Abstract: The invention relates to a radiation-sensitive ester which is the condensation product of (a) a compound containing 2 to 6 aromatic hydroxyl groups, (b) a ring-substituted (o-naphthoquinone 2-diazide)-4-sulfonic acid (compound D.sub.1 and (c) an (o-naphthoquinone 2-diazide)-4- or -5-sulfonic acid which is not further substituted (compound D.sub.2) and/or a non-radiation-sensitive organic acid (compound D.sub.0), where the (b):(c) molar ratio is between 0.1:1 and 39:1.

Abstract: A filter is formed on a solid state imager by:forming, on the imaging surface of the imager, an adherent layer of a dye-containing photoresist composition comprising a photoresist resin and a thermochromic dye, this dye being substantially non-absorbent of actinic radiation of a first wavelength, but capable, upon heating, of undergoing a thermally-induced color change which renders it absorptive of actinic radiation of the first wavelength;imagewise exposing the adherent layer of dye-containing photoresist composition to actinic radiation of the first wavelength;removing one of the exposed and unexposed areas of the layer, while leaving the other of the exposed and unexposed areas on the imaging surface, to form a pattern of filter elements; andheating the solid state imager to a temperature and for a time sufficient to cause the dye to undergo its color change, thereby causing the filter elements to become absorptive of radiation of the first wavelength.

Abstract: A photoresist comprising a light sensitive component and an essentially aromatic alkali soluble novolak resin comprising the product resulting from the acid condensation of an aromatic aldehyde and a phenol where the resin has a molecular weight in excess of 1,500 and a glass transition temperature in excess of 125.degree. C. If desired, the aromatic novolak resin may be blended with a conventional novolak resin to regulate the glass transition temperature of the resin.

Abstract: Disclosed herein is a photosensitive resin composition composed mainly of an alkali-soluble organometallic polymer and a photosensitive dissolution inhibitor. The composition is used as a positive type resist which can be developed with an alkali developing solution. The resist has high sensitivity, high resolution, and resistance to oxygen plasma.

Abstract: A photosensitizer composition comprising a diazo fluorinated ester containing the hexafluoroisopropylidene group, said photosensitizer selected from hexafluoro-bis-phenols having the following formula: ##STR1## where R is selected from hydrogen, methyl, ethyl and phenyl; and bis-hexafluoroethers having the following formula: ##STR2## wherein R' is selected from hydrogen, methyl, ethyl and phenyl.

Abstract: A positive-working radiation-sensitive mixture is described which essentially contains a photoactive component and a water-insoluble binder which is soluble, or at least swellable, in aqueous alkaline solution, wherein a compound is used, as photoactive component, which contains .alpha.-diazo-.beta.-keto ester units and sulfonate units of the formula I ##STR1## in which R.sup.1 and R.sup.2, independently of one another, are an unsubstituted or substituted aliphatic, cycloaliphatic, araliphatic or aromatic radical having 4 to 20 carbon atoms, it being possible for individual CH.sub.2 groups to be replaced by oxygen or sulfur atoms or by N or NH groups and/or contain keto groups,X is an unsubstituted or substituted aliphatic, cycloaliphatic, carbocyclic, heterocyclic or araliphatic radical having 2 to 22 carbon atoms, it being possible for individual CH.sub.2 groups to be replaced by oxygen or sulfur atoms or by the groups --NR.sup.3 --, --C(O)--0--, --C(O)--NR.sup.3 --, ##STR2## --NR.sup.3 --C(O)--NR.sup.

Abstract: A process for converting a normally positive working photosensitive composition to a negative working composition is disclosed. One forms a composition containing an alkali soluble resin, a 1,2 quinone diazide-4-sulfonyl compound and an acid catalyzed crosslinker in a solvent mixture. After drying and imagewise exposing, the composition is baked and developed to produce a negative image. The image-reversal negative-working photoresists of this invention have superior storage stability and shelf life.

Abstract: The present invention relates to a photosensitive composition comprising an o-quinonediazide compound and a polyurethane resin having a phosphonic acid group, a phosphoric acid group or its ester group. The photosensitive composition of the present invention provides an excellent adhesion to the support, an excellent developability with an aqueous alkali developer, and a high printing durability.

