US 7,116,405 B2 · Maskless, microlens EUV lithography system with grazing-incidence illumination optics

Abstract

An EUV lithography system achieves high-resolution printing without the use of photomasks, projection optics, multilayer mirrors, or an extremely high-power EUV source. The system comprises a xenon laser-produced-plasma (LPP) illumination source (requiring 93 W hemispherical EUV emission in the wavelength range 10–12 nm), all-ruthenium optics (grazing-incidence mirrors and microlenses) and spatial light modulators comprising MEMS-actuated microshutters. Two 300-mm wafers are simultaneously exposed with a single 10 kHz LPP source to achieve a throughput of 6 wafers per hour, per LPP source. The illumination is focused by the microlens arrays onto diffraction-limited (42-nm FWHM) spots on the wafer plane, and the spots are intensity-modulated by the microshutters as they are raster-scanned across the wafer surface to create a digitally synthesized exposure image. The optical path between the source and the microlenses traverses seven grazing-incidence mirrors (two collimator elements and five fold mirrors), which have high reflection efficiency and essentially unlimited wavelength bandpass.

Claims29

Dependent claims

A printing exposure apparatus comprising a radiation source, illumination optics, a modulator mechanism, a microlens array, and a scanning mechanism, wherein:

the illumination optics convey radiation from the radiation source to the microlens array;
the microlens array focuses the radiation onto a corresponding array of focal points on a printing surface;
the modulator mechanism modulates the radiation, whereby the focal points' exposure intensity levels are controllably varied;
the scanning mechanism establishes relative motion between the printing surface and the microlens array in synchronization with the modulator mechanism as the printing surface is exposed, whereby a synthesized, high-resolution exposure image is formed on the printing surface;
and
the illumination optics consist of grazing-incidence mirrors.

3 more elements

A printing exposure apparatus comprising:

a radiation source;
a plurality of microlens arrays, at least one of the microlenses in at least one of the microlens arrays being a multistage lens;
illumination optics that convey radiation from the radiation source to the microlens arrays, the illumination optics and the microlens arrays being configured to focus the radiation from the radiation source on a corresponding plurality of focal point arrays on a printing surface;
a modulator mechanism disposed between the radiation source and the printing surface that modulates the radiation, whereby the focal points' exposure intensity levels are controllably varied;
and
a scanning mechanism that establishes relative motion between the printing surface and the microlens arrays in synchronization with the modulator mechanism as the printing surface is exposed, whereby a synthesized, high-resolution exposure image is formed on the printing surface;
the illumination optics consisting of
collection optics consisting of at least one grazing-incidence mirror, the collection optics being configured to collect radiation from the radiation source, and
distribution optics consisting of at least one grazing-incidence mirror, the distribution optics being configured to partition radiation from the collection optics and distribute the radiation onto the plurality of microlens arrays.

6 more elements

Dependencies are inferred from the claim text.

Maskless, microlens EUV lithography system with grazing-incidence illumination optics

Life of this patent

Maskless, microlens EUV lithography system with grazing-incidence illumination optics

Life of this patent

Abstract

Claims29