0.25micron Lithography Using KTI 747 Negative Resist For The Trilevel Base-Layer

High resolution lithographic techniques, such as electron beam, x-ray and deep UV lithography, place stringent demand on the resist materials, process and pattern transfer technology. Multilevel resist schemes have established a niche in the microelectronics industry since the late 1970's. This technique offers advantages for submicron patterning by providing vertical walls, tight linewidth control, and excellent step coverage simultaneously. In the case of trilevel resist lithography, the thick base-layer resist planarizes the underlying device topography, reduces standing wave effects in the imaging resist, and serves as an etch mask for pattern transfer into the substrate. The thin intermediate barrier layer has high oxygen plasma etch resistance to faithfully transfer the lithographic pattern into the thick resist with minimum linewidth loss, and the top thin imaging resist allows high resolution capability.