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US 6,161,054 AGranted
Cell control method and apparatus
AssigneeOn-Line Technologies, Inc.
InventorsPeter A. Rosenthal, Peter R. Solomon, Anthony S. Bonanno, William J. Eikleberry
Life of this patent
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Abstract
An implementation of sensor-driven run-to-run process control for semiconductor wafer fabrication integrates a robust, automated Fourier transform infrared reflectometer onto a wafer fabrication cluster tool. Cell controller software integrates an adaptive run-to-run controller, process tool recipe upload and download through a SECS port, sensor control, data archiving, and a graphical user interface.
Claims13
Apparatus for in-line control of a semiconductor wafer fabrication tool, comprising:
- a Fourier transform infrared reflectometer for measuring, in a fabrication tool, at least one property of each of a series of semiconductor wafers sequentially processed in the tool;
- and
- electronic data processing means operatively connected to said reflectometer for controlling the conditions of processing in the fabrication tool, said data processing means being programmed to perform the functions:
- (a) store target values for said at least one wafer property that is to be measured;
- (b) store measured values of said at least one property for a series of wafers processed in sequence in the fabrication tool;
- (c) compare said measured values to said target value to determine the existence of departures of said measured values from said target value;
- (d) analyze said departures of values to determine the existence of a trend therein, and to distinguish any such trend from normal statistical variations in the process;
- (e) relate possible changes of processing conditions in the fabrication tool to resulting changes in the wafer state properties;
- and
- (f) based upon the relationship established by said function (e), and said trend of departures of values, as so distinguished, effect such changes in processing conditions as will reduce the departure, from said target value, of said at least one property in wafers subsequently processed in the fabrication tool.
7 more elements
A system for semiconductor wafer fabrication, comprising:
- a wafer fabrication tool constructed for carrying out process operations sequentially on a series of wafers, said fabrication tool including a plurality of chambers for receiving wafers being fabricated, and means for changing the conditions of processing in at least one of said chambers of said tool;
- a Fourier transform infrared reflectometer for measuring at least one property of each of a series of semiconductor wafers sequentially processed in said fabrication tool, said reflectometer having optics for receiving spectral reflectance from wafers disposed in a chamber of said fabrication tool;
- and
- electronic data processing means operatively connected to said reflectometer for controlling the conditions of processing in said one chamber of said fabrication tool, said data processing means being programmed to perform the functions:
- (a) store target values for said at least one wafer property that is to be measured;
- (b) store measured values of said at least one property for a series of wafers processed in sequence in said fabrication tool;
- (c) compare said measured values to said target value to determine the existence of departures of said measured values from said target value;
- (d) analyze said departures of values to determine the existence of a trend therein, and to distinguish any such trend from normal statistical variations in the process;
- (e) relate possible changes of processing conditions in said one chamber of said fabrication tool to resulting changes in the wafer state properties;
- and
- (f) based upon the relationship established by said function (e), and said trend of departures of values, as so distinguished, effect such changes in processing conditions as will reduce the deviation, from said target value, of said at least one property in wafers subsequently processed in said one chamber of said fabrication tool.
8 more elements
Dependencies are inferred from the claim text.