Hybrid bilayer imaging approach using single component metal-organic precursors for high-resolution electron beam lithography

Autor: Clifford L. Henderson, Augustin Jeyakumar, Seigi Suh, Paul J. Roman
Rok vydání: 2003
Předmět:
Zdroj: Advances in Resist Technology and Processing XX.
ISSN: 0277-786X
DOI: 10.1117/12.485133
Popis: A hybrid bilayer imaging approach has been developed which uses a thin radiation sensitive, single component, metal-organic precursor film in conjunction with a thicker organic planarizing etch barrier. Upon electron beam irradiation, the metal-organic precursors are converted to a metal-oxide etch mask and the pattern can be transferred through the organic etch barrier layer using an oxygen reactive ion etch. These novel precursors can also be converted to the metal-oxide using deep ultraviolet optical irradiation or thermal baking. Therefore, a combination of blanket conversion steps followed by the patterning process can be utilized in order to reduce imaging doses. In this work, results of characterizing a titanium(n-butoxide)2(2-ethylhexanoate)2 precursor are presented due to its combined properties of hydrolytic stability and moderate sensitivity. It was found that using a blanket thermal bake step of 1, 2, and 3 minutes at 150°C prior to electron beam exposure increased the sensitivity of the materials to 200, 90, and 72 µC/cm2 respectively. However, the contrast of the material decreased from 4.40 to 2.17 as a consequence of pre-exposure thermal baking. The etching characteristics of the metal-organic precursor were also studied in ashing and silicon dioxide etching plasmas. It was found that the etch rate in the different plasmas depends strongly on the extent of conversion of the metal-organic film. Films with higher extents of conversion to the metal-oxide provide higher etch resistance in general. The patterning capability with these metal-organic precursors is demonstrated on top of both silicon substrates and hard baked novolac films.
Databáze: OpenAIRE