Laser-induced reactions in a deep UV resist system: Studied with picosecond infrared spectroscopy

Book · Tue Dec 31 04:00:00 EST 1996

OSTI ID:490903

Lippert, T; Koskelo, A; Stoutland, P O ^[1]

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1. Los Alamos National Lab., NM (United States). Div. of Chemical Science and Technology

One of the most technologically important uses of organic photochemistry is in the imaging industry where radiation-sensitive organic monomers and polymers are used in photoresists. The chemistry which occurs in these systems is the basis for the manufacture of high-density electronic circuits, as well as for the production of printing plates. A widely-used class of compounds for imaging applications are diazoketones; these compounds undergo a photoinduced Wolff rearrangement to form a ketene intermediate which subsequently hydrolyses to a base-soluble, carboxylic acid. Another use of organic molecules in polymer matrices is for dopant induced ablation of polymers. As part of a program to develop diagnostics for laser-driven reactions in polymer matrices, the authors have investigated the photo-induced decomposition of 5-diazo-2,2-dimethyl-1,3-dioxane-4,6-dione (5-diazo Meldrum`s acid, DM) in a PMMA matrix using picosecond infrared spectroscopy. In particular, irradiation of DM with a 60 ps 266 nm laser pulse results in immediate bleaching of the diazo infrared band (v = 2,172 cm{sup {minus}1}). Similarly, a new band appears within the instrument response at 2,161 cm{sup {minus}1} (FWHM = 29 cm{sup {minus}1}) and is stable to greater than 6 ns.; the authors assign this band to the ketene photoproduct of the Wolff rearrangement. Using deconvolution techniques they estimate a limit for its rate of formation of {tau} < 20 ps. The linear dependence of the absorbance change with the pump power (266 nm) even above the threshold of ablation suggest that material ejection take place after 6 ns.

• OSTI ID: 490903
• Report Number(s): CONF-951155--; ISBN 1-55899-300-2
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
DECOMPOSITION
DIAZO COMPOUNDS
EXPERIMENTAL DATA
INFRARED SPECTRA
KETONES
LASER RADIATION
MASKING
MATRIX MATERIALS
MICROELECTRONIC CIRCUITS
PHOTOCHEMISTRY
PHOTORESISTORS
PMMA
POLYPROPYLENE
REACTION KINETICS