Thomson-csf

Francoise Barre

Maryse Gazard

Armand Eranian

Jean-Claude Dubois

Jean Claude Dubois

Claude Duchesne

A family of negative resins, capable of undergoing crosslinking under the effect of more or less energetic photons (gamma radiation, X-rays, ultraviolet or visible light), applicable to the protection of objects against atmospheric agents and to the production of masks of the type used in the production of integrated circuits. The typical compound according to the invention contains at least one substance of which the chemical formula comprises a thiirane ring: ##STR1## such as 2,3-epithiopropyl methacrylate copolymerized with a vinyl monomer, such as methyl methacrylate. Crosslinking is facilitated by photoinitiators, such as aryl diazonium and aryl iodonium salts liberating Lewis acids. By selecting the photoinitiator, it is possible to act on the spectral region where irradiation is effective.

Family of compounds crosslinkable by photon irradiation

A polymerized resin capable, upon electronic irradiation, of undergoing a cross-linking completing the polymerization and rendering it insoluble in certain solvents. Such a negative resin is ten times more sensitive to electrons than the best known resin. It is obtained by copolymerization of an epithiopropylmethacrylate: ##STR1## and of a vinyl monomer such as methyl methacrylate.

Method for making electron sensitive negative resist

The present invention relates to a family of substances which, in different temperature ranges, exhibit smectic or nematic properties of mesomorphism. Their general formula is: ##STR1## where R designates one of the three radicals: ##STR2## (n being a whole number ranging from 1 to 20) and X designating a halogen (Br preferably) or the nitrile radical C N.

Mesogenic products for liquid crystal cells

The present invention relates to a family of substances which, in different temperature ranges, exhibit smectic or nematic properties of mesomorphism. Their general formula is: ##STR1## where R designates one of the three radicals:

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Paris, France

Francoise Barre