Effect of chelating agents on high resolution electron beam nanolithography of spin-coatable Al/sub 2/O/sub 3/ gel films

Sub-10nm lithography is a key technique in the fabrication of quantum devices. Reliable production of quantum devices requires a considerable amount of work in the field of resists. Recently we have shown that electron beam exposure studies of spin-coatable Al/sub 2/O/sub 3/ gel films prepared by reacting aluminium tri-sec-butoxide, Al(OBu/sup S/)/sub 3/, with the chelating agent (also known as /spl beta/-diketone) ethylacetoacetate (EAcAc) are not only highly sensitive when compared with sputter deposited AlO/sub x/ films but are also capable of achieving extremely small linewidths, as small as 20nm. But these films suffer from problems such as poor contrast, residue after development and instability in laboratory atmosphere. In order to improve the contrast, patterning characteristics, as well as decrease the residue, detailed studies were carried out on the gel films that were produced by reacting Al(OBu/sup S/)/sub 3/ with other chelating agents such as acetylacetone (AcAc). In this paper we present a comparative study of nanopatterning characteristics of Al/sub 2/O/sub 3/ gel films that were prepared by stabilising Al(OBu/sup S/)/sub 3/ with EAcAc (EAcAc/Al/sub 2/O/sub 3/) and AcAc (AcAc/Al/sub 2/O/sub 3/), focusing on improvement in contrast, patterning characteristics, and environmental stability.