Abstract: An integration system for obtaining a set of overlay offset parameters of a first process layer which is going to be formed in an assigned photolithography tool with an assigned mask and an assigned pre-tool. By using the integration system, the set of overlay offset parameters of the first process layer can be precisely predicted based on summing the historic-recorded set of overlay offset parameters and the bias values including a mask bias value, a photolithography tool bias value and a pit-tool bias value. Therefore, the overlay offset parameters corresponding to the same process layer can be well integrated and managed. Hence, the cost and time due to performing the test run can be saved and the throughput can be increased as well.

Abstract: An integration system for obtaining a set of overlay offset parameters of a first process layer which is going to be formed in an assigned photolithography tool with an assigned mask and an assigned pre-tool. By using the integration system, the set of overlay offset parameters of the first process layer can be precisely predicted based on summing the historic-recoded set of overlay offset parameters and the bias values including a mask bias value, a photolithography tool bias value and a pre-tool bias value. Therefore, the overlay offset parameters corresponding to the same process layer can be well integrated and managed. Hence, the cost and time due to performing the test run can be saved and the throughput can be increased as well.

Abstract: A method of coating photoresist is provided. A wafer is first provided and a spouting site is set up in a location within the circumference of the wafer. The spouting site is disposed at a distance from the center of the wafer. Next, the wafer is spun and a solvent is simultaneously dispensed on the spouting site. After that, photoresist agent is dispensed to the center of a wafer through a spout and then the photoresist agent and the solvent are spun around to spread out. Because a ring of solvent is dispensed on the wafer before spouting photoresist agent at the center of the wafer, the photoresist agent will be diluted when the photoresist agent and the solvent are being spread out. As a result, the layer of photoresist outside the original circle of solvent is thinner than the layer of photoresist inside the circle.