阅读说明：本技术 在半导体制造工艺中用于形成硅或硅化合物图案的新方法 (Novel method for forming silicon or silicon compound pattern in semiconductor manufacturing process ) 是由 李秀珍 金起洪 李昇勋 李昇炫 于 2020-01-17 设计创作，主要内容包括：本发明的目的在于提供一种在半导体制造工艺中用于实现纵横比大的微细硅图案的工艺,涉及一种为了形成微细硅图案,且为了清除残留在图案下部的有机碳膜不纯物质及由烟气产生的不纯物质而进行清洗工程,以形成所希望的图案而不发生图案被升起的新的清洗方法,具有提供细微图案形成方法的效果。(The present invention provides a process for forming a fine silicon pattern having a large aspect ratio in a semiconductor manufacturing process, and relates to a novel cleaning method for forming a desired pattern without raising the pattern by performing a cleaning process for forming a fine silicon pattern and for removing impurities of an organic carbon film and impurities generated by fumes remaining under the pattern.)

1. A method of forming a silicon or silicon compound pattern, for a process of depositing a layer of polycrystalline material or other compound in the presence of a silicon oxide pattern in a silicon or silicon compound layer in a semiconductor manufacturing process, comprising:

i) sequentially laminating an organic film and an inorganic film on the patterned silicon oxide, coating a photoresist for forming a pattern, and exposing and developing to form a photoresist pattern;

ii) a step of performing etching by dry etching with a gas capable of etching using the mask;

iii) a step of cleaning the pattern wafer on which the organic film is left with a cleaning solution before depositing a polycrystalline material layer or other compound layer in order to prevent lifting due to impurities generated in the etching process; and

iv) a step of dry etching is carried out after deposition of the polycrystalline material layer or the other compound layer.

2. The method of forming a silicon or silicon compound pattern according to claim 1, wherein the step of cleaning with a cleaning liquid is performed by,

the wafer is spun at a speed of 0to 1,000rpm, sprayed at a speed of 1 to 200mL/s for 1 to 200 seconds, set for 0to 180 seconds, and then spin-dried.

3. The method of forming a silicon or silicon compound pattern according to claim 2,

the cleaning liquid is ejected in an ejection amount of 20 to 300 mL.

4. The method of forming a silicon or silicon compound pattern according to claim 3,

the cleaning liquid is ejected in an ejection amount of 40 to 300 mL.

5. The method of forming a silicon or silicon compound pattern according to claim 4,

the cleaning liquid is ejected in an ejection amount of 50 to 300 mL.

6. The method of forming a silicon or silicon compound pattern according to claim 1,

the method of laminating the organic film and the inorganic film on the object to be etched is a method of coating or a method of chemical or physical deposition.

7. The method of forming a silicon or silicon compound pattern according to claim 6,

the carbon content of the organic film laminated on the etching object is 30% to 100%.

8. The method of claim 1, wherein the light source for forming the pattern has a wavelength of 13.5nm, 198nm, 248nm, or 365nm and comprises an electron beam.

9. The method of forming a silicon or silicon compound pattern according to claim 1,

the gas used for dry etching after patterning is an inert gas selected from the group consisting of argon and nitrogen; a gas composed of molecules containing 1 or more fluorine atoms; or oxygen or a mixture of two or more gases.

10. The method of forming a silicon or silicon compound pattern according to claim 1,

the cleaning solution uses a cleaning solution composed of 1 to 100% by weight of a substance that can clean the polymer residue, 0to 99% by weight of a solvent, 0to 3% by weight of a surfactant, 0to 10% by weight of an alkaline compound.

11. The method of forming a silicon or silicon compound pattern according to claim 10,

the polymer residue is washed with one or more selected from ethanol solvent, amide solvent, ketone solvent, ester solvent and hydrocarbon solvent.

12. The method of forming a silicon or silicon compound pattern according to claim 10,

the alkaline compound is one or more of amines and ammonium hydroxide.

Technical Field

The present invention relates to a novel method for forming a silicon or silicon compound pattern in a semiconductor manufacturing process, which includes a cleaning method for preventing pattern Lifting (Lifting) using a cleaning liquid in a process for forming a fine pattern using an organic carbon film in order to remove foreign substances remaining at the bottom when polymer dry etching is performed.

Background

Recently, as semiconductor devices are miniaturized and integrated, realization of fine patterns is required. As a method for forming such a fine pattern, it is effective to miniaturize a photoresist pattern by development of exposure equipment or introduction of an additional process.

In a process for manufacturing a semiconductor, a semiconductor substrate has been patterned using an i-line (i-line) light source having a wavelength of 365nm in the past, but in order to form a finer pattern, a light source of a smaller wavelength band is required.

