A compound with enhanced etching resistance, gap-filling properties, and heat resistance includes a repeating unit represented by Formula 1.

##STR00001##

Embodiments of the present disclosure generally relate to a multilayer stack used as a mask in extreme ultraviolet (EUV) lithography and methods for forming a multilayer stack. In one embodiment, the method includes forming a carbon layer over a film stack, forming a metal rich oxide layer on the carbon layer by a physical vapor deposition (PVD) process, forming a metal oxide photoresist layer on the metal rich oxide layer, and patterning the metal oxide photoresist layer. The metal oxide photoresist layer is different from the metal rich oxide layer and is formed by a process different from the PVD process. The metal rich oxide layer formed by the PVD process improves adhesion of the metal oxide photoresist layer and increases the secondary electrons during EUV lithography, which leads to decreased EUV dose energies.

An object of the present invention is to provide: a compound containing an imide group which is not only cured under film formation conditions of inert gas as well as air, generates no by-product and has excellent heat resistance and properties of filling and planarizing a pattern formed on a substrate, but can also form an organic underlayer film with favorable adhesion to a substrate. The present invention provides a material for forming an organic film, including: (A) a compound for forming an organic film shown by the following general formula (1A) or (1B); and (B) an organic solvent, ##STR00001##
noting that in the general formula (1A), when W.sub.1 represents any of ##STR00002##
R.sub.1 does not represent any of ##STR00003##

A method of manufacturing a semiconductor device includes forming a first resist layer over a substrate, and forming a second resist layer over the first resist layer. The second resist layer is patterned to expose a portion of the first resist layer to form a second resist layer pattern. The first resist layer is exposed to extreme ultraviolet (XUV) radiation diffracted by the second resist layer pattern. Portions of the first resist layer exposed to the XUV radiation diffracted by the second resist layer are removed.

A method includes applying a composition for forming a resist underlayer film to a substrate having a recess in a surface, and baking the composition for forming a resist underlayer film to form a resist underlayer film for filling at least the recess. The composition for forming a resist underlayer film has a copolymer having a structural unit of following formula (1), a cross-linkable compound, a cross-linking catalyst, and a solvent: ##STR00001## wherein R.sup.1 and R.sup.2 are each independently a C.sub.1-3 alkylene group or a single bond, Z is an —O— group, a —S— group, or a —S—S— group, and Ar is an arylene group.

An exemplary semiconductor fabrication stack includes underlying layers; an organic planarization layer atop the underlying layers; a metal oxide hardmask atop the organic planarization layer and doped with both carbon and nitrogen; and an organic photoresist directly atop the doped metal oxide hardmask. In one or more embodiments, the doped metal oxide hardmask exhibits a water contact angle of greater than 80°.

A protective film forming composition which has a good mask (protection) function against a wet etching liquid and a high dry etching rate during processing of a semiconductor substrate and also has good coverage even for a stepped substrate, and from which a flat film can be formed due to a small difference in film thickness after being embedded; a protective film produced using the composition; a substrate with a resist pattern; and a method for producing a semiconductor device. This composition contains: (A) a compound having three or more carboxyl groups; (B) a resin or a monomer; and a solvent. The compound (A) having three or more carboxyl groups preferably has a ring structure. This ring structure is preferably selected from among an aromatic ring having 6-40 carbon atoms, an aliphatic ring having 3-10 carbon atoms, and a heterocyclic ring.

A lithographic method for making an out-of-plane optical coupler includes forming a photoresist layer of positive photoresist material over a substrate. The positive photoresist layer undergoes a flood exposure to light through a binary mask to pattern a latent image of a mirror blank in the photoresist layer. A laser beam is scanned over the latent image of the mirror blank to apply controlled dosages of light at specified locations to form a latent image of a planar mirror surface that is oriented at a prescribed non-zero angle to a plane in which the substrate extends. The positive photoresist material is developed so that a remaining portion of the developed positive photoresist material forms an out-of-plane optical coupler having a planar mirror surface that is oriented at the prescribed angle.

A photoresist underlayer composition, comprising: a first polymer comprising a crosslinkable group; a second polymer comprising: a first repeating unit comprising a repeating unit comprising a photoacid generator, and a second repeating unit comprising a hydroxy-substituted C.sub.1-30 alkyl group, a hydroxy-substituted C.sub.3-30 cycloalkyl group, or a hydroxy-substituted C.sub.6-30 aryl group; an acid catalyst; and a solvent.

A method includes providing a layered structure on a substrate, the layered structure including a bottom layer formed over the substrate and a photoresist layer formed over the bottom layer, exposing the photoresist layer to a radiation source, developing the photoresist layer, patterning the bottom layer and removing portions of the substrate through openings in the patterned bottom layer. In some embodiments, a middle layer is provided between the bottom layer and the photoresist layer. The material of the bottom layer includes at least one cross-linking agent that has been functionalized to decrease its affinity to other materials in the bottom layer.