Abstract: A methylol-substituted trihydroxybenzophenone of the formula (I): ##STR1## This methylol-substituted trihydroxybenzophenone may be reacted with selected phenolic monomers during or after the formation of a phenolic novolak resin thereby said resin having at least one unit of formula (II): ##STR2## wherein R and R.sub.1 are individually selected from hydrogen, a lower alkyl group having 1 to 4 carbon atoms or a lower alkoxy group having 1 to 4 carbon atoms.

Abstract: A phenolic novolak resin composition comprising a condensation product of at least one aldehyde source with a phenolic source comprising 5-indanol. Said phenolic novolak resins are used in radiation-sensitive compositions, especially those useful as positive-working photoresists.

Abstract: A positive type photoresist composition which comprises an alkali soluble novolak resin and at least one light-sensitive material represented by the following general formulae (I) to (IV) to provide a resist pattern with high resolution, high reproduction fidelity, desirable sectional shape, wide latitude of development, high heat resistance and high storage stability: ##STR1## (wherein X represents --CO--, or --SO.sub.2 --; p represents an integer from 2 to 4; R's may be the same or different, each being --H, --OH, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted acyloxy group, ##STR2## provided that R always contains at least one of ##STR3## ; R.sub.

Abstract: This invention relates to novel radiation sensitive compositions. More particularly the invention relates to photoresists containing phosphorus and nitrogen linked polymers; i.e., polyphosphazenes, useful in the preparation of a relief pattern on a substrate; e.g., a silicon wafer or aluminum plate. The polyphosphazenes of in this invention can be synthesized by the condensation of N-trimethylsilylalkoxyphosphorimides. Radiation sensitive positive photoresist compositions of the invention can be developed in aqueous base developer or organic solvent developer The base developer dissolution properties of the composition can be controlled by incorporating carboxylate groups into the polyphosphazene. The polyphosphazenes utilized in this invention have good solubility properties in various organic solvents and also have good mechanical, electrical, adhesion and thermal properties.

Abstract: A developer composition for positive color proofing films containinga) sodium, potassium or ammonium octyl sulfate; sodium, potassium or ammonium lauryl sulfate; sodium decyl sulfate; or sodium tetradecyl sulfate; andb) sodium or potassium borate; andc) boric acid; andd) monobasic sodium or potassium phosphate; ande) sodium or potassium citrate; andf) sodium or potassium salicylate; andg) sodium, potassium or lithium benzoate; andh) sufficient water to formulate an effective developer.

Abstract: An electrophoretic positive working photosensitive composition for producing a photoresist pattern on metal base plate comprises a photosensitive compound, in which a photosensitive quinone diazide group is grafted on a polyester, and an acrylic copolymer containing carboxyl group, the composition forms a smooth photoresist film on the plate and has a good adhesion to the surface that no pinehole is found.

Abstract: This invention is that of high temperature polyamides containing the hexafluoroisopropylidene group. The high temperature polyamides of the invention and photo or radiation sensitizers provide improved high temperature positive resists which can be developed in aqueous alkaline developer and thermally anneal to form heat resistant, polyoxazole relief structures suitable for use in microelectronic and printing applications. The positive photoresists of the invention have improved solubility in coating solvents and improved photospeed. The polyamides of the invention can be prepared by conventional condensation reactions; e.g. the condensation of a diamine and diacid chloride. In addition the polyamides of this invention provide high temperature protective coatings with superior adhesion properties in applications other than the photoresist area.

Abstract: A composition containing an organosilicon material having terminal quinone groups, and a phenolic-novolak polymer, and use thereof in photolithography.

Abstract: There are disclosed a photosensitive composition which comprises:(1) an o-naphtoquinonediazide compound;(2) an alkali soluble resin; and(3) any one selected from the groups consisting of:(a) an ester compound of a polyoxyalkylene sorbitol fatty acid and/or an ether compound of the fatty acid,(b) an alkylene oxide adduct of castor oil, hardened castor oil, lanolin alcohol, beeswax, phytosterol or phytostanol, and(c) at least one activator selected from the group consisting of polyoxypropylene alkyl ethers, polyoxypropylene alkylphenyl ethers and polyoxypropylene alkyl esters;.and a photosensitive lithographic printing plate which comprises a support; and a photosensitive layer formed by applying the above photosensitive composition.

