# US 12,531,220 B2 · Automated feedforward and feedback sequence for patterning CD control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,531,220 B2 - Document ID: US12531220B2 - Status: Granted - Kind: B2 - Application number: 17/921,343 - Filed: 2021-05-04 - Published: 2023-06-01 - Granted: 2026-01-20 - Earliest claimed: 2020-05-11 - Assignees: Lam Research Corporation - Applicants: Lam Research Corporation - Inventors: Ravi Kumar; Pulkit Agarwal; Michael Philip Roberts; Ramesh Chandrasekharan; Adrien Lavoie - Web page: https://patentgrep.com/patent/US12531220B2 ## CPC - H01J 37/3299: {Feedback systems} - H01J 37/32724: {Temperature} - H01J 37/32926: {Software, data control or modelling} - H10P 14/6339: {deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD} - H10P 50/283: {by chemical means} - H10P 50/73: {using masks for insulating materials} - H10P 74/23: {characterised by multiple measurements, corrections, marking or sorting processes} - H10P 76/4085: {characterised by the processes involved to create the masks} - H01J 2237/3321: CVD [Chemical Vapor Deposition] - H01J 2237/3323: uniformity - H01J 2237/3325: large area - H01J 2237/3341: Reactive etching - H10P 14/69215: {the material being a silicon oxide, e.g. SiO2} - H10P 72/0466: {characterised by the construction of the load-lock chamber} - H10P 74/203: {Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects} - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A method for performing a feedback sequence for patterning CD control. The method including performing a series of process steps on a wafer to obtain a plurality of features, wherein a process step is performed under a process condition. The method including measuring a dimension of the plurality of features after performing the series of process steps. The method including determining a difference between the dimension that is measured and a target dimension for the plurality of features. The method including modifying the process condition for the process step based on the difference and a sensitivity factor for the plurality of features relating change in dimension and change in process condition. ## Claims ### Claim 1 A method, comprising: performing a series of process steps on a first plurality of test wafers, each of the first plurality of test wafers forming a plurality of features, wherein a first process step in the series of process steps is performed under a first process condition, wherein the series of process steps includes at least one process step; performing the series of process steps on a second plurality of test wafers, each of the second plurality of test wafers forming the plurality of features, wherein the first process step is performed under a second process condition; measuring a first dimension of the plurality of features located on the first plurality of test wafers; measuring a second dimension of the plurality of features located on the second plurality of test wafers; and determining a sensitivity factor for the plurality of features relating change in dimension and change in process condition. ### Claim 2 (depends on 1) The method of claim 1, wherein the determining includes: determining the sensitivity factor based on a difference between the first process condition and the second process condition, and based on a difference between the first dimension and the second dimension. ### Claim 3 (depends on 1) The method of claim 1, wherein the first process condition is a first temperature of a pedestal configured to support a test wafer, the first process step being an etch process step, wherein the second process condition is a second temperature of the pedestal. ### Claim 4 (depends on 3) The method of claim 3, wherein the sensitivity factor is a trim sensitivity factor relating a change in dimension of the plurality of features and a change in temperature of the pedestal when performing an etch process step as the first process step. ### Claim 5 (depends on 1) The method of claim 1, wherein the first process condition is a first time period for performing an etch process step as the first process step, wherein the second process condition is a second time period for performing a trim process step. ### Claim 6 (depends on 5) The method of claim 5, wherein the sensitivity factor is a trim sensitivity factor relating a change in dimension of the plurality of features and a change in time when performing the etch process step. ### Claim 7 (depends on 1) The method of claim 1, wherein the first process condition is a first temperature of a pedestal configured for wafer support, the first process step being a deposition step, wherein the second process condition is a second temperature of the pedestal. ### Claim 8 (depends on 7) The method of claim 7, wherein the sensitivity factor is a deposition sensitivity factor relating a change in dimension of the plurality of features and change in temperature of the pedestal when performing the deposition step. ### Claim 9 (depends on 1) The method of claim 1, wherein the first process condition is a first number of cycles of a deposition step that is the first process step, wherein the second process condition is a second number of cycles of the deposition step. ### Claim 10 (depends on 9) The method of claim 9, wherein the sensitivity factor is a deposition sensitivity factor relating a change in dimension of the plurality of features and a change in a number of atomic layer deposition cycles when performing the deposition step. ### Claim 11 (depends on 1) The method of claim 1, wherein the measuring the first dimension includes: measuring each of the plurality of features on the first plurality of test wafers to determine a plurality of dimensions; and determining an average of the plurality of dimensions that is the first dimension. ### Claim 12 (depends on 11) The method of claim 11, wherein the each of the plurality of features is measured at an end of the series of process steps, wherein the series of process steps is a self-aligned double patterning (SADP) process, wherein the first process step is included in a first patterning of the SADP process. ### Claim 13 (depends on 11) The method of claim 11, wherein the each of the plurality of features is measured at an end of the first process step. ### Claim 14 (depends on 1) The method of claim 1, wherein the measuring the second dimension includes: measuring each of the plurality of features on the second plurality of test wafers to determine a plurality of dimensions; and determining an average of the plurality of dimensions that is the second dimension. ### Claim 15 (depends on 14) The method of claim 14, wherein the each of the plurality of features is measured at an end of the series of process steps, wherein the series of process steps is a self-aligned double patterning (SADP) process, wherein the first process step is included in a first patterning of the SADP process. ### Claim 16 (depends on 14) The method of claim 14, wherein the each of the plurality of features is measured at an end of the first process step. ### Claim 17 (depends on 1) The method of claim 1, wherein