Patent attributes
A method of lithography is disclosed, which allows for independent resist process optimization of two or more exposure steps that are performed on a single resist layer. By providing for a separate post-exposure bake after each resist exposure step, pattern resolution for each exposure can be optimized. The method can generally be used with different lithographic techniques, and is well-suited for hybrid lithography. It has been applied to the fabrication of a device, in which the active area and the gate levels are defined in separate mask levels using hybrid lithography with an e-beam source and a 248 nm source respectively. Conditions for post-exposure bakes after the two exposure steps are independently adjusted to provide for optimized results.