Actually, starting from KrF (248nm), technologies of lithography (lithograph) using ArF (198nm), EUV (extreme ultraviolet, 13.5nm) light sources and overlay exposure (double patterning lithography) of ArF lithography have been developed, and are now being commercialized or under commercialization, and finer wavelengths can be realized using these technologies.

When a conventional photoresist having a thickness as thick (>500nm) is used to realize a fine pattern with a large aspect ratio, the pattern aspect ratio of the photoresist becomes high and pattern collapse occurs, which is an obstacle to realizing a pattern with a large aspect ratio. In connection with pattern collapse, if the thickness of the photoresist is reduced, the function as a mask for a substrate (substrate) cannot be sufficiently performed in a subsequent Dry etching (Dry etch) process, and thus a pattern having a depth as deep as required for realizing the pattern cannot be produced for these reasons.

In order to solve such a problem, a process using an organic carbon film material called a hard mask (hardmak), such as an amorphous carbon film layer (ACL), spin carbon (SOC), or spin hard mask (SOH), is being performed.

A method of forming a pattern by selective dry etching using plasma after forming a film for etching to be performed is employed.

Briefly looking at the process sequence, an SOC layer as an organic carbon film was coated on a silicon oxide substrate layer, a SiON layer as an inorganic film was deposited by chemical vapor deposition, and a photoresist was coated thereon and exposed to light for patterning. After etching the SiON layer with halogen plasma using the patterned photoresist, the organic carbon film layer is etched with oxygen plasma, and then the Oxide layer as a substrate layer is etched with halogen plasma. After etching the "oxide layer (a film)" with halogen plasma, a "polycrystalline material layer (Poly layer)" or "other compound layer (B film)" is deposited on the pattern by chemical vapor deposition, and then the final substrate layer is etched with halogen plasma.

In the process of introducing a hard mask in order to realize a miniaturized pattern, the aspect ratio of the pattern becomes higher as the pattern tends to be miniaturized, and thus a problem is occurring in the pattern that can be realized by the dry etching process. There are problems in that the residue of the organic carbon film polymer and the foreign matter generated from the fumes, which occur in the dry etching process, are lifted up when the subsequent film process is performed.

The present inventors have studied new process development to solve the problems occurring in the conventional process, and as a result of the research, have developed a technology capable of forming a finer pattern by adding a wet cleaning process after Dry etching (Dry etch).

Disclosure of Invention

Technical problem to be solved

The present invention relates to a novel method for forming a hard mask pattern in a semiconductor manufacturing process, which includes a novel cleaning method for removing foreign substances remaining at the bottom when polymer dry etching is performed to prevent the pattern from being lifted in a process for forming a fine pattern using an organic carbon film.

Means for solving the problems

The present invention relates to a method for forming a pattern using a cleaning process, which uses a cleaning solution in order to form a desired pattern and to solve a problem of rising due to impurities remaining under the pattern after a silicon or silicon compound etching process.

More specifically, in an etching process of an oxide, silicon, or silicon compound layer in a semiconductor manufacturing process, an organic film and an inorganic film are sequentially stacked in an appropriate thickness on an object to be etched, and first, an organic carbon film layer containing a large amount of carbon is coated, then, a SiON layer is deposited by a chemical vapor deposition method, and then, a photoresist is coated thereon to perform patterning. After etching the SiON layer with halogen plasma using the patterned photoresist, the organic carbon film layer is etched with oxygen plasma, and then the oxide layer as a substrate layer is etched with halogen plasma. After etching the oxide layer with a halogen plasma, a layer of polycrystalline material (Poly layer) or other compound is deposited over the pattern by chemical vapor deposition, and the final substrate layer is then etched with a halogen plasma to create the pattern to be formed.

In the case of forming a fine pattern by dry etching after depositing an oxide or silicon compound layer after coating an organic carbon film in order to form a fine pattern, polymer foreign substances due to the organic carbon film layer and residues due to fumes remain under the pattern, which causes problems such as being lifted when depositing an inorganic film.

In order to solve the problem of occurrence of such lifting, foreign substances remaining at the lower portion of the pattern are removed by performing a cleaning process using a new cleaning liquid to form a desired fine pattern.

Among them, the organic carbon film means a film material having a carbon content of 30% to 100% which can be coated on a wafer by spin coating or chemical physical deposition.

The spin-on thickness of the spin-coatable SOC in the organic carbon film layer is not particularly limited, but may beToAnd the baking process may be performed at a temperature of 150 to 400 c for 1 to 5 minutes.

The layer that can be formed by chemical or physical deposition methods can be plasma-applied in a deposition apparatus at a pressure of 0.01 to 10torr to form a layerToIs formed by the thickness of (a).

