Abstract: Provided is an aromatic hydrocarbon resin with a high carbon concentration and a low oxygen concentration that can be used as a coating agent or a resist resin for semiconductors, as well as a composition for forming an underlayer film for photolithography with excellent etching resistance as an underlayer film for a multilayer resist process, an underlayer film formed from the composition, and a method for forming a pattern using the underlayer film. An aromatic hydrocarbon, an aromatic aldehyde, and a phenol derivative are reacted in the presence of an acidic catalyst to yield an aromatic hydrocarbon resin with a high carbon concentration of 90 to 99.9 mass % and a solubility in propylene glycol monomethyl ether acetate of 10 mass % or more.

Abstract: Spacers are formed by pitch multiplication and a layer of negative photoresist is deposited on and over the spacers to form additional mask features. The deposited negative photoresist layer is patterned, thereby removing photoresist from between the spacers in some areas. During patterning, it is not necessary to direct light to the areas where negative photoresist removal is desired, and the clean removal of the negative photoresist from between the spacers is facilitated. The pattern defined by the spacers and the patterned negative photoresist is transferred to one or more underlying masking layers before being transferred to a substrate.

Abstract: A pattern-forming method includes: (1) a resist underlayer film-forming step of providing a resist underlayer film on an upper face side of a substrate by coating a resist underlayer film-forming composition containing a resin having a phenolic hydroxyl group; (2) a resist pattern-forming step of forming a resist pattern on an upper face side of the resist underlayer film; (3) a pattern-forming step of dry etching at least the resist underlayer film and the substrate, with the aid of the resist pattern as a mask to form a pattern on the substrate; and (4) a resist underlayer film-removing step of removing the resist underlayer film on the substrate with a basic solution, in the order of (1) to (4).

Abstract: The invention relates to an antireflective coating composition for a photoresist layer comprising a polymer, a crosslinking agent and an acid generator, where the polymer comprises at least one unit of structure 1, where, X is a linking moiety selected from a nonaromatic (A) moiety, aromatic (P) moiety and mixture thereof, R? is a group of structure (2), R? is independently selected from hydrogen, a moiety of structure (2), Z and W—OH, where Z is a (C1-C20) hydrocarbyl moiety and W is a (C1-C20) hydrocarbylene linking moiety, and, Y? is independently a (C1-C20) hydrocarbylene linking moiety, where structure (2) is where R1 and R2 are independently selected from H and C1-C4alkyl and L is an organic hydrocarbyl group. The invention further relates to a process for imaging the antireflective coating composition.

Abstract: Techniques are provided for making a funnel-shaped nozzle in a semiconductor substrate. The funnel-shaped recess includes a straight-walled bottom portion and a curved top portion having a curved sidewall gradually converging toward and smoothly joined to the straight-walled bottom portion, and the curved top portion encloses a volume that is substantially greater than a volume enclosed by the straight-walled bottom portion.

Abstract: A pattern-formed substrate is provided. The pattern-formed substrate includes a substrate base, an organic thin film and an inorganic resist film stacked on the substrate base in this order, and patterns having predetermined aspect ratios formed on the organic thin film and the inorganic resist film, respectively. The pattern of the organic thin film is formed by selective etching using the pattern of the inorganic resist film as a mask.

Abstract: Disclosed is a method of patterning a layered material. A layered material is provided, and a photoresist layer is formed thereon. The photoresist layer is patterned by a focused laser beam to expose a part of the layered material. The exposed layered material is etched to pattern the layered material.

Abstract: The present invention relates to a photomask and a method for forming an overlay mark in a substrate using the same. The photomask comprises a plurality of patterns. At least one of the patterns comprises a plurality of ring areas and a plurality of inner areas enclosed by the ring areas, wherein the light transmittancy of the ring areas is different from that of the inner areas. When the photomask is applied in a photolithography process, the formed overlay mark has a large thickness. Therefore, the contrast is high when a metrology process is performed, and it is easy to find the overlay mark.

Abstract: Collapse of resist patterns in the formation of resist patterns that employ chemically amplified resist material is suppressed. A method for forming a resist pattern includes the steps of: coating a substrate with a chemically amplified resist material; exposing the resist material; and developing the exposed resist material, to form a resist pattern having an aspect ratio AR of 1.5 or greater in a resist film formed by the resist material. A close contact process that improves close contact properties between the substrate and the resist film is controlled such that the thickness of residual film of the resist film is greater than or equal to 1 nm and less than or equal to 1.83·AR+1.73 nm.

