JP6271775B2 - Semiconductor device manufacturing method and chemical solution - Google Patents

Description

  FIELD Embodiments described herein relate generally to a method for manufacturing a semiconductor device and a chemical solution used therefor.

  In a manufacturing process of a semiconductor device in which a fine structure is formed, a semiconductor substrate (object to be processed) may be processed with a liquid such as a cleaning liquid. After the liquid treatment, when the surface of the semiconductor substrate is dried, a fine structure formed on the semiconductor substrate may collapse due to the surface tension of the liquid attached to the surface of the semiconductor substrate. In particular, when the pattern is miniaturized and the aspect ratio of the structure is increased, the pattern collapse tends to occur when the semiconductor substrate is dried.

JP 11-294948 A JP 2008-130585 A JP-A-9-190996 JP 2008-10638 A JP 2013-42093 A JP 2013-16699 A

  Provided are a method for manufacturing a semiconductor device capable of suppressing pattern collapse when a semiconductor substrate after liquid processing is dried, and a chemical solution used therefor.

  The method for manufacturing a semiconductor device of this embodiment includes a step of attaching a first liquid to the surface of a semiconductor substrate, and a step of replacing the first liquid with a solution in which a deposited substance is dissolved in a second liquid. Have. A step of evaporating the second liquid to deposit a deposited substance on the surface of the semiconductor substrate; and a step of changing the deposited substance from a solid to a gas by removing pressure and / or heating.

The precipitated substance includes at least one substance selected from the substances represented by formulas A1 to A4 and B1 to B5 shown below,
In the substances represented by the formulas A1, A4, B1, B3, and B5, one of groups bonded to adjacent positions is a carboxyl group, and the other includes any of a carboxyl group, a hydroxy group, and an amino group.

（式Ａ１、Ａ２、Ａ３、Ａ４中、Ｘ^１、Ｘ^２及びＸ^３は、それぞれ独立して、ヒドロキシ基（−ＯＨ）、カルボキシル基（−ＣＯＯＨ）、アミノ基（−ＮＨ_２）、アミド基（−ＣＯＮＨ_２）、ニトロ基（−ＮＯ_２）、メチルエステル基（−ＣＯＯ−ＣＨ_３）の何れかを示す。）

(In formulas A1, A2, A3 and A4, X ¹ , X ² and X ³ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH ₂ ), an amide group, (Indicates any one of (—CONH ₂ ), nitro group (—NO ₂ ), and methyl ester group (—COO—CH ₃ ).)

（式Ｂ１、Ｂ２、Ｂ３、Ｂ４及びＢ５中、Ｘ^１、Ｘ^２、Ｘ^３及びＸ^４は、それぞれ独立して、ヒドロキシ基（−ＯＨ）、カルボキシル基（−ＣＯＯＨ）、アミノ基（−ＮＨ_２）、アミド基（−ＣＯＮＨ_２）、ニトロ基（−ＮＯ_２）、メチルエステル基（−ＣＯＯ−ＣＨ_３）、メトキシ基（−ＯＣＨ_３）、エトキシ基（−ＯＣＨ_２ＣＨ_３）、プロポキシ基（−ＯＣＨ_２ＣＨ_２ＣＨ_３）の何れかを示す。）

(In formulas B1, B2, B3, B4 and B5, X ¹ , X ² , X ³ and X ⁴ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH _2), amido (-CONH _2), a nitro group _(-NO 2), a methyl ester group _(-COO-CH 3), methoxy group (-OCH _3), an ethoxy group _(-OCH 2 _CH 3), propoxy (Indicates any one of —OCH ₂ CH ₂ CH ₃ )

4 is a flowchart illustrating a method for manufacturing a semiconductor device according to the embodiment. The longitudinal cross-sectional view which showed typically the structure of each middle process in the manufacturing method of the semiconductor device which concerns on embodiment Flow chart illustrating the details of the drying process Longitudinal sectional view schematically showing the structure of each intermediate state in the drying process

  Hereinafter, embodiments will be described with reference to the drawings. The drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like do not necessarily match those of the actual one. Even in the case of representing the same part, the dimensions and ratios may be represented differently depending on the drawings. Also, the vertical and horizontal directions also indicate relative directions when the circuit formation surface side of the semiconductor substrate described later is up, and do not necessarily match the direction based on the gravitational acceleration direction. Note that, in the present specification and each drawing, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

(Embodiment)
Embodiments will be described below with reference to FIGS.
FIG. 1 is a flowchart illustrating the method for manufacturing a semiconductor device according to this embodiment. FIG. 2A to FIG. 2C are diagrams for illustrating the method for manufacturing the semiconductor device according to the embodiment, and are longitudinal sections schematically showing the structure of each intermediate process in the method for manufacturing the semiconductor device. FIG. FIG. 3 is a flowchart illustrating in detail the content of the drying process in the method of manufacturing a semiconductor device according to this embodiment. FIG. 4A to FIG. 4D are diagrams for illustrating in detail the drying process in the method for manufacturing a semiconductor device according to the present embodiment, and schematically show the structure of each intermediate state in the drying process. It is a longitudinal cross-sectional view.