The cleaning solution is composed of 1 to 100% by weight of a substance that can clean polymer residues, 0to 99% by weight of a solvent, 0to 3% by weight of a surfactant, and 0to 10% by weight of an alkaline compound.

As the substance capable of washing the polymer residue, one or more selected from ethanol-based solvents, amide-based solvents, ketone-based solvents, ester-based solvents and hydrocarbon-based solvents can be used.

The solvent to be used is not particularly limited as long as it does not dissolve the organic carbon film and the inorganic film pattern, and a solution containing a general organic solvent may be used.

The surfactant may be selected from anionic, nonionic, cationic, amphoteric surfactants, singly or in combination of mixtures thereof.

Alternatively, a basic compound selected from amines and ammonium hydroxide may be used.

The cleaning method of the cleaning liquid is composed of a process of spraying at a speed of 1 to 200mL/s for 1 second or more, setting for 0 second or more, and then spin-drying (spin dry) in a state that the wafer is rotated at a speed of 0to 1,000 rpm.

The polycrystalline material capable of being formed by a chemical or physical deposition methodThe layer (Poly layer) or other compound layer may be deposited using a plasma in a deposition apparatus at a pressure of 0.01 to 10torr to form a layerToIs formed by the thickness of (a).

ADVANTAGEOUS EFFECTS OF INVENTION

By the method of forming a fine pattern by the novel cleaning method according to the present invention, an organic carbon film layer and an SiON layer are formed on a silicon oxide substrate layer and first dry etching is performed to form a desired pattern, and a polycrystalline material layer (Poly layer) or other compound layer is deposited by a chemical vapor deposition method and second dry etching is performed to form a pattern.

When depositing a polycrystalline material layer (Poly layer) or other compound layer, a pattern defect occurs due to the lifting of organic carbon film residue remaining at the lower portion of the pattern at the first dry etching and residue caused by fumes. In order to solve this problem, a cleaning process is added after the first dry etching to remove residues remaining on the lower layer of the pattern.

The problem of pattern lifting during deposition of a polycrystalline material layer (Poly layer) or other compound layer is solved by removing residues remaining on the lower layer of the pattern, thereby enabling formation of a silicon and silicon compound pattern having a desired high aspect ratio.

Best mode for carrying out the invention

The present invention will be described in more detail below.

The present invention relates to a novel cleaning method in a semiconductor manufacturing process, which performs a cleaning process to form a desired pattern without rising in order to remove organic carbon film residue remaining under the pattern and residue generated from fumes in order to form a fine silicon pattern.

The method for forming a fine pattern by a novel cleaning method of the present invention forms a pattern by the following steps. The steps are as follows: forming an organic carbon film layer on the substrate layer, depositing a SiON layer by using a chemical vapor deposition method, coating photoresist on the SiON layer, and exposing the SiON layer to form a mask; a step of etching a pattern to be formed by performing first dry etching using the mask; cleaning the substrate with a cleaning liquid; and a step of dry etching for the second time after depositing a polycrystalline material layer (Poly layer) or other compound layer on the substrate by chemical vapor deposition.

The method for forming the carbon film layer with the carbon content of 30-100% can be spin coating, chemical or physical deposition.

The spin-on thickness of the spin-coatable SOC in the organic carbon film layer is not particularly limited, but may beToAnd the baking process may be performed at a temperature of 150 to 400 c for 1 to 5 minutes.

The SiON layer capable of being formed by the chemical or physical deposition method may be formed in a deposition apparatus using plasma at a pressure of 0.01 to 10torr toToIs formed by the thickness of (a).

The cleaning solution is composed of 1 to 100% by weight of a substance capable of cleaning polymer impurities, 0to 99% by weight of a solvent, 0to 3% by weight of a surfactant, and 0to 10% by weight of an alkali compound.

As the substance capable of removing the polymer impurities, one or more selected from the group consisting of ethanol-based solvents, amide-based solvents, ketone-based solvents, ester-based solvents and hydrocarbon-based solvents can be used.

The solvent to be used as an alternative is not particularly limited as long as it does not dissolve the organic carbon film and the inorganic film pattern, but a solution containing a general organic solvent may be used.

The surfactant may be a surfactant selected from anionic, nonionic, cationic, amphoteric surfactants, singly or in combination.

Alternatively, a basic compound selected from amines and ammonium hydroxide may be used.

The cleaning method of the cleaning liquid is realized by the following processes. In the case of rotating the wafer at a speed of 0to 1,000rpm, the wafer is ejected at a speed of 1 to 200mL/s for 1 second or more, stopped for 0 second or more, and then spun dry (spin dry).

The polycrystalline material layer (Poly layer) or other compound layer capable of being formed by a chemical or physical deposition method may be formed in a deposition apparatus using plasma at a pressure of 0.01 to 10torr to form a polycrystalline material layerToIs formed by the thickness of (a).

