The self-development characteristics of Si containing polymers were investigated with the objective of applying these polymers to the surface-imaging process in x-ray lithography. Polymers containing Si atoms in their backbones or substitutents were studied in detail; UV and Fourier transform infared spectra were used to study their reaction to soft xrays. The polymers exhibited postive-tone characteristics when exposed to x-rays. Their self-development sensitivity and oxygen reactive ion etching (02-RIE) resistance were measured to estimate the feasibility of their use in lithography. Polysilanes and polystyrene showed low self-development sensitivity while polymethacrylates showed high sensitivity. All of these polymers have 02-RIE resistance high enough for application as surface-imaging resists. The films remaining after self-development were characterized by estimating their durability against solvents, their thermal desorption spectra, and their x-ray photoelectron spectra. A polymethacrylate derivative was found to be the most promising of the polymers; it was applied to pattern replication using dry development. The results show that Si containing polymers are fundamentally feasible for the postive-tone dry processes.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.122.253.212 Downloaded on 2015-06-04 to IP
Thermal effects on positioning accuracy in an electron beam lithography system have been evaluated. In order to make 5X reticles for 0.3-µm ULSIs, positioning accuracy as small as 0.06 µm is required. Thermal effects are significant problems in achieving highly accurate reticle judging from positioning error analysis. In this study, internal thermal effects were investigated; these were (1) heating by electron beam illumination and (2) stage friction with step-and-repeat movement. As a result, the positioning error due to electron beam illumination is negligibly small compared with 0.06 µm and the stage temperature fluctuation must be controlled within 0.07°C to maintain a positioning error within 0.06 µm. Furthermore, internal thermal effects of the system could be fatal in next-generation electron beam lithography systems without improvement of materials and systems.
A very low reflectivity of the order of 10 −4 is demonstrated for dual-layer anti-reflection coatings on normal facet semiconductor lasers, by integrated in situ monitoring. The method has been tested on three and eight quantum-well InGaAsP ridge lasers that consist of a gain section and an integrated absorber section. The principle is to monitor the change in the photocurrent generated in the absorber that is proportional to the output optical intensity from the laser, which changes as the coating progresses.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.