Organosilicon polymers for lithographic applications

Linear polymers of silicone gums (polysiloxanes) have many attributes that make them attractive for lithographic applications, such as oxidative and thermal stability, good adhesion properties, solubility in common solvents, and resistance to etching in an oxygen plasma. When polysiloxanes are used as the top imaging layer (∼2000Å) in a two‐layer resist system, the developed negative siloxane images act as a high resolution etch mask for the oxygen plasma etching of the bottom planarizing polymer layer. Commercially available polysiloxanes have been evaluated for their deep UV sensitivity at 2537Å, and have been found to have very high resolution capabilities (∼0.5μ) and high contrast (γ = 4). The negative images do not swell in the developer, and the line width is therefore independent of development time. The combination of high resolution, sensitivity, and ease of processing make this a simple multilayer system for deep UV and e‐beam applications. Copyright © 1983 Society of Plastics Engineers, Inc.