  First, as shown in FIGS. 1 and 2A, a semiconductor substrate 50 is prepared (S11). Examples of the semiconductor substrate 50 include various substrates such as a silicon substrate, an SOI (Silicon on Insulator) substrate, an SiC substrate, a substrate composed of a plurality of components including a silicon element, a sapphire substrate, a compound semiconductor substrate, a plastic substrate, and a glass substrate. Can be used. Further, a semiconductor substrate 50 having various insulating films, conductor films, or laminated films thereof formed on the surface may be used. Further, a structure formed of an insulating film, a conductive film, or a laminated film thereof is formed on the surface. For example, a semiconductor substrate 50 in which the surface of the structure is covered with an insulating film may be used.

  A film to be etched 52 is formed on the semiconductor substrate 50. The etched film 52 is formed of, for example, an insulating film. For example, a silicon oxide film can be used as the insulating film. As the film to be etched 52, various organic substances, inorganic substances, insulating films, conductor films, etc., or a laminated film thereof can be used.

  Examples of the etching target film 52 include silicon-based materials such as silicon oxide, silicon nitride, polycrystalline silicon, and single-crystal silicon, metal-based materials such as titanium nitride, tungsten, ruthenium, tantalum nitride, and tin, and a combination of these materials. Can be used.

  For example, the film to be etched 52 may have a film structure used for a memory gate of a NAND-type nonvolatile semiconductor memory device. For example, a gate insulating film (for example, silicon oxide film), a first polysilicon film, a silicon oxynitride film, a second polysilicon film, a barrier metal film (for example, tungsten nitride), a metal film (for example, tungsten) Alternatively, a film in which a cap insulating film (for example, a silicon nitride film) or the like is laminated may be formed as the etching target film 52.

  An etching mask 54 is formed on the etching target film 52. As the etching mask 54, for example, a resist film pattern formed by a lithography method can be used. Further, the etching mask 54 may be a hard mask formed of, for example, a silicon oxide film, a silicon nitride film, polysilicon, carbon, or other materials instead of the resist film. The hard mask can be formed by patterning using, for example, a lithography method and an RIE (Reactive Ion Etching) method. The etching mask 54 may be formed by a sidewall transfer method in which a fine pattern is formed using a sidewall pattern formed on the side surface of the core material, for example.

  The etching mask 54 is formed using a material having an etching selectivity with respect to the etching target film 52. For example, the etching mask 54 extends in the front-depth direction (first direction) in FIG. 2A and has a predetermined width and a predetermined interval in the left-right direction (second direction orthogonal to the first direction) in FIG. Are formed in a line and space shape in parallel. In addition, the etching mask 54 may be a hole or pillar type pattern, for example, a cylinder capacitor pattern of a DRAM (Dynamic Random Access Memory).

  Next, as shown in FIGS. 1 and 2B, the etching target film 52 is etched using the etching mask 54 as a mask (S12). For the etching, for example, dry etching by the RIE method can be used. Wet etching can be used instead of dry etching. In this embodiment, an example using dry etching by the RIE method is shown. In dry etching by the RIE method, anisotropic conditions or isotropic conditions may be used. In this embodiment, an example using anisotropic conditions is shown.

  In this etching, the etching target film 52 is etched using the etching mask 54 as a mask. By this etching, the shape of the etching mask 54 is transferred to the etching target film 52, and the structure 56 is formed. The structure 56 extends, for example, in the front-depth direction (first direction) in FIG. 2B, and has a predetermined width and a predetermined interval in the left-right direction (second direction orthogonal to the first direction) in the drawing. Are formed in a line and space shape in parallel.

  Next, the etching mask 54 is removed. As shown in FIG. 2B, foreign substances 58 such as impurities including various inorganic substances, organic substances, metals, etc., etching residues, deposits, and particles adhere to the surfaces of the semiconductor substrate 50 and the structure 56. There is a case.

  Next, as shown in FIGS. 1 and 2C, the semiconductor substrate 50 subjected to the etching is washed (S13). Various washing solutions can be used for washing. For example, sulfuric acid hydrogen peroxide water cleaning (SPM cleaning; Sulfuric Acid Hydrogen Peroxide Mixture), ammonia hydrogen peroxide water cleaning (APM cleaning; Ammonium Hydrogen Peroxide Mixture), hydrochloric acid hydrogen peroxide water cleaning (HPM cleaning; Hydrochloric Acid Hydrogen Peroxide Mixture) ), Various cleaning solutions such as diluted hydrofluoric acid cleaning (DHF cleaning; Diluted Hydrofluoric Acid) can be used. Thereby, the foreign material 58 containing organic substance, a metal, a particle, etc. can be removed.

