EP-3940747-B1 - NOVEL ETCHING PATTERN FORMING METHOD IN SEMICONDUCTOR MANUFACTURING PROCESS

EP3940747B1EP 3940747 B1EP3940747 B1EP 3940747B1EP-3940747-B1

Inventors

LEE, SU JIN
KIM, GI HONG
LEE, SEUNG HUN
LEE, SEUNG HYUN

Dates

Publication Date: 20260506
Application Date: 20200306

Claims (7)

A method of forming an etching pattern for a silicon or silicon compound layer, the etching pattern being a double-layer structure composed of a photoresist film and a multifunctional organic-inorganic mask film instead of a four-layer structure composed of a photoresist film, an anti-reflective film, a SiON film, and an organic hard mask film formed on a wafer to be etched, the method comprising the steps of: i) primarily forming a multifunctional organic-inorganic mask film by applying a liquid multifunctional organic-inorganic mask film composition containing a solvent, a silicon compound, a crosslinking agent, an additive, and a surfactant and capable of being spin coated onto the wafer to be etched, using a spin coater, at a speed of 100 to 4000 rpm, and then by heating the composition to a temperature of 100°C to 400°C for 20 to 600 seconds, wherein the multifunctional organic-inorganic mask film comprises 20% to 79% by weight of carbon, 20% to 79% by weight of silicon, and 1% to 20% by weight of other elements including oxygen and hydrogen; ii) secondarily forming a photoresist film for pattern formation on the formed multifunctional organic-inorganic mask film; iii) forming a photoresist pattern through exposure and development, wherein a light source for forming the pattern is selected from the group consisting of light sources having wavelengths of 13.5 nm, 193 nm, 248 nm, and 365 nm, and E-beam; and iv) performing dry etching with an etching gas by using the photoresist pattern as a mask to form the pattern for the silicon or silicon compound layer.
The method of claim 1, wherein the etching gas used for the dry etching in step iv) after the pattern is formed is one gas selected from or a gas mixture of at least two selected from the group consisting of: inert gas such as argon or nitrogen; gas having molecules containing at least one fluorine atom; and oxygen gas.
The method of claim 1, wherein the solvent has sufficient solubility for the Si compound and is one selected from or a mixture of at least two selected from the group consisting of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), ethyl 3-ethoxypropionate (EEP), ethyl lactate (EL), cyclohexanone, and gamma butyrolactone (GBL).
The method of claim 1, wherein the Si compound is one selected from or a mixture of at least two selected from the group consisting of poly[dimethylsiloxane-co-(2-(3,4-epoxycyclohexyl)ethyl)methylsiloxane], poly[dimethylsiloxane-co-2-(9,9-bis(4-hydroxyphenyl)fluorene)methylsiloxane], poly(dimethylsiloxane), diglycidyl ether terminated, poly (dimethylsiloxane), bis (hydroxyalkyl) terminated, poly(dimethylsiloxane-co-diphenylsiloxane), dihydroxyterminated, poly(dimethylsiloxane-co-methylhydrosiloxane), trimethylsilylterminated, poly(dimethylsiloxane)-graft-polyacrylate, and poly[dimethylsiloxane-co-methyl(3-hydroxypropyl)siloxane]-graft-poly(ethylene glycol) methyl ether.
The method of claim 1, wherein the crosslinking agent is one selected from or a mixture of at least two selected from the group consisting of tris(2,3-epoxypropyl)isocyanurate), trimethylol methane triglycidyl ether, trimethylol propane triglycidyl ether, triethylol ethane triglycidyl ether, hexamethylolmelamine, hexamethoxymethylmelamine, hexamethoxyethylmelamine, tetramethylol 2,4-diamino-1,3,5-triazine, tetramethoxymethyl-2,4-diamino-1,3,5-triazine, tetramethylol glycoluril, tetramethoxymethylurea, tetramethoxymethyl glycoluril, tetramethoxyethyl glycoluril, tetramethylolurea, tetramethoxyethylurea, and tetramethoxyethyl-2,4-diamino-1,3,5-triazine.
The method of claim 1, wherein the additive is a thermal acid generator (TAG) that releases an acid during heat treatment, and is one selected from or a mixture of at least two selected from the group consisting of pyridinium p-toluenesulfonate, benzoin tosylate, tetrabromocyclohexadiene, 2-methylimidazole, 2-phenylimidazole, Ajicure MY-H, and Fujicure FXR-1030.
The method of claim 1, wherein the surfactant is one selected from or a mixture of at least two selected from the group consisting of anionic, nonionic, cationic, and amphoteric surfactants.

