# US 9,437,505 B2 · Method of measuring contamination amount of vapor phase growth apparatus, and method of manufacturing epitaxial wafer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,437,505 B2 - Document ID: US9437505B2 - Status: Granted - Kind: B2 - Application number: 14/426,968 - Filed: 2013-09-26 - Published: 2015-08-27 - Granted: 2016-09-06 - Earliest claimed: 2012-10-16 - Assignees: Shin-Etsu Handotai Co., Ltd. - Applicants: Shin-Etsu Handotai Co., Ltd. - Inventors: Takeshi Arai; Satoshi Inada - Web page: https://patentgrep.com/patent/US9437505B2 ## CPC - H10P 74/20: characterised by the properties tested or measured, e.g. structural or electrical properties - C23C 16/4405: {Cleaning of reactor or parts inside the reactor by using reactive gases} - C30B 25/16: Controlling or regulating (controlling or regulating in general G05) - C30B 29/06: Silicon - G01N 33/00: Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00 - G01N 33/0036: {specially adapted to detect a particular component (physical analysis of gaseous biological material G01N33/497)} - H10P 14/279: {Vapour-liquid-solid growth} - H10P 74/203: {Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects} - G01N 33/0095: {Semiconductive materials} - H10P 14/24: using chemical vapour deposition [CVD] - H10P 14/3411: {Silicon, silicon germanium or germanium} - 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) - C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Carry out a vapor etching step of cleaning an inside of a chamber of a vapor phase growth apparatus by vapor etching using HCl gas (S1). Carry out an annealing step of sequentially annealing a predetermined number of silicon wafers, one by one, in a non-oxidizing atmosphere (S2, S3). Repeat the vapor etching step and the annealing step a prescribed number of times. After having carried out the vapor etching step and the annealing step the prescribed number of times (S4: Yes), collect contaminants on the surface of each of the wafers, and measure the Mo concentration using ICP-MS (S5). Evaluate the cleanliness of the vapor phase growth apparatus on the basis of each Mo concentration value and the relationship between the Mo concentrations (S6). Thus, provided is a method with which it is possible to measure, with high sensitivity, the contamination amount of a vapor phase growth apparatus. ## Claims ### Claim 1 A method of measuring an amount of contamination of a vapor phase growth apparatus, comprising: a vapor etching step of cleaning an inside of a chamber of a vapor phase growth apparatus by vapor etching using HCl gas; an annealing step of sequentially annealing a predetermined number of wafers, one by one, in a non-oxidizing atmosphere in the chamber after the vapor etching; and a measurement step of measuring a concentration of a metal impurity on a surface of each of the wafers annealed in the annealing step, as the amount of contamination of the vapor phase growth apparatus, wherein a process which performs the vapor etching step and performs the annealing step for the predetermined number of wafers after the vapor etching step is repeatedly performed a predetermined number of times, the annealing step is performed such that the same wafers are used throughout the repeated annealing step and the order of the wafers to be annealed is not changed throughout the repeated annealing step, and the measurement step is performed after the process has been repeatedly performed the predetermined number of times. ### Claim 2 (depends on 1) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 1, wherein the non-oxidizing atmosphere is a hydrogen atmosphere. ### Claim 3 (depends on 1) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 1, wherein the predetermined number of wafers is three or more wafers. ### Claim 4 (depends on 1) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 1, wherein the predetermined number of times is four or more times. ### Claim 5 (depends on 1) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 1, wherein the annealing is performed at 1000° C. to 1200° C. for 30 seconds or more. ### Claim 6 (depends on 1) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 1, wherein in the measurement step, contamination on the surface of each wafer is collected, and the concentration of the metal impurity contained in the contamination is measured by ICP-MS. ### Claim 7 (depends on 6) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 6, wherein a region from which the contamination is collected is an entire region of the surface of each wafer. ### Claim 8 (depends on 6) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 6, wherein a region from which the contamination is collected is a part of the surface of each wafer. ### Claim 9 (depends on 1) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 1, wherein in the measurement step, a concentration of Mo is measured as the concentration of the metal impurity. ### Claim 10 (depends on 1) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 1, wherein a silicon wafer is used as the wafer. ### Claim 11 (depends on 1) A method of manufacturing an epitaxial wafer, comprising: adopting the method of measuring an amount of contamination of a vapor phase growth apparatus according to of claim 1; and vapor-phase growing an epitaxial film on a wafer by using a vapor phase growth apparatus in which contamination caused by a metal impurity is reduced to or below a certain level, based on a result of measurement performed by the method of measuring an amount of contamination. ### Claim 12 (depends on 1) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 1, wherein: the non-oxidizing atmosphere is a hydrogen atmosphere; and the predetermined number of wafers is three or more wafers. ### Claim 13 (depends on 1) The method of measuring an amount of contamination of a vapor phase growth apparatus according to claim 1, further comprising: an evaluation step of evaluating a cause of metal contamination of the vapor phase growth apparatus, based on a relationship among the concentrations of a metal impurity of the predetermined number of wafers, which are measured by the measuring step.