Thin film transistors (TFTs) fabricated by solution processing of sol-gel oxide semiconductor precursors in the group In-Ga-Zn are described. The TFT mobility varies over a wide range depending on the precursor materials, the composition, and the processing variables, with the highest mobility being about 30 cm(2)/(V s) for IZO and 20 cm(2)/(V s) for IGZO. The positive dark bias stress effect decreases markedly as the mobility increases and the high mobility devices are quite stable. The negative bias illumination stress effect is also weaker in the higher mobility TFTs, and some different characteristic properties are observed. The TFT mobility, threshold voltage, and bias stress properties are discussed in terms of the formation of self-compensated donor and acceptor states, based on the chemistry and thermodynamics of the sol-gel process.

Many semiconductor device manufacturers plan to make products with 157 nm lithography beginning in 2004. There is, at this time, no functional photoresist suitable for 157 nm exposure. Developing resist materials for 157 nm lithography is particularly challenging since water, oxygen, and even polyethylene are strongly absorbing at this wavelength. A modular approach to the design of a single layer resist for 157 nm has been undertaken. In this approach, the resist has been conceptually segmented into four functional modules: an acidic group, an acid labile protecting group, an etch resistant moiety, and a polymer backbone. Each of these modules has an assigned function and each must be transparent at 157 nm. Progress has been made toward finding candidate structures for each of these modules. We have demonstrated that acidic bistrifluoromethylcarbinols are very transparent at 157 nm and function efficiently in chemically amplified resists with both high and low activation energy protecting groups. Judicious incorporation of fluorine in acrylates and alicyclics has provided etch resistant polymers with greatly improved transparency at 157 nm. In particular, esters of poly͑␣-trifluromethylacrylic acid͒ are far more transparent than their protio analogs. The Diels-Alder adducts derived from reaction of these and other fluorinated alkenes with cyclopentadiene offer a route to a wide range of alicyclic monomers that show great promise as transparent, etch resistant platforms for the design of 157 nm resists. Polymers of this sort with absorbance below 2 per micrometer are reported.

This paper reports our work on a series of alicyclic polymer-based photoresist platforms designed for 193 nm lithography. The polymers described here were prepared from derivatives of norbornene and appropriate co-monomers by either free radical or ring opening metathesis polymerization methods. A variety of techniques were explored as a means of enhancing the lithographic, optical, dissolution, and mechanical properties of photoresists formulated from these alicyclic polymers. Recent studies designed to improve the lithographic performance of photoresists formulated with these materials are described.absorbance at 193 nm. Therefore, in 1993 our group began an investigation of norbornene-derived amorphous polyolefins for potential use in 193 nm photoresist formulations. 0277-786X/981$1O.oo SPIE Vol. 3333 / 425 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 05/16/2015 Terms of Use: http://spiedl.org/terms SPIE Vol. 3333 / 427 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 05/16/2015 Terms of Use: http://spiedl.org/terms

This paper reports our work on a series of alicyclic polymer-based photoresist platforms designed for 193 nm lithography. The polymers described here were prepared from derivatives of norbornene and appropriate co-monomers by free radical polymerization. A variety of techniques were explored as a means of enhancing the lithographic, optical, dissolution, and mechanical properties of photoresists formulated from these alicyclic polymers. Recent studies designed to improve the lithographic performance of photoresists formulated with these materials are described. The process lattitude, delay stability and the utility of the resist for pattern transfer of lithographic images into polysilicon were also studied.

This paper reports work toward designing environmentally stable alicyclic polymerbased photoresists for ArF excimer laser lithography. A design concept for improving postexposure delay stability is suggested in this paper. The polymers described here were prepared from dinorbornene derivatives and maleic anhydride by free radical polymerization. The relationship among polymer structure, glass transition temperature (Tg) and post-exposure delay stability was studied. This new polymer design offers a pathway towards good post-exposure delay stability while maintaining high resolution.