Effects of developing conditions on the contrast and sensitivity of hydrogen silsesquioxane

The effects of developing conditions on the lithography properties of hydrogen silsesquioxane (HSQ) have been investigated, using the contrast curve as a characterisation tool. Particularly, both the contrast and the curing dose of the HSQ as the function of the developing temperature have been measured. It was discovered that increasing the developing temperature could improve not only the resist contrast, but also the efficient removal of residues between the exposed features. The development processes of the HSQ with and without the assistance of ultrasonic agitation were compared, showing that the ultrasonic agitation does help to remove a thin layer of residual resist. However, the time delay up to four months after the electron beam exposure and before development did not show significant difference in the lithography result. It is concluded that high resolution and highly dense HSQ patterns with high aspect ratio can be achieved by a hot developing technique. (c) 2006 Elsevier B.V. All rights reserved.