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.
Claims30
A computer readable medium for executing a set of instructions, the computer readable medium comprising:
- in an inner loop:
- establishing estimates of state variables of a substrate planarizing cycle, wherein establishing includes the use of an extended Kalman filter (EKF) engine;
- and
- estimating the endpoint of the substrate planarizing cycle based upon the estimates of the state variables;
- in an outer loop:
- asynchronously comparing at least one of a state variable and an endpoint to an offline metrology database;
- and
- sending and information statement from the outer loop to the inner loop.
A computer readable medium for executing a set of instructions, the computer readable medium comprising:
- estimating state variables of a physical process by use of an extended Kalman filter (EKF) engine operating in an online control loop;
- and
- transmitting the estimated state variables to a control loop of the physical process, including at least one of an estimated endpoint of the physical process based upon the estimates of the state variables, estimated total reflectance of a substrate that includes an array and a periphery region;
- and an estimated instantaneous change in reflectance of the substrate.
A control system comprising:
- a physical interface;
- an online first, extended Kalman filter (EKF) estimator;
- an offline metrology data base that optionally uses a second EKF estimator;
- an information statement from the offline metrology data base to the first EKF estimator;
- and
- a control statement from the online EKF estimator to the physical interface.
A control system comprising:
- a chemical-mechanical polishing (CMP) interface;
- an online first, extended Kalman filter (EKF) estimator;
- an offline metrology data base that optionally uses a second EKF estimator;
- an information statement from the offline metrology data base to the first EKF estimator;
- and
- a control statement from the online EKF estimator to the CMP interface.
A control system comprising:
- a physical interface;
- an online first, extended Kalman filter (EKF) estimator;
- an offline metrology data base in communication with the online estimator;
- an information statement from the offline metrology data base to the EKF estimator;
- and
- a control statement from the online EKF estimator to the physical interface.
A control system for a cyclic process, comprising:
- an outer control loop, sending process parameter data from an nth process run, where n is an integer greater than zero, to update and improve accuracy in a process parameter;
- an inner control loop including an extended Kalman filter (EKF) receiving the process parameter data, calculating an updated process parameter and sending the updated process parameter to a process parameter controller;
- and
- the process parameter controller receiving the updated process parameter and applying the updated process parameter to the (n+m)th process run, where m is greater than one.
Dependencies are inferred from the claim text.