Method and device for lithography by extreme ultraviolet radiation
US7480030B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 2004 |
| Grant date | Jan 20, 2009 |
| Priority date | — |
| Expiry date | Dec 2, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70558
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention relates to a method and device for photolithography by extreme ultraviolet radiation, using a source resulting from the excitation of plasma by several lasers. The object which is to be photoengraved is displaced behind an irradiation window. The radiation is comprised of N successive current impulses whose surface energy is measured. In particular, each laser emits a quantum of energy having a given duration at each outset. The surface energy of the radiation received by the object in the course of the last N−1 pulses is thus added up for an nth iteration of an iterative method. The photosensitive object is displaced from a distance equal to a fraction 1/N of the width of the irradiation window according to the axis of said translation. The above-mentioned sum is subtracted from the amount of total energy required for the photoengraving method. The remaining amount of energy to be provided in order to achieve the total amount of energy and from there, the remaining pulse quanta number to be produced for an nth pulse is determined by selecting more particularly the corresponding number of laser sources to be turned on. The lasers thus selected are then triggered in or…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.