Analysis techniques for investigation of photoresist silylation processes

In this work, the authors explore the application of tetramethylammonium hydroxide (TMAH) developer chemical as a staining agent to enhance the top-down contrast of a silylated pattern to optical detection. When examining a silylated latent image top-down, the topographical differences generated due to the swelling of the silylated region are relied upon to identify pattern details. However, for lower exposure energy or shorter silylation times, there may not be sufficient silicon incorporation to allow clear identification of specific structures for cleaving. The authors have used the TMAH staining technique proposed by La Tulipe et al. to enhance the relief top-down, thereby facilitating analysis of even mildly silylated samples. Results will be presented illustrating the contrast enhancement after staining. Cross-sections of film profiles after aqueous silylation of an I-line photoresist with a solution of hexamethylcyclotrisilazane will also be generated.