Disturbance-free, recipe-controlled plasma processing system and method

• US 20030003607A1
• Filed: 09/06/2001
• Published: 01/02/2003
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tanaka, Junichi, Morioka, Natsuyo, Ikuhara, Shoji, Yamamoto, Hideyuki, Kitsunai, Hiroyuki, Tamaki, Kenji, Masuda, Toshio, Kagoshima, Akira
• Granted Patent: US 6,733,618 B2
• Time in Patent Office: Days
• US Class Current: 438/14
• CPC Class Codes: G05B 19/41875 characterised by quality surveillance of production
• CPC Class Codes: G05B 2219/45031 Manufacturing semiconductor wafers
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A plasma processing control system and method which can suppress influences caused by disturbances. The control system includes a plasma processor for performing processing operation over a sample accommodated within a vacuum processing chamber, a sensor for monitoring process parameters during processing operation of the plasma processor, a processed-result estimation model for estimating a processed result on the basis of a monitored output of the sensor and a preset processed-result prediction equation, and an optimum recipe calculation model for calculating correction values of processing conditions on the basis of an estimated result of the processed-result estimation model in such a manner that the processed result becomes a target value. The plasma processor is controlled on the basis of a recipe generated by the optimum recipe calculation model.

Claims

1. A plasma processing control system comprising:

a plasma processor for performing plasma processing operation over a sample accommodated within a vacuum processing chamber;

a sensor for monitoring process parameters during processing operation of the processor;

means for providing a processing-result estimation model to estimate a processed result on the basis of a monitored output from the sensor and a preset processed-result estimation equation;

means for providing an optimum recipe calculation model which calculates optimum processing conditions such that the processed result becomes a target value on the basis of the estimated result of the processed-result estimation model; and

a controller for controlling the plasma processing system on the basis of a recipe generated from said optimum recipe calculation model.

2. A plasma processing control system as set forth in claim 1, wherein said plasma processor includes a processed result measuring instrument for measuring a shape of said sample obtained as a result of the processing, and said measuring instrument corrects said processed-result estimation model on the basis of the measured result of the instrument.

3. A plasma processing control system as set forth in claim 1, wherein said optimum recipe calculation model providing means includes means for judging validity of an optimum recipe calculated by the model and selecting a usable recipe.

4. A plasma processing control system as set forth in claim 3, wherein said usable recipe selecting means selects one of previously-stored recipes which is the closest to the optimum recipe calculated by said optimum recipe calculation model.

5. A plasma processing control system as set forth in claim 1, wherein said optimum recipe calculation model providing means includes an instrument for measuring a shape of said sample before the processing, and said measuring instrument applies feedforward control to optimum recipe calculating operation on the basis of a measured result of the instrument with use of said optimum recipe calculation model to calculate processing conditions such that the processed result becomes a target value.

8. A plasma processing control system as set forth in claim 1, further comprising shape estimating means of a scatterometer type for estimating a processed result.

9. A plasma processing control system as set forth in claim 1, wherein said plasma processor is a plasma etcher.

13. A plasma processing control system as set forth in claim 1, wherein processing conditions of a plurality of items are previously divided into two of processing conditions which influence uniformity of the processed result in a wafer surface and processing conditions which do not influence the uniformity, only the processing conditions which do not influence the uniformity are controllably used so that the processed result coincides with the target value.

15. A plasma processing control system as set forth in claim 8, wherein said shape estimating means of a scatterometer type is used to measure a processed shape of grating marks of a wafer sampled for each lot on a non-destructive basis and to correct said processed-result estimation model.

6. A plasma processing control system comprising:

a plasma processor for performing plasma processing operation over a sample accommodated within a vacuum processing chamber;

optimum-recipe calculation model providing means for calculating an optimum recipe on the basis of a measured result of a processed result measuring instrument and a target value;

usable recipe selecting means for judging validity of the optimum recipe calculated by said optimum recipe calculation model and selecting a usable recipe; and

a controller for controlling said plasma processor on the basis of the recipe selected by said usable recipe selecting means.

7. A plasma processing control system as set forth in claim 6, wherein said optimum-recipe calculation model providing means includes an instrument for measuring a shape of said sample before the processing, and means for applying feedforward control to optimum recipe calculating operation to calculate processing conditions on the basis of the measured result of said instrument and with use of said optimum recipe calculation model such that a processed result becomes the target value.

10. A plasma processing control method for controlling a plasma processing apparatus performing plasma processing to a sample accommodated within a vacuum processing chamber of the processing apparatus, comprising the steps of:

monitoring process parameters during the processing operation for the sample;

estimating a processed result on the basis of a result of said monitoring step;

calculating correction values of processing conditions and generating an optimum recipe on the basis of an estimated result of said estimating step such that the processed result becomes a target value; and

controlling the plasma processing apparatus on the basis of said generated optimum recipe.

11. A plasma processing control method as set forth in claim 10, wherein said step of estimating a processed result on the basis of a result of said monitoring step includes an estimation model and also includes a step of correcting said estimation model on the basis of a measured result of a shape of said sample.

14. A plasma processing control method as set forth in claim 10, further comprising the steps of:

previously dividing processing conditions of a plurality of items into two of processing conditions which influence uniformity of a processed result in a wafer surface and processing conditions which do not influence the uniformity; and

optimizing the processing conditions which influence the uniformity from the viewpoint of uniformity,

and wherein said step of generating an optimum recipe includes a step of calculating and correcting correction values of only the processing conditions which do not influence the uniformity in such a manner that the processed result coincides with the target value, combining with the previously-optimized processing conditions which influence the uniformity, and generating an optimum recipe.

12. A plasma processing control method for controlling plasma processing operation performed to a sample accommodated within a vacuum processing chamber, comprising the steps of:

generating an optimum recipe on the basis of a measured result of a processed result measuring instrument;

judging validity of said optimum recipe; and

controlling the plasma processing operation on the basis of the recipe judged as having the validity.