# US 2020/0399758 A1 · Techniques for controlling precursors in chemical deposition processes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0399758 A1 - Document ID: US20200399758A1 - Status: Published application - Kind: A1 - Application number: 17/012,980 - Filed: 2020-09-04 - Published: 2020-12-24 - Earliest claimed: 2017-12-29 - Assignees: Varian Semiconductor Equipment Associates, Inc. - Applicants: Varian Semiconductor Equipment Associates, Inc. - Inventors: Elaina Babayan; Sarah White; Vijay Venugopal; Jonathan Bakke - Web page: https://patentgrep.com/patent/US20200399758A1 ## CPC - C23C 16/52: Controlling or regulating the coating process {(C23C16/45557, C23C16/279 take precedence)} - C23C 16/448: characterised by the method used for generating reactive gas streams, e.g. by evaporation or sublimation of precursor materials - C23C 16/45544: {characterized by the apparatus} - C23C 16/45553: {characterized by the use of precursors specially adapted for ALD} - G01F 1/00: Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow (measuring a proportion of the volume flow G01F5/00) - G05D 11/00: Control of flow ratio (control of chemical or physico-chemical variables, e.g. pH-value, G05D21/00; control of humidity G05D22/00; control of temperature by varying the mixing ratio of two fluids having different temperatures G05D23/13; control of viscosity G05D24/00) - G05D 11/132: {by controlling the flow of the individual components (G05D11/133 takes precedence)} - G05D 16/00: Control of fluid pressure - G05D 16/04: without auxiliary power - G05D 16/0402: {with two or more controllers mounted in series} - H10P 72/0604: {Process monitoring, e.g. flow or thickness monitoring} - H10P 74/00: Testing or measuring during manufacture or treatment of wafers, substrates or devices - H10P 95/00: Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass - 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) - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract An apparatus for controlling precursor flow. The apparatus may include a processor; and a memory unit coupled to the processor, including a flux control routine. The flux control routine may be operative on the processor to monitor the precursor flow and may include a flux calculation processor to determine a precursor flux value based upon a change in detected signal intensity received from a cell of a gas delivery system to deliver a precursor. ## Claims ### Claim 1 An apparatus for controlling precursor flow, comprising: an ampoule to output a precursor; a sensor assembly communicatively coupled to the source, and comprising: a cell, coupled to the source, to receive and conduct the precursor; a detector, to detect light transmitted through the cell; and a control system, the control system arranged to determine a precursor flux value based upon a change in detected light intensity received from the cell during flow of the precursor through the cell, the control system comprising: a temperature control processor, configured to: determine a flux error value based upon the precursor flux value; determine a temperature adjustment ΔT, based upon the flux error value; and calculate a new set of temperature setpoints to be applied to the ampoule; and an end-of-life processor, the end-of-life processor configured to: check for an end-of ampoule-life condition when the new set of temperature setpoints is not within the predetermined set of temperature limits. ### Claim 2 (depends on 1) The apparatus of claim 1, comprising a flux calculation processor to determine the precursor flux value by: receiving a first reference signal in the cell, generated at a first instance, the first reference signal indicative of a detector performance at the first instance for a detector, the detector to detect a light intensity from a light source; receiving a background signal, generated at the first instance, the background signal being generated by the detector; receiving a second reference signal, generated at a second instance, subsequent to the first instance, the second reference signal indicative of the detector performance at the second instance for the detector; and receiving a precursor signal, generated at a third instance, subsequent to the first instance, when the precursor is flowing in the cell. ### Claim 3 (depends on 1) The apparatus of claim 1, the temperature control processor configured to: determine a warning band condition based upon the precursor flux value; and adjust a temperature of the ampoule based upon the warning band condition. ### Claim 4 (depends on 1) The apparatus of claim 1, the flux calculation processor configured to calculate an integrated flux of the precursor by determining the precursor flux value at a plurality of instances. ### Claim 5 (depends on 1) The apparatus of claim 1, the temperature control processor configured to adjust the temperature by: determining a temperature adjustment ΔT, where ΔT=P*€+D*d€/dt+I*∫€/dt, where P, I and D are a proportional, integral, and derivative gains, and where € is an error based upon current temperature limits of the ampoule. ### Claim 6 (depends on 1) The apparatus of claim 1 the temperature control processor configured to adjust a temperature of the ampoule by: applying the new set of temperature setpoints to control heating of the ampoule when the new set of temperature setpoints are within a predetermined set of temperature limits. ### Claim 7 (depends on 1) The apparatus of claim 1, the end-of-life processor configured to: recalculate ΔT to generate a conservative ΔT based upon a most conservative limit when the end-of ampoule life condition has not