Description

Technical Field The present disclosure relates to a method of forming an etching pattern in a semiconductor manufacturing process. Unlike a conventional method of forming a four-layer structure composed of a photoresist film, an anti-reflective film, a SiON film, and an organic hard mask film on a wafer, as preparation for an etching process, the method according to the present disclosure is an innovative etching pattern forming method capable of implementing the same etching pattern as is formed by the conventional method, using a double-layer structure composed of a photoresist film and a multifunctional organic-inorganic mask film. Background Art With the recent increase in demand for semiconductors, there is an urgent need for efforts to increase productivity efficiency by simplifying manufacturing processes along with large-scale investments in semiconductor manufacturing equipment. In response to the need for the realization of fine patterns due to the miniaturization and increased integration of semiconductor devices, a method has been proposed in which a high-resolution photoresist, an anti-reflective film for preventing pattern defects attributable to diffuse reflection of the photoresist, and an inorganic film and an organic hard mask film for increasing etch selectivity are sequentially formed on a wafer. This known method is widely used as a coating film forming technique for forming an etching pattern in current semiconductor manufacturing.US 2017/154766 A1 relates to a silicon-containing condensate, a composition containing the same for forming a silicon-containing resist under layer film, and a patterning process using the same. JP 2017 068261 A relates to a method for producing a refined chemical liquid for lithography and a method for forming a resist pattern. US 2017/315445 A1 relates to a resist underlayer film-forming composition for a lithography process which has a characteristic of enabling wafer surface planarization after film formation due to excellent planarization performance on a substrate with a level difference and good embeddability in a fine hole pattern. US 2016/349616 A1 relates to a semiconductor device production composition and a pattern formation method. Typically, a four-layer structure composed of a photoresist film, an anti-reflective film, a SiON film, and an organic hard mask film is formed on a wafer. The formation of each coating film involves multiple processes ranging from a minimum of two processes to a maximum of six processes, including coating, heat treatment, exposure, development, and the like. This means that a total of 8 to 24 processes are required to form the four-layer structure. When any one of the four coating films can be eliminated, or any one of the two to six processes for forming each coating film can be omitted, not only production time and cost but also manufacturing equipment investment and maintenance costs can be dramatically reduced. To this end, ongoing efforts have been made to combines some of the physical properties of each coating film, but these efforts have yet to yield the desired results due to the difficulty in satisfying the physical properties required for each coating film. Although there are several inventions and papers discussing a material that combines the properties of an anti-reflective film and an inorganic film represented by a SiON film, this material technique is currently in very limited use. This is because, due to the conflicting properties of the organic anti-reflective film and the silicon inorganic film, the material cannot function as the anti-reflective film but can function as only the inorganic film. Conversely, it cannot function as the inorganic film but can function as only the anti-reflective film. In addition, it has been impossible to integrate an inorganic film such as a SiON film and an organic hard film mainly composed of carbon due to different etching ratios for oxygen or fluoride gas, attributable to different physical properties thereof. One possible approach is to increase the thickness of an organic hard film and to perform deeper etch. However, this cannot be regarded as an improved method because it essentially requires the use of an anti-reflective film and an inorganic film. Another possible approach is to increase the thickness of an inorganic film. However, since the inorganic film is a glass film, when the inorganic film becomes thicker, the inorganic film is likely to crack during heat treatment or to be non-uniform in the thickness thereof. Thus, it is recommendable to increase the thickness of the inorganic film to the extent that it is possible to replace the organic hard film. As a solution to the above problems of the related art, the inventors of the present application have developed a pre-etching coating technology by which one innovative coating film can replace conventional three coating films including an anti-reflective film, an inorganic film, and an organic film by e