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Article: Optical CD metrology provides sub-nanometer accuracy.(Inspection, Measurement and Test)(Critical dimension )
- Article from:
- Semiconductor International
- Article date:
- April 1, 2004
- Author:
CopyrightCOPYRIGHT 2004 Reed Business Information. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Critical dimension (CD) control in the lithography and etch process modules at 90 nm and below is a problem confronting device makers. Traditional metrology methods that obtain only one parameter--such as linewidth--are no longer effective for controlling shrinking process windows. Cross-sectional profile information has now become necessary to accomplish effective yield control.
Control challenges at both poly gate and STI have provided a an impetus for the adoption of optical CD metrology technology. On poly gate after develop inspection (ADI) layers, for example, device makers are increasingly interested in metrology parameters such as CD at the resist bottom, ...