been met; and calculate the new set of temperature setpoints to be applied to the ampoule based upon the conservative ΔT. ### Claim 8 (depends on 1) The apparatus of claim 1, the flux control routine further comprising an excursion processor, the excursion processor configured to: determine a fault condition based upon the precursor flux value; and send a notification signal of an excursion, when a substrate being processed is during the fault condition is not a first substrate. ### Claim 9 (depends on 1) The apparatus of claim 1, the flux control routine further comprising a clog detection processor, the clog detection processor configured to: receive a cell pressure reading for the cell; receive the precursor flux value; and determine a clog location based upon the cell pressure reading and precursor flux value. ### Claim 10 A method of controlling precursor flow, comprising: measuring a change in detected signal intensity in a cell of the gas delivery system, caused by the flow of a precursor; determining a precursor flux value based upon the change in the detected signal intensity; determining a flux error value based upon the precursor flux value; calculating a new set of temperature setpoints to be applied to the ampoule; and checking for an end-of ampoule-life condition when the new set of temperature setpoints is not within a predetermined set of temperature limits. ### Claim 11 (depends on 10) The method of claim 10, wherein the measuring the change comprises: receiving a first reference signal in the cell at a first instance, the first reference signal indicative of a detector performance at the first instance for a detector, the detector to detect a light intensity from a light source; receiving a background signal at the first instance, the background signal being generated by the detector; receiving a second reference signal at a second instance, subsequent to the first instance, the second reference signal indicative of the detector performance at the second instance for the detector; and receiving a precursor signal from the detector at a third instance, subsequent to the first instance, when the precursor is flowing in the cell and light is generated by the light source. ### Claim 12 (depends on 10) The method of claim 10, wherein the providing the flow of the precursor comprises providing a plurality of pulses at a plurality of instances of the precursor, the method further comprising calculating an integrated flux of the precursor based upon determining the precursor flux value at the plurality of instances. ### Claim 13 (depends on 10) The method of claim 10, further comprising: determining a warning band condition based upon the precursor flux value; and adjusting a temperature of the ampoule based upon the warning band condition. ### Claim 14 (depends on 13) The method of claim 13, wherein the adjusting the temperature comprises: determining a temperature adjustment ΔT, where ΔT=P*€+D*d€/dt+I*∫€/dt, where P, I and D are a proportional, integral, and derivative gains, and where € is an error based upon current temperature limits of the ampoule. ### Claim 15 (depends on 13) The method of claim 13, wherein the adjusting the temperature comprises: applying the new set of temperature setpoints to control heating of the ampoule when the new set of temperature setpoints are within the predetermined set of temperature limits. ### Claim 16 (depends on 15) The method of claim 15, wherein the adjusting the temperature comprises: recalculating ΔT to generate a conservative ΔT based upon a most conservative limit when the end-of ampoule life condition has not been met; and calculating the new set of temperature setpoints to be applied to the ampoule based upon the conservative ΔT. ### Claim 17 (depends on 10) The method of claim 10, further comprising: determining a fault condition based upon the precursor flux value; and sending a notification signal of an excursion, when a substrate being processed is during the fault condition is not a first substrate. ### Claim 18 A method, comprising: determining a precursor flux value based upon a change in detected signal intensity received from a cell of a gas delivery system to deliver a precursor; determining a flux error value based upon the precursor flux value; determining a temperature adjustment ΔT, based upon the flux error value; calculating a new set of temperature setpoints to be applied to the ampoule; and checking for an end-of ampoule-life condition when the new set of temperature setpoints is not within the predetermined set of temperature limits. ### Claim 19 (depends on 18) The method of claim 18, comprising determining the precursor flux value by: receiving a first reference signal in the cell, generated at a first instance, the first reference signal indicative of a detector performance at the first instance for a detector, the detector to detect a light intensity from a light source; receiving a background signal, generated at the first instance, the background signal being generated by the detector; receiving a second reference signal, generated at a second instance, subsequent to the first instance, the second reference signal indicative of the detector performance at the second instance for the detector; and receiving a precursor signal, generated at a third instance, subsequent to the first instance, when the precursor is flowing in the cell. ### Claim 20 (depends on 18) The method of claim 18, further comprising: applying the new set of temperature setpoints to control heating of the ampoule when the new set of temperature setpoints are within a predetermined set of temperature limits.