Extended kalman filter incorporating offline metrology
AssigneeMicron Technology, Inc.
InventorJim Hofmann
Life of this patent
Estimating the term…
Abstract
An algorithm uses offline metrology to control a process by passing information from an outer control loop to an inner control loop, extended Kalman filter estimator. The inner control loop operates online, and the outer control loop operates asynchronously with respect to the inner control loop. The online control loop is updated for each subsequent process. The offline metrology is optionally updated for each subsequent process.
Claims31
A method comprising:
- estimating a state variable for a physical process by use of an extended Kalman Filter (EKF) that operates in an online control loop;
- applying a control statement to the physical process from the online control loop;
- and
- sending an information statement from an offline metrology control loop to the online control loop, wherein the information statement optionally changes estimating the state variable.
A method of planarizing a substrate comprising:
- in an inner loop:
- estimating state variables of a substrate planarizing cycle, wherein the estimating the state variables includes use of an extended Kalman filter (EKF) engine;
- and
- estimating the endpoint of the substrate planarizing cycle based upon the estimating of the state variables;
- and
- in an outer loop:
- asynchronously comparing at least one of a state variable included in the state variables and an endpoint to an offline metrology database;
- and
- sending an information statement from the outer loop to the inner loop.
A method of controlling a process, comprising:
- estimating a state variable for a physical process by use of an extended Kalman Filter (EKF) that operates in an online control loop;
- applying a control statement to the physical process from the online control loop;
- and
- sending an information statement from an offline metrology control loop to the online control loop, wherein the information statement optionally changes estimating the state variable, wherein the sending includes initiating an interrupt of the online control loop.
A process of fabricating and assembling a microelectronic system comprising:
- processing a substrate with a two-control loop control system, wherein the two-control loop control system includes an online control loop and an offline metrology control loop;
- and
- assembling at least a portion of the substrate into an integrated microelectronic device.
A method of calculating a present condition, comprising:
- estimating a state variable for a physical process by use of an extended Kalman Filter (EKF) that operates in an online control loop;
- applying a control statement to the physical process from the online control loop;
- and
- sending an information statement from an offline metrology control loop to the online control loop, wherein the information statement is used in estimating the state variable for a next iteration of the online control loop.
Dependencies are inferred from the claim text.