The patent's assignee for patent number 8643823 is Media Lario S.R.L. (Bosisio Parini (LC), IT).
News editors obtained the following quote from the background information supplied by the inventors: "EUV lithography is anticipated to be the lithographic process of choice for producing future generations of semiconductor devices having linewidths on the order of 32 nm and smaller. The wavelength of the EUV radiation is nominally 13.5 nm, which calls for the use of specialized optics to collect and image the EUV radiation.
"One type of EUV optical system used to collect the radiation from the light source is a grazing incidence collector (GIC). Another type is a constant-incidence collector (CIC). A GIC typically comprises one or more concentrically arranged shells configured to receive light from the EUV source at grazing incidence and reflect the light to form a focused illumination beam that first forms an intermediate focus and then creates an illumination region in the far field. The far-field illumination region is preferably uniform to within a specification set by the overall system optical design.
"The light sources being considered for EUV lithography include a discharge-produced plasma (DPP) and laser-produced plasma (LPP). The conversion efficiency of these sources is only a few percent, with most of the energy used to generate the EUV radiation converted to infrared, visible and UV radiation and energetic particles that can be incident upon the collector mirror. This radiation causes a substantial thermal load on the GIC mirror. Each GIC mirror shell therefore needs to be cooled so that the heat absorbed by the mirror does not substantially adversely affect GIC mirror performance or damage the GIC mirror.
"The same radiation can also heat the spider that holds the GIC shells in a fixed relation to one another. Accordingly, the spider is also preferably cooled so that heat absorbed by the spider is not transferred to the GIC shells, and so that the spider itself does not change its shape. Thus, the GIC mirror is actually part of a GIC mirror system that also includes a GIC shell cooling system and that may also include a spider cooling system.
"Essentially all GIC mirror systems for EUV lithography have been used to date only in the laboratory or for experimental 'alpha' systems under very controlled conditions. As such, there has been little effort directed to GIC shell cooling systems and spider cooling systems for use in a commercially viable EUV lithography system. In fact, the increasing demand for higher EUV power promises an increased thermal load on the GIC mirror, making such thermal management even more important.
"Consequently, more efficient and effective thermal management and cooling systems must be implemented to minimize the potential for optical distortion of the GIC mirror due to the thermal load. The need for thermal management requires a GIC mirror system that is relatively complicated to fabricate. In particular, the GIC mirror needs to be interfaced with the GIC shell cooling system and the optional spider cooling system without causing mechanical distortion of the GIC shells of the GIC mirror."
As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "Aspects of the invention include stress-decoupling devices for and methods of using such devices in a cooled mirror system such as a cooled GIC mirror system that includes cooled GIC shells supported by a spider, which may also be cooled.
"An example method of the invention includes providing a cooled GIC shell, providing input and output primary cooling-fluid manifolds, and fluidly connecting the cooled GIC shell to the input and output primary cooling-fluid manifolds through respective stress-decoupling devices. An example stress-decoupling device includes inner and outer bellows that define a sealed cavity filled with a gas. An expansion-limiting member limits the expansion of the inner bellows due to the pressure of the cooling fluid flowing therethrough. The stress-decoupling device is configured and disposed to reduce or prevent the communication of stress from parts of the GIC mirror system to the GIC shells and can be arranged anywhere in the GIC mirror system to accomplish this function. More than one stress-decoupling device may be included in a given fluid-conducting member. Exemplary locations include within or at one or both ends of fluid-conducting members (e.g., 'feeder lines') that connect cooling lines or cooling channels to a cooling fluid manifold.
"It is to be understood that both the foregoing general description and the following detailed description present embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operations of the invention."
For additional information on this patent, see: Bianucci, Giovanni; Moretti, Stefano; Yue, Gordon; Cassol, Gian Luca. Stress-Decoupling Devices and Methods for Cooled Mirror Systems. U.S. Patent Number 8643823, filed
Keywords for this news article include: Media Lario S.R.L.
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC
Most Popular Stories
- Dmytro Firtash, Ukrainian Billionaire, Arrested in Vienna
- Obama, Ukraine Discuss Russian Incursion in Crimea
- Obama's Overtime Initiative Praised, Condemned
- Republicans Warn Obama on Immigration
- Liberty Media Drops Sirius Bid
- West Readies Harsh Sanctions Against Russia
- Drake Wins Big MTV's Woodie Awards at SXSW
- Uli Hoeness, Bayern Munich President, Gets Prison for Tax Evasion
- Lady Gaga Roasts Self on Spit at SXSW
- Calumet Photo Files for Bankruptcy