US7050880B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical-mechanical planarization controller
Assignee: SC Solutions
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Filing: 2003-12-30
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Granted: 2006-05-23
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Expires: 2023-12-30
Abstract
Abstract The invention provides a model-based control approach to chemical-mechanical planarization (CMP) control. The preferred embodiment comprises mathematical models of the CMP process. These models play a critical role in obtaining superior control performance. Model-based Control Design involves the construction of a dynamic mathematical model of the system to be controlled, e.g. a removal rate model of a CMP system. The model can then be evaluated via computer simulations, and validated using data from the system. The invention provides a method and apparatus that processes in-situ data from a suite of real-time sensors and produces real-time commands to multiple actuators, such as applied pressures, slurry-flow rate, and wafer/pad velocity. A key aspect of the invention is an integrated model-based pressure-temperature-velocity-slurry flow control system that includes many innovations in real-time mode identification, real-time gain estimation, and real-time control.
Inventors
- 👤 Dirk de Roover
- 👤 Abbas Emami-Naeini
- 👤 Jon Lloyd Ebert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:54
CPC Classifications
G; G05; G05B; G05B17/00; G05B17/02; G05B2219/00; G05B2219/30; G05B2219/32; G05B2219/32342; G05B2219/45; G05B2219/45232; Y; Y02; Y02P; Y02P90/00; Y02P90/02
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
76 words
A method for controlling a chemical-mechanical planarization (CMP) system, comprising the steps of: providing an integrated model-based pressure-temperature-velocity-slurry flow control system comprising real-time mode identification, real-time gain estimation, and real-time control, said model comprising a plurality of component models of said CMP system: said control system processing in-situ data from a plurality of real-time sensors in said CMP system; and said control system producing real-time commands to a plurality of actuators to control said CMP system.
Claim 2
Independent Claim
76 words
A method for controlling a chemical-mechanical planarization (CMP) system, comprising the steps of: providing an integrated model-based pressure-temperature-velocity-slurry flow control system comprising real-time mode identification, real-time gain estimation, and real-time control, said model comprising a plurality of component models of said CMP system: said control system processing in-situ data from a plurality of real-time sensors in said CMP system; and said control system producing real-time commands to a plurality of actuators to control said CMP system.
Claim 3
Dependent Claim
40 words
The method of claim 1 , said model comprising: an advanced dynamic CMP model having externally controllable variables as inputs; wherein said model predicts a material removal rate and temperature as a function of time and location on a wafer.
Claim 4
Dependent Claim
87 words
The method of claim 1 , wherein said component models comprise any of: a contact mechanical model for predicting contact pressure and relative velocity between a polishing pad and a wafer surface; a chemical and mechanical model for predicting local removal rate as a function of local slurry, pad, and wafer properties; a transport model for predicting distribution of slurry, pad, and wafer properties across a wafer/pad interface; and a thermal model for predicting temperature distribution at said wafer/pad interface necessary for accurate chemistry and transport modeling.
Claim 5
Dependent Claim
11 words
The method of claim 3 , wherein said models are interdependent.
Claim 6
Dependent Claim
20 words
The method of claim 2 , wherein said inputs comprise any of: applied pressures, slurry flow rate, and wafer/platen velocity.
Claim 7
Independent Claim
87 words
An apparatus for controlling a chemical-mechanical planarization (CMP) system, comprising: a plurality of real-time sensors in said CMP system; a plurality of actuators for controlling said CMP system; and an integrated model-based pressure-temperature-velocity-slurry flow control system comprising real-time mode identification, real-time gain estimation, and real-time control; said model comprising a plurality of component models of said OMP system; said control system processing in-situ data from said real-time sensors in said CMP system; and said control system producing real-time commands to said actuators to control said CMP system.
Claim 8
Independent Claim
87 words
An apparatus for controlling a chemical-mechanical planarization (CMP) system, comprising: a plurality of real-time sensors in said CMP system; a plurality of actuators for controlling said CMP system; and an integrated model-based pressure-temperature-velocity-slurry flow control system comprising real-time mode identification, real-time gain estimation, and real-time control; said model comprising a plurality of component models of said OMP system; said control system processing in-situ data from said real-time sensors in said CMP system; and said control system producing real-time commands to said actuators to control said CMP system.
Claim 9
Dependent Claim
40 words
The apparatus of claim 6 , said model comprising: an advanced dynamic CMP model having externally controllable variables as inputs; wherein said model predicts a material removal rate and temperature as a function of time and location on a wafer.
