US 7,029,808 B2 · Photosensitive coating material for a substrate and process for exposing the coated substrate

Abstract

A radiation-sensitive coating material, in addition to a base polymer, has a solvent and a radiation-active substance which forms an acid on irradiation by light (including energetic electrons or ions), a fluorescent substance which alters its fluorescence property subject to a change in the acid content of its surroundings. In a process for exposing a substrate coated with the coating material at least one sensor in the exposure chamber of the exposure apparatus measures the intensity of the change in fluorescence spectrum as a function of time during the exposure operation. From the course of intensity at the time of an individual line of the fluorescence spectrum or the intensity integrated over a wavelength interval it is possible to determine the endpoint of the exposure operation by way of electronic algorithms. Deviations from experimentally determined ideal curves of the intensity course provide information on erroneous functions in the course of coating material application and exposure.

Claims3

Dependent claims

A process for exposing a substrate in an exposure apparatus, which comprises the steps of:

providing a substrate coated with the radiation-sensitive coating material comprising:
a base polymer;
a solvent;
a radiation-active substance forming an acid upon irradiation with energetic radiation;
and
a fluorescent substance having a fluorescence property, said fluorescent substance changing a fluorescence in dependence on an acid fraction present in a material surrounding said fluorescent substance;
loading the substrate into an exposure apparatus having at least one first sensor for detecting light re-emitted by the fluorescent substance in the coating material within a first wavelength range;
starting a first exposure operation by projecting a pattern into the photosensitive layer;
firstly measuring a first intensity of light emitted by the fluorescent substance at a first point in time with the at least one first sensor;
at least once secondly measuring a second intensity of light emitted by the fluorescent substance at at least one second point in time, with the at least one first sensor;
comparing the first intensity with the second intensity;
and
ending the exposure operation in dependence on a comparison result of the comparing step.

10 more elements

A process for exposing a substrate in an exposure apparatus, which comprises the steps of:

providing a substrate coated with the photosensitive coating material comprising:
a base polymer;
a solvent;
a photoactive substance forming an acid upon irradiation with light;
and
a fluorescent substance surrounded by at least one material and having a fluorescence property, the fluorescence property of said fluorescent substance changing in dependence on an acid fraction present in said at least one material;
loading the substrate into an exposure apparatus having at least one first sensor for detecting light re-emitted by the fluorescent substance in the photosensitive coating material within a first wavelength range;
starting a first exposure operation by projecting a pattern into the photosensitive layer;
firstly measuring a first intensity of light re-emitted by the fluorescent substance at a first point in time with the at least one first sensor;
at least once secondly measuring a second intensity of light re-emitted by the fluorescent substance at at least one second point in time, with the at least one first sensor;
comparing the first intensity with the second intensity;
and
ending the exposure operation in dependence on a comparison result of the comparing step.

10 more elements

Dependencies are inferred from the claim text.

Photosensitive coating material for a substrate and process for exposing the coated substrate

Life of this patent

Photosensitive coating material for a substrate and process for exposing the coated substrate

Life of this patent

Abstract

Claims3