Abstract: A radiation-sensitive resin composition containing an alkali-soluble resin, comprising a polyhydroxy compound having the following formula: ##STR1## or a quinonediazidesulfonate of the polyhydroxy compound. The radiation-sensitive resin composition is suitable for use as a positive type photoresist which has such excellent developability as to inhibit effectively the generation of scum in the formation of a photoresist pattern, has high sensitivity and is excellent in heat resistance and remained thickness ratio upon development.

Abstract: The present invention provides a photosensitive resin composition which comprises, as essential components:(A) a polyamic acid having a recurring unit represented by the following formula [I]: ##STR1## wherein R.sub.1 and R.sub.2 each represents an organic group selected from the group consisting of an aromatic group, an alicyclic group, an aliphatic group, and a heterocyclic group and m is 1 or 2,(B) an amide compound having carbon-carbon double bond, and(C) a photosensitizer.

Abstract: A radiation-sensitive resin composition comprising a solution of an alkali-soluble resin and a radiation-sensitive compound in a solvent comprising a monooxymonocarboxylic acid ester. This composition has a high storage stability (i.e., a very small amount of fine particles are formed during storage) and is suited for use as a resist for making integrated circuits.

Abstract: A radiation-sensitive composition comprising an admixture in a solvent of: at least one alkali-soluble binder resin, at least one photoactive compound and an effective sensitivity enhancing amount of at least one polylactide compound; the amount of said binder resin being about 60 to 95% by weight, the amount of said photoactive component being about 5% to about 40% by weight, based on the total solids content of said radiation-sensitive composition.

Abstract: A photolithographic method for structure generation in bilayer processes is provided. Pursuant to the method, a dimensional reserve is produced in a top resist structure by chemical treatment with a bulging agent. The expansion preferably is performed by treatment with an aqueous solution. The expansion can be set such that the dimensional loss to be anticipated in further etchings of the bottom resist or, respectively, of the wafer is exactly compensated for.

Abstract: A block copolymer novolak resin composition comprising at least one unit of the reaction product of an alkali-soluble phenolic polymer and a reactive ortho, ortho bonded oligomer having the formula: ##STR1## wherein x is from 2 to 7; wherein R is selected from hydrogen a lower alkyl group or lower alkoxy group having 1-4 carbon atoms and a halogen group; and Y.sub.1 is either a hydroxyl group; an alkoxy group or a halogen group; and Y.sub.2 is hydrogen, alkyl, alkoxy, halogen, hydroxyl, --CH.sub.2 OH, --CH.sub.2 -- halogen, or --CH.sub.2 --alkoxy group.

Abstract: A coating of resin and photoactive functionality is autodeposited from an emulsion onto a metallic substrate in order to selectively protect the substrate from corrosive environments such as etchant processes. An acid and oxidizing agent are included in the emulsion so that when the substrate is immersed in the emulsion the resin and photoactive functionality autodeposits. The resulting coating can be exposed to actinic radiation in an image-wise fashion and developed in an alkaline solution to develop the image created. In instances where the emulsion and process are used to make circuit boards, the metallic surface uncovered during developing is then etched away, leaving only the coated sections of the surface. The resulting coated surfaces will be the circuit traces of the circuit board.

Abstract: A positive type photosensitive resinous composition comprising a binder resin and a quinone diazide compound, the binder resin being a copolymer of(a) at least one phosphoric acid ester monomer represented by the formula: ##STR1## (b) at least one acid group containing .alpha.,.beta.-ethylenically unsaturated monomer, and(c) other copolymerizable .alpha.,.beta.-ethylenically unsaturated monomers than (a) and (b), which is specifically useful for the formation of resist coating in the preparation of printed circuit board.

Abstract: Block phenolic oligomers of the formula (I): ##STR1## These may be reacted alone or with selected phenolic monomers during or after the formation of a phenolic novolak resin thereby said resin having at least one unit of formula (II): ##STR2##

Abstract: The present invention concerns a phototackifiable composition useful as a coating on a substrate consisting of an optically clear blend of two or more polymers and a photosensitive compound that forms a strong acid on exposure to actinic radiation. The invention also relates to a process for coating such a composition on a support and toning the image-wise exposed composition on the support.

