The present invention provides a tetracarboxylic acid diester compound shown by the following general formula (1),

##STR00001##

wherein X.sub.1 represents a tetravalent organic group; and R.sub.1 represents a group shown by the following general formula (2),

##STR00002##

wherein the dotted line represents a bond; Y.sub.1 represents an organic group with a valency of k+1; “k” represents 1 or 2; and “n” represents 0 or 1. There can be provided a tetracarboxylic acid diester compound that can give a polyimide precursor polymer soluble in a safe organic solvent widely used as a solvent of a composition and usable as a base resin of a photosensitive resin composition.

A resist composition including a compound represented by formula (b1) in which R.sup.b1 represents an aryl group which may have a substituent; R.sup.b2 and R.sup.b3 each independently represents an aryl group which may have a substituent or an alkyl group which may have a substituent; provided that at least one of the aryl group represented by R.sup.b1 and the aryl group or the alkyl group represented by R.sup.b2 or R.sup.b3 has a substituent containing a halogen atom, and at least one of the aryl group represented by R.sup.b1 and the aryl group or the alkyl group represented by R.sup.b2 or R.sup.b3 has a substituent containing a sulfonyl group; and X.sup.− represents a counteranion ##STR00001##

Provided are a metasurface primary mirror, a metasurface secondary mirror, a method for manufacturing a metasurface primary mirror, a method for manufacturing a metasurface secondary mirror, and an optical system. The metasurface primary mirror, manufactured by using the method for manufacturing a metasurface primary mirror, includes a transparent substrate which includes a primary mirror metasurface pattern on the transparent substrate. The primary mirror metasurface is configured to satisfy a primary mirror phase distribution such that incident light reflected by a metasurface secondary mirror onto the metasurface primary mirror is reflected and focused.

Cantilevers, SPM tips and nanomachining tools are created in the plane of wafers to obtain new and high performance parts. The method produces more parts for any given wafer, then conventional methods and allows every part on any given wafer to be different from any other, permitting great freedom in new SPM and nanomachining techniques and product development.

Provided are an active-light-sensitive or radiation-sensitive resin composition in which the sensitivity is excellent, and an active-light-sensitive or radiation-sensitive film, a pattern forming method, and a method for manufacturing an electronic device, each using the active-light-sensitive or radiation-sensitive resin composition. The active-light-sensitive or radiation-sensitive resin composition contains a resin (Ab) whose polarity is changed by the action of an acid, and a compound that generates an acid upon irradiation with active light or radiation, in which the resin (Ab) includes a metal ion, and the metal type of the metal ion is at least one of metal types belonging to Groups 1 to 10 and 13 to 16 (here, excluding Mg and Cs).

A radiation-sensitive composition includes particles including a metal oxide as a principal component, a radiation-sensitive acid generator, and an organic solvent. A metal atom constituting the metal oxide includes a first metal atom that is a zinc atom, a boron atom, an aluminum atom, a gallium atom, a thallium atom, a germanium atom, an antimony atom, a bismuth atom, a tellurium atom, or a combination thereof. A van der Waals volume of an acid generated from the radiation-sensitive acid generator is no less than 2.0×10.sup.−28 m.sup.3. A percentage content of the first metal atom with respect to total metal atoms in the radiation-sensitive composition is no less than 50 atomic %.

A non-chemically-amplified positive resist composition comprising a polymer comprising both recurring units derived from a sulfonium salt capable of generating a fluorinated acid and recurring units containing an amino group as a base resin exhibits a high resolution and a low edge roughness and forms a pattern of good profile after exposure and organic solvent development.

A radiation-sensitive composition includes particles including a metal oxide as a principal component, and an organic solvent. A metal atom constituting the metal oxide includes a first metal atom that is a zinc atom, a boron atom, an aluminum atom, a gallium atom, a thallium atom, a germanium atom, an antimony atom, a bismuth atom, a tellurium atom, or a combination thereof. A percentage content of the first metal atom with respect to total metal atoms in the radiation-sensitive composition is no less than 50 atomic %. A pattern-forming method includes applying the radiation-sensitive composition to form a film on a substrate, exposing the film, and developing the film exposed.

A negative resist composition comprising an onium salt having formula (A) and a base polymer is provided. The resist composition exhibits a high resolution during pattern formation and forms a pattern with minimal LER. ##STR00001##

The composition for forming an underlayer film for lithography according to the present invention contains a compound represented by a specific formula (1) and 20 to 99% by mass of a solvent component (S), in which 27 to 100% by mass of the compound represented by the formula (1) is included in a component (A) other than the solvent component (S).