each of the first plurality of test wafers and each of the second plurality of test wafers is a blanket wafer. ### Claim 18 (depends on 1) The method of claim 1, wherein each of the first plurality of test wafers and each of the second plurality of test wafers is a topographic wafer. ### Claim 19 A method comprising: performing a series of process steps on a wafer to obtain a plurality of features, wherein a process step is performed under a process condition; measuring a dimension of the plurality of features after performing the series of process steps; determining a difference between the dimension of the plurality of features that is measured and a target dimension for the plurality of features; and modifying the process condition for the process step based on the difference and a sensitivity factor for the plurality of features relating change in dimension and change in process condition, wherein the modifying the process condition includes modifying a temperature of a pedestal configured for wafer support, the temperature used when performing the process step that is an etch process step, wherein the sensitivity factor is a trim sensitivity factor relating a change in the dimension of the plurality of features and a change in temperature of the pedestal when performing the etch process step. ### Claim 20 (depends on 19) The method of claim 19, further comprising: performing the series of process steps using the process condition that is modified for the process step performed on another wafer. ### Claim 21 (depends on 19) The method of claim 19, wherein the measuring the dimension includes: measuring each of the plurality of features to determine a plurality of dimensions; and determining an average of the plurality of dimensions, the average being the dimension. ### Claim 22 (depends on 21) The method of claim 21, wherein the each of the plurality of features is measured at an end of the series of process steps, wherein the series of process steps is a self-aligned double patterning (SADP) process, wherein the process step is included in a first patterning of the SADP process. ### Claim 23 A method, comprising: measuring an incoming ADI dimension of a mandrel on a wafer; determining a difference between the incoming ADI dimension and a desired ADI dimension of the mandrel; modifying a time for performing an etch process step based on the difference and an etch rate of the etch process step to achieve a desired ADT dimension of a core feature based on the incoming ADI dimension, the core feature being formed when performing a first patterning process of a self-aligned double patterning (SADP) process; receiving a change in a second patterning process of the SADP process; determining a modified ASD dimension for an oxide layer over the core feature based on the change in the second patterning process; and determining a number of deposition cycles when performing an atomic layer deposition (ALD) process to achieve the modified ASD dimension based on a deposition rate of the ALD process and the desired ADT dimension of the core feature. ### Claim 24 (depends on 23) The method of claim 23, further comprising: performing the number of deposition cycles in the ALD process that is performed within the first patterning process. ### Claim 25 (depends on 23) The method of claim 23, wherein the change in the second patterning process is a change in a dry etch process. ### Claim 26 (depends on 23) The method of claim 23, wherein the determining the difference includes: determining that the incoming ADI dimension is larger than the desired ADI dimension. ### Claim 27 (depends on 23) The method of claim 23, wherein the determining the difference includes: determining that the incoming ADI dimension is smaller than the desired ADI dimension. ### Claim 28 (depends on 23) The method of claim 23, further comprising: determining the etch rate based on a sensitivity factor relating a change in ADI dimension and change in time to determine the etch rate. ### Claim 29 (depends on 23) The method of claim 23, further comprising: determining the deposition rate of the ALD process based on a sensitivity factor relating a change in ASD dimension per deposition cycle. ### Claim 30 A method comprising: performing a series of process steps on a wafer to obtain a plurality of features, wherein a process step is performed under a process condition; measuring a dimension of the plurality of features after performing the series of process steps; determining a difference between the dimension of the plurality of features that is measured and a target dimension for the plurality of features; and modifying the process condition for the process step based on the difference and a sensitivity factor for the plurality of features relating change in dimension and change in process condition, wherein the modifying the process condition includes modifying a time for performing the process step that is an etch process step, wherein the sensitivity factor is a trim sensitivity factor relating a change in the dimension of the plurality of features and a change in time when performing the etch process step. ### Claim 31 A method comprising: performing a series of process steps on a wafer to obtain a plurality of features, wherein a process step is performed under a process condition; measuring a dimension of the plurality of features after performing the series of process steps; determining a difference between the dimension of the plurality of features that is measured and a target dimension for the plurality of features; and modifying the process condition for the process step based on the difference and a sensitivity factor for the plurality of features relating change in dimension and change in process condition, wherein the modifying the process condition includes modifying a temperature of a pedestal configured for wafer support, the temperature used when performing the process step that is a deposition step, wherein the sensitivity factor is a deposition sensitivity factor relating a change in the dimension of the plurality of features and a change in temperature of the pedestal when performing the deposition step. ### Claim 32 A method comprising: performing a series of process steps on a wafer to obtain a plurality of features, wherein a process step is performed under a process condition; measuring a dimension of the plurality of features after performing the series of process steps; determining a difference between the dimension of the plurality of features that is measured and a target dimension for the plurality of features; and modifying the process condition for the process step based on the difference and a sensitivity factor for the plurality of features relating change in dimension and change in process condition, wherein the modifying the process condition includes modifying a number of cycles of a deposition step that is the process step, wherein the sensitivity factor is a deposition sensitivity factor relating a change in the dimension of the plurality of features and a change in a number of atomic layer deposition cycles when performing the deposition step.