USP_6815359 (1063533), страница 2
Текст из файла (страница 2)
For 193 nm lithography, 193 nm photoresist materialsA certain amount of photoresist material (e.g., verticaland US. application Ser. No. 09/819,343 by Gabriel et al.,FACILITATE LATERAL TRIMMING,” and all assigned tophotoresist materials are typically based on phenolic polybased on acrylite and/or alicyclic polymers may be providedFOR REDUCING THE CRITICAL DIMENSIONS OFINTEGRATED CIRCUIT DEVICE FEATURES;” US.application Ser.
No. 09/819,342, by Shields et al., ?led Mar.28, 2001, entitled “PROCESS FOR FORMING SUBopaque at the shorter Wavelengths and the necessary photochemical change Will not occur throughout the entirethickness of the photoresist material.To overcome this draWback, a thinner layer of photoresistmaterial is used for the shorter lithographic Wavelengths. Astandard or conventional thickness of photoresist materialAnother exemplary embodiment relates to an integratedcircuit fabrication process. The process includes patterninga feature on a photoresist layer disposed over a substrate.55The feature is patterned in accordance With a pattern prorial can de?ne isolation regions, transistor gates, or othertransistor structures and elements.vided on a mask or reticle and a radiation at a deepPresently, lithography systems are typically con?gured toThe process further includes developing the photoresistlayer, and exposing the photoresist layer to a plasma.
Theprocess still further includes transforming the top surfaceultraviolet or extreme ultraviolet lithographic Wavelength.expose the photoresist material at a radiation having aWavelength of 248 nanometersHoWever, because theresolution of features is, in part, proportional to the inverseof the exposure Wavelength, it is desirable to pattern pho60and the side surfaces to form a hardened surface, and etchingthe substrate in accordance With the transformed feature.The patterned photoresist layer includes at least one featuretoresist material using radiation at shorter exposure Wavelengths (e.g., 193 nm, 157 nm, 126 nm, or 13.4 nm).Unfortunately, materials, equipment, and/or fabricationtechniques suitable for 248 nm lithography do not providesimilar results at the shorter exposure Wavelengths.65having a top surface and side surfaces. The exposing stepoccurs after the developing step and before the etching step.An etch stability of the feature is a function of the hardenedsurface.US 6,815,359 B234Still another exemplary embodiment relates to a featurepatterned on a photoresist layer disposed over a semicona silicon nitride layer or a metal layer.
The hard mask layercan serve as a patterned layer for processing substrate 26 orductor substrate. The feature includes exposed surfaces, andan untreated region enclosed by the exposed surfaces. Theexposed surfaces are structurally denser than the untreatedfor processing a layer upon substrate 26. In yet anotherregion due to at least one of a ?uorination, an ionfashion, and can each comprise a conductive,semiconductive, or insulative material.Photoresist layer 30 can comprise a variety of photoresistembodiment,Substrate 26 andlayerlayer28 is28anareanti-re?ectivenot describedcoatingin a limitingimplantation, and an electron beam curing.
The feature islithographically patterned using at least one of a deepultraviolet lithographic Wavelength, a vacuum ultravioletlithographic Wavelength, and an extreme ultraviolet lithographic Wavelength or has a vertical thickness less than10approximately 0.25 pm.include, among others, a matrix material or resin, a sensitiZeror inhibitor, and a solvent. Photoresist layer 30 is preferablyBRIEF DESCRIPTION OF THE DRAWINGSThe exemplary embodiments Will become more fullyunderstood from the folloWing detailed description, taken in15conjunction With the accompanying draWings, Wherein likereference numerals denote like elements, in Which:FIG. 1 is a general schematic block diagram of a lithographic system for patterning a Wafer in accordance With ana chemically ampli?ed, positive or negative tone, organicbased photoresist.
Photoresist layer 30 may be, but is notlimited to, an acrylate-based polymer, an alicyclic-basedpolymer, or a phenolic-based polymer. For example, photoresist layer 30 may comprise PAR700 photoresist manufactured by Sumitomo Chemical Company.Photoresist layer 30 is deposited, for example, by spincoating over layer 28. The thickness of photoresist layer 30exemplary embodiment;is con?gured for use in vacuum ultraviolet lithography, deepFIG. 2 is a How diagram shoWing a process for increasingthe etch stability of the photoresist layer in accordance Withan exemplary embodiment;chemicals suitable for lithographic applications. Photoresistlayer 30 is selected to have photochemical reactions inresponse to electromagnetic radiation emitted from lightsource 14.