Specific contents related to the objects and technical constitutions of the present invention and effects thereof will be clearly understood by referring to the following detailed description of preferred embodiments of the present invention.

The spin-on thickness of the spin-coatable SOC in the organic carbon film layer is not particularly limited, but may beToAnd the baking process may be performed at a temperature of 150 to 400 c for 1 to 5 minutes.

The SiON layer capable of being formed by the chemical or physical deposition method may be formed in a deposition apparatus using a plasma at a pressure of 0.01 to 10torr toToIs formed by the thickness of (a).

Patterning is performed using the formed mask, and first dry etching is performed using an etching gas that can etch the deposited film.

Then, the substrate subjected to the first dry etching is treated with a cleaning solution.

The cleaning liquid used in the cleaning process is composed of 1 to 100% by weight of a substance that can clean polymer residues, 0to 99% by weight of a solvent, 0to 3% by weight of a surfactant, and 0to 10% by weight of an alkaline compound.

The cleaning method of the cleaning liquid is realized by the following processes. The wafer is rotated at a speed of 0to 1,000rpm, and sprayed at a speed of 1 to 200mL/s for 1 second or more, set for 0 second or more, and then spin-dried (spin dry).

Then, a polycrystalline material layer (Poly layer) or other compound layer that can be formed by a chemical or physical deposition method is deposited on the substrate. The Poly layer may be deposited in the deposition apparatus using a plasma at a pressure of 0.01 to 10torrToIs formed by the thickness of (a).

A second dry etching is performed using an etching gas that can etch the deposited film to complete the film pattern. And then cleaned with a cleaning liquid to prevent a lift-off phenomenon and complete a desired pattern.

The preferred embodiments of the present invention have been described in detail.

Preferred embodiments of the present invention and comparative examples are described below. However, the following examples are merely one preferred embodiment of the present invention, and the present invention is not limited to the following examples.

Detailed Description

Examples 1 to 10 and comparative examples 1 to 2

Example 1

Spin On Carbon (SOC) layer as an organic carbon film is coated on the patterned substrate layerThen performing a baking process at a temperature of 400 deg.C for 3 minutes by chemical vapor deposition method to obtainAfter the deposition of a SiON layer as inorganic film in thicknessA resist for KrF was thickness-coated, and then exposed at 24mj using a nikon 204B KrF exposure equipment to form a mask having a pattern with a size of 200 nm. The film deposited using the formed mask was dry-etched with an etching gas for the first time to an oxide layer as a substrate layer, and then the substrate subjected to the first dry-etching was coated with a cleaning solution containing 80% of isopropyl alcohol, 17.9% of ethylene glycol, 2% of tetraethylammonium hydroxide, and 0.1% of polyoxyethylene lauryl ester at the spray amounts shown in table 1, and then a chemical vapor deposition method was used to form a filmThe second dry etch is performed after the polycrystalline material layer is thickly deposited, thereby completing the pattern formation process.

Examples 2 to 10

The process was performed in the same manner as in example 1 except that the process was performed in accordance with the ejection amount application described in table 1 to complete the pattern forming process.

Comparative examples 1 to 2

The process was performed in the same manner as in example 1 except that the process was performed in accordance with the spray amount application described in table 1 to complete the pattern forming process.

A pattern forming process was completed by performing the process in the same manner as in example 1, except that the process of applying the cleaning liquid by spin coating as described in table 1 was not performed.

Determination of characteristics

The presence or absence of lift was evaluated for the above examples 1 to 10 and comparative examples 1 to 2, and the results thereof were expressed as the presence or absence of lift evaluation values. The criterion of the presence or absence of the rise evaluation value is as follows.

< evaluation value of presence or absence of lift >

0: lift occurs 100%

1: 90% rise occurs

2: rising occurs 80%

3: 70% rise occurs

4: 60% rise occurs

5: 50% rise occurs

6: 40% rise occurs

7: 30% rise occurs

8: 20% rise occurs

9: rising occurs at 10%

10: 0% rise occurs

[ TABLE 1 ]

As shown in table 1 above, first, in comparative examples 1 to 2, the rise evaluation value was 0to 1 in the case where the ejection volume was 0to 10mL, and very poor results were shown.

Second, in examples 1 to 2, in the case where the ejection volume was 20 to 30mL, the rise occurrence evaluation value was 4 to 6, showing desirable results.

Third, in embodiment 3, in the case where the ejection volume was 40mL, the rising evaluation value was 8, and a more preferable result was shown.

Fourth, in examples 4 to 10, in the case where the ejection volume was 50 to 300mL, the evaluation value of presence or absence of occurrence of lift was 10, and the most preferable results were shown.