Aqueous-Base Developable, Three-Component Resist Systems for Thick Resist Applications
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
In thick resist imaging with the use of photoresist systems consisting of a novolac resin and diazoquinone, the concentration of the photoactive compound must be reduced to allow penetration of the exposing UV light through the thick resist film for proper imaging. Since the photo-active compound functions as a dissolution inhibitor of the novolac matrix, the reduction of the diazoquinone concentration to decrease the UV absorption results in decreased sensitivity and increased dissolution rates of the unexposed areas. In consequence, when the resist film becomes very thick, a scheme that increases the resist contrast may have to be incorporated in the process, which further reduces the resist sensitivity.