Abstract: A photoactive compound having formula (I): ##STR1## wherein R is selected from the group consisting of hydrogen or a lower alkyl group having 1-4 carbon atoms and each D is individually selected from the group consisting of a hydrogen or photoactive o-quinonediazide sulfonyl group; subject to the proviso that at least two of the four D's in formula (I) are photoactive o-naphthoquinonediazide sulfonyl moieties.

Abstract: A positive photoresist of the type containing an alkali-soluble novolac resin and a quinone diazide sensitizer contains a dye of the general formula: ##STR1## wherein R' is lower alkyl, R" is H, alkyl or CO.sub.2 -alkyl, alkyl-CO.sub.2 -alkyl or alkyl-CO.sub.2 -(C.sub.1 -C.sub.3 alkyl-O).sub.n -alkyl (n=1-3) and wherein said dye is compatible with the novolac resin/quinone diazide formulation to at least 0.1 phr. The dye reduces reflective notching. Preferably the photoresist also contain a nitro naphthol dye to reduce the effects of I-Line radiation.

Abstract: The invention relates to a photosensitive mixture which essentially contains an ester or an amide of a 1,2-naphthoquinonediazide sulfonic or carboxylic acid as the photosensitive compound, a phenolic resin which is soluble in aqueous-alkaline solutions and insoluble in water as the binder, and an additional speed enhancer, which corresponds to the general formula ##STR1## where X denotes a single bond, CH.sub.2, SO.sub.2, S, CO, C(CH.sub.3).sub.2, CHCC1.sub.3 or ##STR2## Biphenyldiol-(4,4'), bis-(4-hydroxyphenyl)-ketone, 2,2-bis-(4-hydroxy-phenyl)-propane or bis-(4-hydroxyphenyl)-sulfone are described as suitable compounds. The mixture is employed as photosensitive layers in recording materials suitable for the production of printing forms.The invention provides for an increased photospeed, without any disadvantages occurring in respect of the copying or printing behavior.

Abstract: A positive photoresist composition is disclosed, comprising (a) from 50 to 99 parts by weight of a polyhydric phenol compound which is a condensation product between a mixed phenol comprising o-cresol and at least one of 2,5-dimethylphenol and 3,5-dimethylphenol at a molar ratio of from 95/5 to 5/95 and an aldehyde and (b) from 1 to 50 parts by weight of a quinone diazide compound. The composition is excellent in sensitivity, resolving power, heat resistance, and resistance to dry etching.

Abstract: A chemical mat film having good writability and printability is disclosed which includes a transparent film, a chemical mat layer provided on one or both sides of the transparent film and containing finely divided solid particles which provide surface roughness, and an overcoat layer formed of a polymeric material and provided over the surface of the chemical mat layer, the overcoat layer having a surface roughness which is substantially coincident with that of the chemical mat layer. The chemical mat film may be used as a substrate of a photosensitive film for supporting a photosensitive layer thereon.

Abstract: Disclosed is a photosensitive quinone diazide compound for the preparation of a two component positive working photosensitive electrodeposition composition. As the photosensitive group is grafted on a polyurethane, the photosensitive compound thus synthesized has good flexibility and good compatability with acrylic resin. The electrodeposition composition also has good adhesion to the metal base plate when it is coated thereon by electrodeposition means.

Abstract: A photosensitizer comprising a diazo ester of benzolactone ring compound, such as phenolphthalein or cresolphthalein as the backbone, where at least one of the hydroxy groups on the benzolactone ring compound has been esterified with diazo-sulfonyl chloride consisting of 60 to 100 mole % 2,1,4 or 2,1,5-diazo sulfonyl chloride or a mixture thereof, and a photoresist comprising an admixture of the photosensitizer, which is present in the photoresist composition in an amount sufficient to uniformly photosensitize the photoresist composition; a water insoluble, aqueous alkali soluble novolak resin, the novolak resin being present in the photoresist composition in an amount sufficient to form a substantially uniform photoresist composition and a suitable solvent.

