Method of obtaining a performance parameter for an ion implanter and an ion implanter employing the method
AssigneeApplied Materials, Inc.
InventorsJonathon Yancey Simmons, David Eugene Aberle, Biagio Gallo
Life of this patent
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Abstract
A performance parameter for an ion implanter is obtained by monitoring vacuum pressure in a vacuum chamber of the implanter to identify pulses of said pressure caused by outgassing from the wafer surfaces during respective scans or groups of scans of the wafer through the ion beam. The pressure values are integrated during the identified pulses to provide a series of pulse pressure integral values which provide the performance parameter. An increase in the integral values indicates deterioration in vacuum system performance.
Claims14
A method of obtaining performance parameter for an ion implanter of the kind which operates by effecting repeated relative scanning of an ion beam over at least one wafer to be implanted to complete an implant cycle, comprising:
- a) monitoring vacuum pressure in a vacuum chamber of the implanter to identify pulses of said pressure caused by outgassing from the wafer surface during respective scans or groups of scans of said repeated scanning, and
- b) integrating pressure values during said identified pulses to provide pulse pressure integral values for respective said pulses, said integral values providing said performance parameter.
An ion implanter comprising:
- a vacuum enclosure,
- an ion beam generator for generating in the vacuum enclosure a beam of ions for implantation,
- a holder for holding at least one wafer to be implanted,
- a scanner to effect repeated relative scanning of the ion beam over said at least one wafer to complete an implant cycle, whereby each respective scan or each of a group of said scans of said beam over said at least one wafer can cause a corresponding burst of outgassing from the wafer surface,
- a vacuum pressure detector providing electrical signals indicative of vacuum pressure in the vacuum enclosure,
- a vacuum pressure monitor responsive to said electrical signals to identify pulses of said pressure caused by said bursts of outgassing,
- an integrator to integrate each of said pressure pulses to provide respective pulse pressure integral values, and
- an implant performance monitoring system receiving said pulse pressure integral values as a performance parameter.
Dependencies are inferred from the claim text.