Abstract: The invention is directed to a method for patterning a material layer. The method comprises steps of forming a first mask layer on the material layer and then patterning the first mask layer. The patterned first mask layer has a pattern therein and a plurality of gaps within the patterns and the gaps expose a portion of the material layer. Further, a second mask layer is formed over the material layer and the second mask layer fills the gaps. An interface layer is formed between the patterned first mask layer and the second mask layer. A portion of the second material layer is removed until the top surface of the interface layer is exposed. The interface layer is removed to expose a portion of the material layer and the material layer is patterned by using the patterned first mask layer and the second mask layer as a mask.

Abstract: A combined laminating and exposing apparatus for exposing a photosensitive printing blank to actinic radiation in a printing plate manufacturing system and a method of using the same are disclosed. The photosensitive printing blank comprises a backing layer, at least one photocurable layer disposed on the backing layer, and a laser ablatable mask layer disposed on the at least one photocurable layer, wherein the laser ablatable mask layer is laser ablated to create an in situ negative in the laser ablatable mask layer. The exposing apparatus comprises: (a) a laminating apparatus for laminating an oxygen barrier layer to a top of the laser ablated mask layer; (b) a conveyor; (c) a first exposing device for imagewise exposing the at least one photocurable layer to actinic radiation, and (d) a second exposing device for exposing the at least one photocurable layer to actinic radiation through the backing layer.

Abstract: A polymer comprising a siloxane polymer having at least one Si—OH group and at least one Si—OR group, where R is condensation stabilizing group optionally having a reactive functional group, wherein the siloxane polymer, when placed into a solvent, has a weight average molecular weight increase of less than or equal to 50% after aging for one week at 40° C. as measured by GPC is provided.

Abstract: A pattern-forming method includes coating a radiation-sensitive resin composition on a substrate to provide a resist film. The resist film is exposed. The exposed resist film is developed. A developer solution used in developing the exposed resist film includes no less than 80% by mass of an organic solvent. The radiation-sensitive resin composition includes a first polymer and a radiation-sensitive acid generator. The first polymer includes a first structural unit having an acid-labile group and an alicyclic group. The alicyclic group is capable of avoiding dissociation from a molecular chain by an action of an acid.

Abstract: A first metallic hard mask layer over an interconnect-level dielectric layer is patterned with a line pattern. At least one dielectric material layer, a second metallic hard mask layer, a first organic planarization layer (OPL), and a first photoresist are applied above the first metallic hard mask layer. A first via pattern is transferred from the first photoresist layer into the second metallic hard mask layer. A second OPL and a second photoresist are applied and patterned with a second via pattern, which is transferred into the second metallic hard mask layer. A first composite pattern of the first and second via patterns is transferred into the at least one dielectric material layer. A second composite pattern that limits the first composite pattern with the areas of the openings in the first metallic hard mask layer is transferred into the interconnect-level dielectric layer.

Abstract: Methods of forming a pattern in a material and methods of forming openings in a material to be patterned are disclosed, such as a method that includes exposing first portions of a first material to radiation through at least two apertures of a mask arranged over the first material, shifting the mask so that the at least two apertures overlap a portion of the first portions of the first material, and exposing second portions of the first material to radiation through the at least two apertures. The first portions and the second portions will overlap in such a way that non-exposed portions of the first material are arranged between the first portions and second portions. The non-exposed or exposed portions of the first material may then be removed. The remaining first material may be used as a photoresist mask to form vias in an integrated circuit. The pattern of vias produced have the capability to exceed the current imaging resolution of a single exposure treatment.

Abstract: Methods of forming a patterned, silicon-enriched developable antireflective material. One such method comprises forming a silicon-enriched developable antireflective composition. The silicon-enriched developable antireflective composition comprises a silicon-enriched polymer and a crosslinking agent. The silicon-enriched polymer and the crosslinking agent are reacted to form a silicon-enriched developable antireflective material that is insoluble and has at least one acid-sensitive moiety. A positive-tone photosensitive material, such as a positive-tone photoresist, is formed over the silicon-enriched developable antireflective material and regions thereof are exposed to radiation. The exposed regions of the positive-tone photosensitive material and underlying regions of the silicon-enriched developable antireflective material are removed. Additional methods are disclosed, as are semiconductor device structures including a silicon-enriched developable antireflective material.