Claim 10
Dependent Claim
87 words
The apparatus of claim 6 , wherein said component models comprise any of: a contact mechanical model for predicting contact pressure and relative velocity between a polishing pad and a wafer surface; a chemical and mechanical model for predicting local removal rate as a function of local slurry, pad, and wafer properties; a transport model for predicting distribution of slurry, pad, and wafer properties across a wafer/pad interface; and a thermal model for predicting temperature distribution at said wafer/pad interface necessary far accurate chemistry and transport modeling.
Claim 11
Dependent Claim
11 words
The apparatus of claim 8 , wherein said models are interdependent.
Claim 12
Dependent Claim
20 words
The apparatus of claim 7 , wherein said inputs comprise any of: applied pressures, slurry flow rate, and wafer/platen velocity.
Claim 13
Dependent Claim
119 words
A chemical-mechanical planarization (CMP) system controller, comprising: a temperature control module for controlling average polishing pad temperature responsive to temperatures measured by any of an in-situ temperature sensor and a thermal model; a pressure profile control module for controlling individual zone pressures for a multi-zone pressure CMP process to provide in-situ pressure feedback using in-situ wafer thickness measurements, as obtained with an in-situ thickness sensor, to adjust pressures in-situ; a slurry flow control module for controlling slurry flow to said CMP system; a motor velocity control module; and a post scaling for temperature control module for post-scaling all control variables, wherein net temperature increase or decrease from individual control variables is counteracted by total scaling of all control variables.
Claim 14
Dependent Claim
119 words
A chemical-mechanical planarization (CMP) system controller, comprising: a temperature control module for controlling average polishing pad temperature responsive to temperatures measured by any of an in-situ temperature sensor and a thermal model; a pressure profile control module for controlling individual zone pressures for a multi-zone pressure CMP process to provide in-situ pressure feedback using in-situ wafer thickness measurements, as obtained with an in-situ thickness sensor, to adjust pressures in-situ; a slurry flow control module for controlling slurry flow to said CMP system; a motor velocity control module; and a post scaling for temperature control module for post-scaling all control variables, wherein net temperature increase or decrease from individual control variables is counteracted by total scaling of all control variables.
Claim 15
Dependent Claim
132 words
The controller of claim 11 , said temperature control module comprising: a mode shape identification element for defining maximum planarization achievable by said CMP system; a master control loop for indirectly controlling average wafer/pad temperature by actuating any of input pressures, slurry flow rate, and wafer/pad velocities; and a dynamic temperature model and a dynamic temperature reference model, both of which describe evolution of average wafer/pad temperature over time; wherein said dynamic temperature model describes wafer/pad temperature, is optional, and can be replaced by a temperature measurement if a temperature sensor is available; and wherein said dynamic temperature reference model describes desired or reference wafer/pad temperature and is driven by said master control loop; wherein wafer/pad temperature is predicted as a function of any of input pressures, slurry flow, and wafer/pad velocity.
Claim 16
Dependent Claim
23 words
The controller of claim 11 , wherein a motor electrical power sensor is used for temperature sensing in lieu of a temperature sensor.
Claim 17
Dependent Claim
20 words
The controller of claim 12 , further comprising: a pressure slave loop comprising a feedback controller combined with feedforward control.
Claim 18
Dependent Claim
45 words
The controller of claim 12 , further comprising: any of a slurry flow and a velocity slave loop, each of which is fed by set point values from said master control loop; wherein any of slurry flow and velocity are used to control wafer/pad temperature.
Claim 19
Dependent Claim
106 words
The controller of claim 11 , said pressure profile control module comprising: a zone-averaging model for extracting more-or-less-independent thickness information from a measured water profile for each of a plurality of pressure zones; a tracking error calculation and reference generator for generating a feasible feedback control error for each of said plurality of pressure zones; a multi-input multi-output pressure feedback controller for generating real-time pressure commands from said feasible feedback control error for each of said plurality of pressure zones; and a gain estimation model for adjusting the gain of said multi-input multi-output pressure feedback controller using a real-time estimation of a measured CMP system removal-rate.
Claim 20
Dependent Claim
110 words
The controller of claim 16 , wherein said tracking error calculation and reference generator provides any of: an absolute thickness control mode, wherein a reference value is an external signal specifying a desired thickness and thickness removal rate, at each point in time, wherein absolute thickness and polish rate in each zone are equal to an external reference thickness and polish rate for each zone, respectively; and a uniformity control mode, wherein a reference value is equal to measured average thickness in one of said zones at each point in time to control uniformity of said wafer by making thickness in all other zones equal to thickness in reference zones.
