Process for determining photoresist develop time by optical transmission
AssigneeTexas Instruments Incorporated
InventorsEdwin G. Millis, Samuel J. Wood, Jr.
Life of this patent
Estimating the term…
Abstract
A reflective beam of light is used to analyze the optical transmission properties of a developer fluid during puddle develop of photoresist polymer for detercting the process endpoint.
Claims17
In a method of developing patterned photoresist polymer on a semiconductor wafer and detecting the endpoint of the develop process as determined by the transparency of the developer fluid to a beam of light, which transparency is dependent upon the amount of photoresist polymer dissolved in the developer fluid, the steps of;
- covering the semiconductor wafer with a developer fluid, reflecting a first beam of light off the surface of the developer-covered semiconductor wafer as the developer dissolves the photoresist polymer, and detecting the reflected light beam, thereby measuring the transparency of the developer fluid which is dependent upon the amount of dissolved photoresist polymer in the developer fluid.
In a method of developing patterned photoresist polymer on a semiconductor wafer and detecting the endpoint of the develop process as determined by the transparency of the developer fluid to a beam of light, which transparency is dependent upon the amount of photoresist polymer dissolved in the developer fluid, the steps of;
- spinning the semiconductor wafer on a spinner chuck while applying a developer fluid to the surface thereof, stopping the spinning of the semiconductor wafer while the developer fluid is dissolving the photoresist polymer, reflecting a first beam of light through the developer fluid off the surface of the semiconductor wafer, detecting the beam of light with a photodetector, continuously monitoring the amount of light detected by the photodetector during the time the developer is dissolving the photoresist polymer, the amount of reflected light being affected by the amount of photoresist polymer dissolved in the developer fluid, and rinsing the developer fluid from the surface of the semiconductor wafer when the amount of reflected light decreases to a predetermined amount.
Dependencies are inferred from the claim text.