Abstract: Embodiments of the present invention relate to lithographic processes used in integrated circuit fabrication for improving line edge roughness (LER) and reduced critical dimensions (CD) for lines and/or trenches. Embodiments use the combinations of polarized light lithography, shrink coating processes, and double exposure processes to produce synergetic effects in the formation of trench structures having good resolution, reduced CDs, reduced pitch, and reduced LER in the lines and/or trenches of the patterned interconnect structures.

Abstract: The present invention provides a method of forming one or more biological-binding areas on a substrate for biological-testing. The method includes activating at least a portion of a glass-ceramic substrate comprising glass and one or more metal containing compounds. The one or more metal containing compounds have a range of diameters that are less than about 300 nanometers in diameter and are spaced an average distance of at least one-half the midpoint of the diameter range apart. The one or more metals include compounds selected from metal oxides, metal nanoparticles, metal alloys, and atomic metals. The glass-ceramic substrate is heated to a temperature near the glass transformation temperature to form one or more metal nanoparticles in one or more ceramic biological-binding areas. The glass-ceramic substrate is etched to expose one or more metal.

Abstract: A method for fabricating patterned graphene structures, which adopts a photolithographic etching process to fabricate patterned graphene structures, comprises steps: providing a substrate; forming a catalytic layer on the substrate; forming a carbon layer on the catalytic layer; heating the carbon layer to a synthesis temperature to form a graphene layer. A photolithographic etching process is performed on the catalytic layer before formation of the carbon layer. Alternatively, a photolithographic etching process is performed on the carbon layer before heating. Alternatively, a photolithographic etching process is performed on the graphene layer after heating. Compared with the laser etching process, the photolithographic etching process is suitable to fabricate large-area patterned graphene structures and has advantages of high productivity and low cost.

Abstract: The present invention relates to the implementation of minute patterns and thus improving pattern resolution and transcription property. Provided is a printing substrate for a liquid crystal display comprising a transparent insulating substrate, and a material layer for dry etching formed on an upper surface of the transparent insulating substrate, the material layer for dry etching constituting a printing pattern, and a manufacturing method of a printing substrate for a liquid crystal display comprising forming a material layer on a transparent insulating substrate, applying a photo resist along a printing pattern on the upper side of the material layer, dry-etching the material layer along the printing pattern using the photo resist as an etching mask, and striping the photo resist.

Abstract: A pattern clean-up for fabrication of patterned media using a forced assembly of molecules is disclosed. E-beam lithography is initially used to write the initial patterned bit media structures, which have size and positioning errors. Nano-sized protein molecules are then forced to assemble of on top of the bits. The protein molecules have a very uniform size distribution and assemble into a lattice structure above the e-beam patterned areas. The protein molecules reduce the size and position errors in e-beam patterned structures. This process cleans the signal from the e-beam lithography and lowers the noise in the magnetic reading and writing. This process may be used to fabricate patterned bit media directly on hard disk, or to create a nano-imprint master for mass production of patterned bit media disks.

Abstract: Some embodiments include methods in which spaced-apart first features are formed from a first material having a reflow temperature. Second material is formed along sidewalls of the first features, and third material is formed over the second material and the first features. The third material may be formed at a temperature above the reflow temperature of the first material, and the second material may support the first features so that the first features do not collapse even though they are exposed to such temperature. In some embodiments the third material has an undulating topography. Fourth material may be formed within the valleys of the undulating topography, and subsequently the first features may be removed together with at least some of the third material to leave a pattern comprising second features formed from the second material and pedestals formed from the fourth material.

Abstract: The present invention relates to a photomask and a method for forming an overlay mark in a substrate using the same. The photomask comprises a plurality of patterns. At least one of the patterns comprises a plurality of ring areas and a plurality of inner areas enclosed by the ring areas, wherein the light transmittancy of the ring areas is different from that of the inner areas. When the photomask is applied in a photolithography process, the formed overlay mark has a large thickness. Therefore, the contrast is high when a metrology process is performed, and it is easy to find the overlay mark.

