Advanced Micro Devices Corporation

Curtis Warren Doss

Richard David Edwards

Anthony John Toprac

Edward Christopher Stewart

Scott Gregory Bushman

Anastasia Lynn Oshelski Peterson

In one illustrative embodiment, a method is provided that controls a stepper to position a focal plane of a light source adjacent a top surface of a layer of photoresist. A metrology tool is used to measure a thickness of the layer of photoresist, and a controller uses the thickness measurement to determine a position of the top surface of the layer of photoresist. The controller delivers a control signal to the stepper, causing the stepper to move the focal plane of the light source adjacent the top surface of the layer of photoresist.

Method and apparatus for controlling focus based on a thickness of a layer of photoresist

In one illustrative embodiment, a method is provided that comprises energizing a light source to provide light having a preselected intensity. A first photosensor, which is capable of delivering a first signal indicative of the intensity of the light source, is exposed to the light source. A second photosensor, which is also capable of delivering a second signal indicative of the intensity of the light source, is also exposed to the light source. Thereafter, the first and second signals are compared, and an error signal is delivered in response to detecting a significant difference between the first and second signals.

Method and apparatus for controlling a stepper

Method for controlling and monitoring light source intensity

A method for detecting a degraded light source is provided. An exposure time associated with the light source is monitored. The exposure time is compared to at least one control limit. A degraded condition is identified based on the exposure time violating the control limit. A processing tool includes a stepper and an automatic process controller. The stepper has a light source and is adapted to illuminate a wafer for an exposure time. The automatic process controller is adapted to monitor the exposure time, compare the exposure time to at least one control limit, and identify a degraded condition based on the exposure time violating the control limit.

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Austin, TX, United States of America

Curtis Warren Doss