Abstract: Structures of high resolution in the near UV range and of high sharpness of edge and steepness of edge can be obtained by means of positive photoresists containing, in an organic solvent, in each case essentially at least(a) an alkali-soluble resin(b) a 1,2-naphthoquinone-diazide-5-sulfonyl ester of a trihydroxybenzene isomer(c) an aromatic hydroxy compoundand also, if appropriate, further customary additives, and in which the result of component (b) is to give an absorption coefficient of at least 0.5 .mu.m.sup.-1 for the photobleachable absorption, and component (c) is present in a concentration of 15-30% by weight, relative to the total solids content.

Abstract: A process of developing an image-wise exposed photoresist-coated substrate comprising: coating a substrate with a positive working photoresist comprising an admixture of an alkali soluble binder resin and photoactive formula (V): ##STR1## wherein R.sub.2 is selected from the group consisting of an OD group, a halide group, a lower alkyl group having 1 or 4 carbon atoms and a lower alkoxy group having 1 to 4 carbon atoms, and D is selected from the group consisting of o-naphthoquinone diazide sulfonyl group and hydrogen; with the proviso that at least four D's are o-naphthoquinone diazide sulfonyl groups; subjecting the coating on the substrate to an image-wise exposure of radiation; and subjecting the image-wise coated substrate to a developing solution to remove the exposed areas of the radiation-exposed coating, leaving a positive image pattern.

Abstract: A photosensitive composition comprising (a) a 1,2-naphthoquinone-2-diazido-4-sulfonic acid ester compound, (b) alkali-soluble resin, (c) a halomethyloxadiazole compound which releases halogen free radicals by irradiation with actinic rays and (a) a dye which interacts withthe decomposition product of said halomethyloxydiazole compound and discolors or develops color. The composition exhibits excellent development latitude, light safety, visible-on-exposure characteristic and printing resistance.

Abstract: A radiation-sensitive composition comprising an admixture in a solvent of: at least one alkali-soluble binder resin, at least one photoactive compound and an effective sensitivity enhancing amount of at least one tris (hydroxyphenyl) lower alkane compound; the amount of said binder resin being about 60% to 95% by weight, the amount of said photoactive component being about 5% to about 40% by weight, based on the total solids content of said radiation-sensitive composition.

Abstract: A photosensitive resin composition comprising (A) an alkaline aqueous solution-soluble novolak resin, (B) a photosensitizer obtained by reacting a polyhydroxy compound with 1,2-naphthoquinone-(2)-diazido-5(or 4)-sulfonyl chloride, and (C) an ultraviolet absorber such as 2-(2'-hydroxy-5'-methylphenyl)-benzotriazole, has a strong absorption against a light of a wavelength of 365 nm and is suitable for producing semiconductor elements, etc.

Abstract: A radiation-sensitive resin composition comprising a solution of an alkali-soluble resin and a radiation-sensitive compound in a solvent comprising a monooxymonocarboxylic acid ester. This composition has a high storage stability (i.e., a very small amount of fine particles are formed during storage) and is suited for use as a resist for making integrated circuits.

Abstract: This invention provides an improved negative-working or positive-working, single sheet color proofing method which can accurately reproduce images by using colored, photosensitive layers on substrates which are then overcoated with partially developable adhesive layers. The final construction is useful in predicting the image quality from a lithographic printing process. The partial removal of the adhesive layers cleans out any background stain which may remain from the incomplete removal of the photosensitive layer.

Abstract: A positive type light-sensitive composition is disclosed, comprising an alkali-soluble high-molecular binder and at least one p-iminoquinonediazido-N-sulfonyl compound. This composition can be used for forming a resist for an IC board, a printing plate, a silver-free, image-forming material, etc.

Abstract: A photoresist composition, and a process for using the same are; the composition comprises a polyphenolic resin and a sensitizer effective, when exposed to actinic radiation, to provide alkali solubility to said composition, wherein said resin is represented by the formula (I) or (II): ##STR1## wherein R is a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkaryl group or an aryl group; R' is a silyl group; and n and n'+m are greater than 3. The composition exhibits high thermal and plasmal resistance and good dissolution characteristics.

Abstract: A positive resist composition comprising an aromatic group-containing alkali-soluble resin and a compound having an ammonium salt as skeleton, as the main components.