Abstract: A micro-mirror well. In one embodiment the micro-mirror well includes a plurality of planar mirrors arranged around an axis of symmetry and inclined to form a pyramid well, where each of the plurality of planar mirrors is capable of reflecting light emitting from an object of interest placed inside the pyramid well.

Abstract: A plurality of reticles for printing structures in the same lithography level includes an alignment structure pattern within a same relative location in each reticle. Each set of process segmentations in a grating has a reticle segmentation pitch, which is common across all gratings in the plurality of reticles. Within each pair of alignment structure patterns that occupy the same relative location in any two of the plurality of reticles, the process segmentations in one reticle are shifted relative to the process segmentations in the other reticle by a fraction of a reticle segmentation pitch. After printing all patterns in the plurality of reticles, a composite printed process segmentation structure on the substrate includes printed segmentation structures that are spaced by 1/n times the printed segmentation pitch. The pattern for the next level can be aligned to the composite printed process segmentation structure in a single alignment operation.

Abstract: According to one embodiment, a mask used with an exposure apparatus is disclosed. The mask includes a main pattern, and a sub-pattern having a dimension smaller than a resolution limit of the exposure apparatus. The sub-pattern is arranged next to the main pattern. The sub-pattern includes a first sub-pattern arranged next to the main pattern, and second sub-patterns contacting the first sub-pattern and arranged along a longitudinal direction of the first sub-pattern. The sub-patterns satisfy a condition of P??/(NA(1+?0)). Where P is a pitch of the second sub-patterns, NA is a numerical aperture of the exposure apparatus, ? and ?0 are respectively exposure wave length and maximum ? when the main pattern by using the exposure apparatus.

Abstract: A method of lithography patterning includes forming a first resist pattern on a substrate, the first resist pattern including a plurality of openings therein on the substrate; forming a second resist pattern on the substrate and within the plurality of openings of the first resist pattern, the second resist pattern including at least one opening therein on the substrate; and removing the first resist pattern to uncover the substrate underlying the first resist pattern.

Abstract: The present invention provides novel methods of fabricating microelectronics structures, and the resulting structures formed thereby, using EUV lithographic processes. The method involves utilizing an assist layer immediately below the photoresist layer. The assist layer can either be directly applied to the substrate, or it can be applied to any intermediate layer(s) that may be applied to the substrate. The preferred assist layers are formed from spin-coatable, polymeric compositions. The inventive method allows reduced critical dimensions to be achieved with improved dose-to-size ratios, while improving adhesion and reducing or eliminating pattern collapse issues.

Abstract: A polysiloxane composition includes a polysiloxane, and a first compound. The first compound includes a nitrogen-containing heterocyclic ring structure, and a polar group, an ester group or a combination thereof. A pattern-forming method includes coating the polysiloxane composition on a substrate to be processed to provide a silicon-containing film. A resist composition is coated on the silicon-containing film to provide a resist coating film. The resist coating film is selectively irradiated with a radioactive ray through a photomask to expose the resist coating film. The exposed resist coating film is developed to form a resist pattern. The silicon-containing film and the substrate to be processed are sequentially dry etched using the resist pattern as a mask.

Abstract: A hardmask composition includes an organic solvent and one or more aromatic ring-containing polymers represented by Formulae 1, 2 and 3:

Abstract: The present invention relates to a positive photosensitive composition suitable for image-wise exposure and development as a positive photoresist comprising a positive photoresist composition and an inorganic particle material having an average particle size equal or greater than 10 nanometers, wherein the thickness of the photoresist coating film is less than 5 microns. The positive photoresist composition can be selected from (1) a composition comprising (i) a film-forming resin having acid labile groups, and (ii) a photoacid generator, or (2) a composition comprising (i) a film-forming novolak resin, and (ii) a photoactive compound, or (3) a composition comprising (i) a film-forming resin, (ii) a photoacid generator, and (iii) a dissolution inhibitor. The invention also relates to a process of forming an image using the novel photosensitive composition.

Abstract: A structure having an optical slit therein. The structure includes a substrate having an opening therethrough and a metal layer disposed on the substrate, such metal layer having a photolithographically formed slit therein, such slit being narrower than the opening and being disposed over the opening, portions of the metal layer disposed adjacent the slit being suspended over the opening and other portions of the metal layer being supported by the substrate.