Claim 21
Dependent Claim
33 words
The controller of claim 11 , said motor velocity control module further comprising: a kinematic model for determining how motor velocity affects a distributed removal rate to control wafer and pad motor velocities.
Claim 22
Dependent Claim
22 words
The controller of claim 11 , wherein said controller is augmented with any of run-to-run control, iterative learning control, and adaptive control.
Claim 23
Independent Claim
102 words
A method for controlling a chemical-mechanical planarization (CMP) system, comprising the steps of: controlling average polishing pad temperature responsive to temperatures measured by any of an in-situ temperature sensor and a thermal model; controlling individual zone pressures for a multi-zone pressure CMP process to provide in-situ pressure feedback using in-situ wafer thickness measurements, as obtained with an in-situ thickness sensor, to adjust pressures in-situ; controlling slurry flow to said CMP system; controlling motor velocity; and post-scaling all control variables (pressure, slurry flow rate, velocity), wherein net temperature increase or decrease from individual control variables is counteracted by total scaling of all variables.
Claim 24
Independent Claim
102 words
A method for controlling a chemical-mechanical planarization (CMP) system, comprising the steps of: controlling average polishing pad temperature responsive to temperatures measured by any of an in-situ temperature sensor and a thermal model; controlling individual zone pressures for a multi-zone pressure CMP process to provide in-situ pressure feedback using in-situ wafer thickness measurements, as obtained with an in-situ thickness sensor, to adjust pressures in-situ; controlling slurry flow to said CMP system; controlling motor velocity; and post-scaling all control variables (pressure, slurry flow rate, velocity), wherein net temperature increase or decrease from individual control variables is counteracted by total scaling of all variables.
Claim 25
Dependent Claim
125 words
The method of claim 20 , said temperature control step comprising the steps of: defining maximum planarization achievable by said CMP system; indirectly controlling average wafer/pad temperature by actuating any of input pressures, slurry flow rate, and wafer/pad velocities; and providing a dynamic temperature model and a dynamic temperature reference model, both of which describe evolution of average wafer/pad temperature over time; wherein said dynamic temperature model describes wafer/pad temperature, is optional, and can be replaced by a temperature measurement if a temperature sensor is available; and wherein said dynamic temperature reference model describes desired or reference wafer/pad temperature and is driven by said master control loop; wherein wafer/pad temperature is predicted as a function of any of input pressures, slurry flow, and wafer/pad velocity.
Claim 26
Dependent Claim
26 words
The method of claim 20 , further comprising the step of: using a motor electrical power sensor for temperature sensing in lieu of a temperature sensor.
Claim 27
Dependent Claim
24 words
The method of claim 21 , further comprising the step of: providing a pressure slave loop comprising a feedback controller combined with feedforward control.
Claim 28
Dependent Claim
48 words
The method of claim 21 , further comprising the step of: providing any of a slurry flow and a velocity slave loop, each which is fed by set point values from said master control loop; wherein any of slurry flow and velocity are used to control wafer/pad temperature.
Claim 29
Dependent Claim
84 words
The method of claim 17 , said zone pressure control step comprising the step of: extracting more-or-less-independent thickness information from a measured wafer profile for each of a plurality of pressure zones; generating a feasible feedback control error for each of said plurality of pressure zones; generating real-time pressure commands from said feasible feedback control error for each of said plurality of pressure zones; and adjusting the overall level of said real-time pressure commands using a real-time estimation of a measured CMP system removal-rate.
Claim 30
Dependent Claim
117 words
The method of claim 25 , said feedback control error generating step producing a tracking error calculation and reference generator which provides any of: an absolute thickness control mode, wherein a reference value is an external signal specifying a desired thickness and thickness removal rate, at each point in time, wherein absolute thickness and polish rate in each zone are equal to an external reference thickness and polish rate for each zone, respectively; and a uniformity control mode, wherein a reference value is equal to measured average thickness in one of said zones at each point in time to control uniformity of said wafer by making thickness in all other zones equal to thickness in reference zones.
Claim 31
Dependent Claim
32 words
The method of claim 20 , said motor velocity control step further comprising the step of determining how motor velocity affects a distributed removal rate to control wafer and pad motor velocities.
Claim 32
Dependent Claim
25 words
The method of claim 20 , further comprising the step of: augmenting system control with any of run-to-run control, iterative learning control, and adaptive control.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 2009-05-22 | 2009-11-21 | 2010-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2013-05-22 | 2013-11-21 | 2014-05-23 | $3760.00 | Window Closed / Lapsed |
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