flow rate of the silicon-containing gas in the second process gas. ### Claim 20 (depends on 13) The method of claim 13, wherein the high aspect ratio feature has a height to width ratio of about 10:1 to about 20:1.