Abstract: In accordance with the invention, there are methods for self-aligned spatial frequency doubling in one dimension and also in two dimension. The method for self-aligned spatial frequency doubling in one dimension can include forming a film stack over a substrate, wherein the film stack comprises a photoresist layer and forming a one-dimensional periodic first pattern having a first pitch p on the photoresist layer using an optical exposure, wherein the first pitch p is at least smaller than twice the bandpass limit for optical exposures. The method can also include forming a second pattern using the first pattern by nonlinear processing steps, wherein the second pattern has a second pitch p2=p/2.

Abstract: There is provided a resist underlayer film for lithography causing no intermixing with a photoresist and having a dry etching rate higher than that of the photoresist, and a resist underlayer film forming composition for forming the underlayer film. A resist underlayer film forming composition for lithography comprising: a polymer containing a partial structure of Formula (1): where X1 is a group of Formula (2), Formula (3), Formula (4) or Formula (4-1): and a solvent. The polymer may contain, besides the partial structure of Formula (1), a partial structure of Formula (5): (R1)a(R3)bSi(O—)4?(a+b)??Formula (5) and/or a partial structure of Formula (6): [(R4)cSi(O—)3?c]2Y??Formula (6).

Abstract: A method of fine patterning a thin film and a method of manufacturing a display substrate by using the same, in which a fine photo pattern is formed on a base substrate, and a photoresist pattern is formed on the thin film. A fine photo pattern is formed by ashing the photoresist pattern. A fine pattern is formed by removing the thin film exposing through the fine photo pattern. A fine pattern is formed, and the fine pattern has a higher resolution than that of an exposure apparatus. The reliability of a process for manufacturing a display substrate and the display quality of a display device may be improved.

Abstract: An optical arrangement has a laser configured to emit a laser beam, an amplitude mask and a focusing element. The amplitude mask is disposed between the laser and the focusing element in a path of the laser beam such that the laser beam hits the amplitude mask before being modified by the focusing element so as to direct the laser beam to a focal point within a photosensitive material.

Abstract: This is structure and method for providing a textured surfaced that can be used in a plurality of systems including ink jet printing. In ink jet printing, the textured surface of this invention controls ink drawback and significantly improves image quality. The textured surface has an average roughness, Ra, of about 0.2 to 1.5 microns, a texture density of about 104-107 pits per cm2, a texture size of about 0.5-5 microns, and a texture depth of about 0.5-10 microns.

Abstract: The present disclosure provides a method of making a mask. The method includes providing a substrate having a first attenuating layer on the substrate and a first imaging layer on the first attenuating layer; performing a first exposure to the first imaging layer using a first radiation energy in writing mode; performing a first etching to the first attenuating layer; performing a second etching to the substrate; forming a second imaging layer on the first attenuating layer and the substrate; performing a second exposure to the second imaging layer using a light energy and another mask; and performing a third etching to the first attenuating layer after the second exposure.

Abstract: A method of processing a substrate includes forming first photoresist on a substrate. A portion of the first photoresist is selectively exposed to actinic energy and then the first photoresist is negative tone developed to remove an unexposed portion of the first photoresist. Second photoresist is formed on the substrate over the developed first photoresist. A portion of the second photoresist is selectively exposed to actinic energy and then the second photoresist is negative tone developed to remove an unexposed portion of the second photoresist and form a pattern on the substrate which comprises the developed first photoresist and the developed second photoresist. Other implementations are disclosed.

Abstract: This invention provides a method for reducing tip-to-tip spacing between lines using a combination of photolithographic and copolymer self-assembling lithographic techniques. A mask layer is first formed over a substrate with a line structure. A trench opening of a width d is created in the mask layer. A layer of a self-assembling block copolymer is then applied over the mask layer. The block copolymer layer is annealed to form a single unit polymer block of a width or a diameter w which is smaller than d inside the trench opening. The single unit polymer block is selectively removed to form a single opening of a width or a diameter w inside the trench opening. An etch transfer process is performed using the single opening as a mask to form an opening in the line structure in the substrate.

Abstract: A lithographic structure comprising: an organic antireflective material disposed on a substrate, and a silicon antireflective material disposed on the organic antireflective material. The silicon antireflective material comprises a crosslinked polymer with a SiOx backbone, a chromophore, and a transparent organic group that is substantially transparent to 193 nm or 157 nm radiation. In combination, the organic antireflective material and the silicon antireflective material provide an antireflective material suitable for deep ultraviolet lithography. The invention is also directed to a process of making the lithographic structure.