Materials comprising photoresist layer 30 canultraviolet lithography, and/or extreme ultraviolet lithogra25FIG. 3 is a cross-sectional vieW of the Wafer, shoWing aphy (e.g., 193 nm, 157 nm, 126 nm, or 13.4 nm lithographyWavelength). Photoresist layer 30 is preferably provided ata thickness of approximately 0.25 pm or less, hereinafterdevelopment step;also referred to as a ultra-thin photoresist.Chamber 12 of lithographic system 10 can be a vacuumor loW pressure chamber for use in vacuum ultravioletFIG. 4 is a cross-sectional vieW of the Wafer illustrated inFIG. 3, shoWing a ?uorination step; andFIG. 5 is a cross-sectional vieW of the Wafer illustrated in(VUV) lithography.
Chamber 12 can contain any of numerous types of atmospheres, such as, nitrogen, etc.FIG. 4, shoWing an etch step.Alternatively, lithographic system 10 can be utiliZed inDETAILED DESCRIPTION OF THEEXEMPLARY EMBODIMENTSvarious other types of lithography including lithography that35Referring to FIG. 1, there is shoWn a Wafer 24 in auses electromagnetic radiation at any number of Wavelengths.Light source 14 provides light or electromagnetic radiation through condenser lens assembly 16, mask or reticle 18,lithographic system 10.
Lithographic system 10 includes achamber 12, a light source 14, a condenser lens assembly 16,a mask or a reticle 18, an objective lens assembly 20, and aand objective lens assembly to photoresist layer 30. Lightstage 22. Lithographic system 10 is con?gured to transfer asource 14 is an excimer laser, in one embodiment, having aWavelength of 193 nm, 157 nm, or 126 nm, or a soft x-raysource at a Wavelength of 13.4 nm.
Alternatively, lightsource 14 may be a variety of other light sources capable of40pattern or image provided on mask or reticle 18 to Wafer 24.Lithographic system 10 may be a lithographic camera orstepper unit. For example, lithographic system 10 may be aPAS 5500/900 series machine manufactured by ASML, amicroscan DUV system manufactured by Silicon Valleyemitting radiation having a Wavelength in the ultraviolet45Group, or an XLS family microlithography system manu(UV), vacuum ultraviolet (VUV), deep ultraviolet (DUV),extreme ultraviolet (EUV), or x-ray range.factured by Integrated Solutions, Inc.
of Korea.Assemblies 16 and 20 include lenses, mirrors,Wafer 24 includes a substrate 26, a layer 28, and acollimators, beam splitters, and/or other optical componentsphotoresist layer 30. Photoresist layer 24 is disposed overlayer 28, and layer 28 is disposed over substrate 26. Waferto suitably focus and direct a pattern of radiation (i.e.,radiation from light source 14 as modi?ed by a pattern or24 can be an entire integrated circuit (IC) Wafer or a part ofimage provided on mask or reticle 18) onto photoresist layeran IC Wafer. Wafer 24 can be a part of an IC, such as, a30. Stage 22 supports Wafer 24 and can move Wafer 24memory, a processing unit, an input/output device, etc.relative to assembly 20.Substrate 26 can be a semiconductor substrate, such as,silicon, gallium arsenide, germanium, or other substrate55Mask or reticle 18 is a binary mask in one embodiment.Mask or reticle 18 includes a translucent substrate 32 (e.g.,glass or quartz) and an opaque or patterned layer 34 (e.g.,chromium or chromium oxide) thereon.
Opaque layer 34material. Substrate 26 can include one or more layers ofmaterial and/or features, such as lines, interconnects, vias,doped regions, etc., and can further include devices, such as,provides a pattern or image associated With a desired circuittransistors, microactuators, microsensors, capacitors,pattern, features, or devices to be projected onto photoresistlayer 30. Alternatively, mask or reticle 18 may be anresistors, diodes, etc.attenuating phase shift mask, an alternating phase shiftLayer 28 can be an insulative layer, a conductive layer, abarrier layer, or other layer of material to be etched, doped,mask, or other type of mask or reticle.or layered.
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