High-speed electron beam inspection
AssigneeKLA-Tencor Technologies Corporation
InventorsDavid L. Adler, Mark A. McCord, Mehdi Vaez-Iravani, Liqun Han, Kirk J. Bertsche
Life of this patent
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Abstract
One embodiment disclosed relates to an electron beam apparatus for inspection of a semiconductor wafer, wherein substantially an entire area of the wafer surface is scanned without moving the stage. A cathode ray tube (CRT) gun may be used to rapidly (and cost effectively) scan the beam over the wafer. Another embodiment disclosed relates to a high-speed automated e-beam inspector configured to scan the e-beam in one dimension while translating the wafer in a perpendicular direction. The translation may be linear, or alternatively, may be in a spiral path. Other embodiments are also disclosed.
Claims16
An electron beam apparatus for inspection or metrology of a semiconductor wafer, the apparatus comprising:
- an electron gun configured to generate an electron beam;
- a scanning mechanism configured to scan the electron beam over a surface of the wafer;
- a stage for holding the wafer;
- a scattered electron detector configured to detect scattered electrons generated by impingement of the electron beam onto the wafer surface;
- and
- a substrate current monitor configured to detect an electrical current from the wafer,
- wherein substantially an entire surface of the wafer is scanned without moving the stage,
- wherein the electron gun comprises a high-current source.
A method for automated inspection of a semiconductor wafer using an electron beam, the method comprising:
- using a cathode ray tube gun to generate an electron beam and to scan the electron beam over an entire surface of the wafer;
- using a stationary stage during the scanning of the wafer surface;
- and
- generating a map of wafer properties from a combination of a secondary electron current signal and a substrate current signal.
An electron beam apparatus for high-speed inspection of a semiconductor wafer, the apparatus comprising:
- an electron gun configured to generate an incident electron beam;
- a scanning deflector configured to scan the incident electron beam in one dimension;
- a stage configured to hold the wafer and to rotate the wafer in a direction that is perpendicular to the dimension of the scanning;
- a mechanism for translation of the stage while the wafer is being rotated;
- a mechanism for directing scattered electrons away from the incident electron beam and to a detector;
- and
- an electrode plate configured between the wafer and the mechanism for directing scattered electrons away from the incident electron beam,
- wherein the electrode plate has an opening aligned with the scanning dimension through which the incident beam passes.
An electron beam apparatus for high-speed inspection of a semiconductor wafer, the apparatus comprising:
- an electron gun configured to generate an incident electron beam;
- a scanning deflector configured to scan the incident electron beam in one dimension;
- and
- a stage configured to hold the wafer and to rotate the wafer in a direction that is perpendicular to the dimension of the scanning;
- and
- a mechanism for translation of the stage while the wafer is being rotated.
A method for high-speed electron-beam inspection of a semiconductor wafer, the method comprising:
- generating an incident electron beam;
- scanning the incident electron beam in one dimension;
- rotating the wafer in a direction that is perpendicular to the dimension of the scanning;
- translating the stage while the wafer is being rotated;
- and
- directing scattered electrons away from the incident electron beam and to a detector.
Dependencies are inferred from the claim text.