Abstract: The present invention relates to a fluorine-free photoacid generator (PAG) and a photoresist composition containing the same. The PAG is characterized by the presence of an onium cationic component and a fluorine-free fused ring heteroaromatic sulfonate anionic component containing one or more electron withdrawing substituents. The onium cationic component of the PAG is preferably a sulfonium or an iodonium cation. The photoresist composition further contains an acid sensitive imaging polymer. The photoresist composition is especially useful for forming material patterns on a semiconductor substrate using 193 nm (ArF) lithography.

Abstract: The present invention relates to a fluorine-free photoacid generator (PAG) and a photoresist composition containing the same. The PAG is characterized by the presence of an onium cationic component and a fluorine-free fused ring heteroaromatic sulfonate anionic component containing one or more electron withdrawing substituents. The onium cationic component of the PAG is preferably a sulfonium or an iodonium cation. The photoresist composition further contains an acid sensitive imaging polymer. The photoresist composition is especially useful for forming material patterns on a semiconductor substrate using 193 nm (ArF) lithography.

Abstract: The present invention relates to a fluorine-free photoacid generator (PAG) and a photoresist composition containing the same. The PAG is characterized by the presence of an onium cationic component and a fluorine-free fused ring heteroaromatic sulfonate anionic component containing one or more electron withdrawing substituents. The onium cationic component of the PAG is preferably a sulfonium or an iodonium cation. The photoresist composition further contains an acid sensitive imaging polymer. The photoresist composition is especially useful for forming material patterns on a semiconductor substrate using 193 nm (ArF) lithography.

Abstract: Disclosed is a method for stripping a photoresist comprising: (I) providing a photoresist pattern on a substrate where the substrate has at least a copper (Cu) wiring and a low-dielectric layer thereon, and selectively etching the low-dielectric layer by using the photoresist pattern as a mask; (II) contacting the substrate after the step (I), with ozone water and/or aqueous hydrogen peroxide; and (III) contacting the substrate after the step (II), with a photoresist stripping solution that contains at least a quaternary ammonium hydroxide.

Abstract: Disclosed is a resist ink having superior acid-resistance and coupling property, the resist ink composed of 70% or less by weight of solvent, 10-15% by weight of base polymer, 10-15% by weight of tacktifier, 3% or less by weight of additive, and 1-10% by weight of coupling agent.

Abstract: The present invention relates to a fluorine-free photoacid generator (PAG) and a photoresist composition containing the same. The PAG is characterized by the presence of an onium cationic component and a fluorine-free fused ring heteroaromatic sulfonate anionic component containing one or more electron withdrawing substituents. The onium cationic component of the PAG is preferably a sulfonium or an iodonium cation. The photoresist composition further contains an acid sensitive imaging polymer. The photoresist composition is especially useful for forming material patterns on a semiconductor substrate using 193 nm (ArF) lithography.

Abstract: The present invention relates to a fluorine-free photoacid generator (PAG) and a photoresist composition containing the same. The PAG is characterized by the presence of an onium cationic component and a fluorine-free fused ring heteroaromatic sulfonate anionic component containing one or more electron withdrawing substituents. The onium cationic component of the PAG is preferably a sulfonium or an iodonium cation. The photoresist composition further contains an acid sensitive imaging polymer. The photoresist composition is especially useful for forming material patterns on a semiconductor substrate using 193 nm (ArF) lithography.

Abstract: The present invention relates to a fluorine-free photoacid generator (PAG) and a photoresist composition containing the same. The PAG is characterized by the presence of an onium cationic component and a fluorine-free fused ring heteroaromatic sulfonate anionic component containing one or more electron withdrawing substituents. The onium cationic component of the PAG is preferably a sulfonium or an iodonium cation. The photoresist composition further contains an acid sensitive imaging polymer. The photoresist composition is especially useful for forming material patterns on a semiconductor substrate using 193 nm (ArF) lithography.

Abstract: Metal-oxide films for lithographic applications are provided. The films are formed from compositions comprising metal-oxide precursor compounds including metals and metalloids other than silicon. These films are easily produced and can be modified with a variety of ligands, including alkoxides, phenoxides, carboxylates, beta-diketones, and beta-ketoesters.