Abstract: Positive-working photoresist compositions containing 23-27%, based on said composition, of at least one compound of formula (I) ##STR1## wherein one of the substituents X is hydrogen or a group of formula II ##STR2## and the other substituents X are a group of formula II; and 6-11%, based on said composition, of at least one polyhydroxy compound of formula III ##STR3## wherein X is a direct bond, --O--, --S--, --SO.sub.2 --, --CO-- or C(R.sub.6 (R.sub.7)--, and R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently of the other hydrogen, halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or hydroxy, and R.sub.6 and R.sub.7 are each independently of the other hydrogen, --CH.sub.3 or --CF.sub.3.These compositions have particularly good profile contrast and exhibit insignificant fluctuations in line width.

Abstract: A light-sensitive composition is provided comprising (a) an aromatic diazo compound and (b) a cationic dye/borate anion complex.In a preferred embodiment, the cationic dye/anionic borate dye complex is represented by the general formula (I): ##STR1## wherein D.sup.+ represents a cationic dye; and R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be the same or different, each represents an unsubstituted or substituted alkyl group, an unsubstituted or substituted aryl group, an unsubstituted or substituted aralkyl group, an unsubstituted or substituted alkenyl group, an unsubstituted or substituted alkynyl group, an unsubstituted or substituted alicyclic group, or an unsubstituted or substituted heterocyclic group.The aromatic diazo compound can be a nonionic diazo compound.The light-sensitive compound can further comprise a radical-polymerizable unsaturated compound.

Abstract: A resist composition comprising an alkali-soluble resin, a 1,2-quinone diazide compound and a compound of the general formula (I): ##STR1## wherein Z is an oxygen or sulfur atom or a group of the formula: >N--R.sub.4 in which R.sub.4 is a hydrogen atom or an alkyl group; R.sub.1, R.sub.2 and R.sub.3 are the same or different and independently a hydrogen atom, a substituted or unsubstituted alkyl group, a halogen atom, a hydroxyl group, a cyano group or a group of the formula: --OCOR" in which R" is a substituted or unsubstituted alkyl group; and X and Y are independently a cyano group or a group of the formula: ##STR2## --COOR or --CONHR' in R is an alkyl group and R' is a hydrogen atom or an aryl group, which is suitable for the formation of very fine patterns on a substrate having a high reflectance.

Abstract: A positively operating radiation-sensitive mixture comprising a binder which is insoluble in water but soluble or at least swellable in aqueous alkaline solution, and as a photoactive component a polyfunctional .alpha.-diazo-.beta.-keto ester of the general formula I ##STR1## in which R.sup.1 denotes an aliphatic, cycloaliphatic or araliphatic or aromatic radical having 4 to 20 carbon atoms, in which individual CH.sub.2 groups can be replaced by oxygen or sulfur atoms or by ##STR2## or NH groups and/or contain keto groups, X denotes an aliphatic, cycloaliphatic, carbocyclic, heterocyclic or araliphatic radical having 2 to 22 carbon atoms, in which individual CH.sub.2 groups can be replaced by oxygen or sulfur atoms or by the groups --NR.sup.2 --, --C(O)--O--, --C(O)--NR.sup.2 --, --C(O)-- ##STR3## --NR.sup.2 --C(O)--NR.sup.3 --, --O--C(O)--NR.sup.2 --, --C(O)-- ##STR4## or --O--C(O)--O--, or CH groups can be replaced by ##STR5## in which R.sup.2 and R.sup.

Abstract: A positive resist composition comprising a radiation-sensitive component and an alkali-soluble resin and a phenol compound of the formula: ##STR1## wherein R is a hydrogen atom, a lower alkyl group or a phenyl group, R' is an alkyl group or an alkoxy group, and n is a number of 0 to 3, which has well balanced good properties such as sensitivity, resolution, heat resistance and adhesiveness.

Abstract: A positive photosensitive composition for forming lenses, which comprises a polymer, a photosensitive agent, a thermosetting agent and a solvent, wherein said polymer is an alkali-soluble resin, said photosensitive agent is a 1,2-naphthoquinone diazide sulfonate, and said thermosetting agent is a thermosetting agent capable of imparting heat resistance and solvent resistance at the time of forming lenses by heat treatment.