  In the cleaning, for example, a method of immersing the semiconductor substrate 50 in a bath filled with the cleaning solution 60 or a spin that places the semiconductor substrate 50 on a spinner device and supplies the cleaning solution 60 to the surface of the rotating semiconductor substrate 50. A cleaning method or the like can be used. After the above cleaning process, the cleaning solution 60 adheres to the surface of the semiconductor substrate 50.

  Next, as shown in FIGS. 1 and 2D, the surface of the semiconductor substrate 50 is rinsed with a rinsing liquid 62. As the rinsing liquid 62, for example, deionized water (DIW) can be used. By the rinsing process, the cleaning solution 60 adhering to the semiconductor substrate 50 can be removed by replacing it with the rinsing liquid 62. The treatment with the rinsing liquid 62 is performed, for example, by immersing the semiconductor substrate 50 in a bath filled with the rinsing liquid 62 or by placing the semiconductor substrate 50 on a spinner device and supplying the rinsing liquid 62 to the surface of the rotating semiconductor substrate 50. Or the like can be used.

  The space between the adjacent structures 56 on the surface of the semiconductor substrate 50 is filled with the cleaning solution 60 or the rinsing liquid 62 from the above treatment with the cleaning solution 60 to the rinsing process, and the drying process described below is performed from this state. .

  Next, as shown in FIG. 1, the semiconductor substrate 50 is dried (S14). Detailed procedures of the drying process are shown in FIGS. The contents of the drying process of the semiconductor device manufacturing method according to the present embodiment will be described in detail below with reference to FIGS.

  First, as shown in FIG. 3 and FIG. 4A, the replacement liquid 70 is supplied onto the semiconductor substrate 50 in which the structure 56 is formed on the surface and the rinsing liquid 62 is filled at least between the structures 56. (S21). As the replacement liquid 70, a liquid that can be replaced with the rinse liquid 62 can be used. As the replacement liquid 70, it is possible to use a liquid having affinity with the rinsing liquid 62 (for example, pure water), that is, a liquid that can be mixed without being separated.

  Further, as the replacement liquid 70, a liquid that can be replaced with a solution 72 described later can be used. As the replacement liquid 70, a liquid having an affinity with the solution 72 described later, that is, a liquid that can be mixed without being separated can be used.

  It is desirable that the substitution liquid 70 and the solvent used in the solution 72 containing the sublimable substance 74 described later have an affinity for each other. The replacement liquid 70 and the solvent used for the solution 72 may use the same liquid or different liquids. It is desirable that the rinsing liquid 62 and the solvent used for the solution 72 have an affinity for each other. The same liquid may be used for the rinse liquid 62 and the solvent used for the solution 72, and different liquids may be used.

  As the replacement liquid 70, for example, aliphatic hydrocarbons, aromatic hydrocarbons, esters, ketones, alcohols and ethers, polyhydric alcohols, pyrrolidone solvents, and mixtures thereof can be used. . Examples of the substitution liquid 70 include water, methanol, ethanol, IPA (isopropyl alcohol), butanol, ethylene glycol, propylene glycol, NMP (N-methyl-2-pyrrolidone), DMF (N, N-dimethylformamide), DMA. (N, N-dimethylacetamide) and DMSO (dimethyl sulfoxide), hexane, toluene, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), propylene glycol monopropyl ether (PGPE), propylene glycol monoethyl ether (PGEE), gamma butyl lactone (GBL), acetylacetone, 3-pentanone, 2-heptanone, ethyl lactate, cyclohexanone, dibutyl ether, hydride Fluoroether (HFE), ethyl nonafluoroisobutyl ether, ethyl nonafluorobutyl ether, m- xylene hexafluoride, cyclohexane and the like can be used a solvent containing these mixtures.

For example, a method of placing the semiconductor substrate 50 on a spinner apparatus and supplying the replacement liquid 70 to the surface of the rotating semiconductor substrate 50 can be used for the treatment with the replacement liquid 70.
Note that the step of supplying the replacement liquid 70 (S21) can be omitted. In this case, the rinse liquid 62 is replaced with a solution 72 described later. It is desirable that the rinse liquid 62 and the solvent used for the solution 72 have affinity. The same liquid may be used for the rinse liquid 62 and the solvent used for the solution 72, and different liquids may be used.

  Next, as shown in FIGS. 3 and 4B, a solution 72 is supplied to the semiconductor substrate 50 (S22). As the solution 72, a liquid that can be satisfactorily replaced with the replacement liquid 70 can be used. As the solution 72, it is possible to use a liquid having a good affinity with the replacement liquid 70 (for example, IPA), that is, a liquid that can be mixed well without being separated.

  For the treatment with the solution 72, for example, a method of placing the semiconductor substrate 50 on a spinner device and supplying the solution 72 to the surface of the rotating semiconductor substrate 50 can be used. As a result, the replacement liquid 70 is replaced with the solution 72.

  It is desirable that the substitution liquid 70 and the solvent used for the solution 72 have affinity. The substitution liquid 70 and the solvent used for the solution 72 may use the same liquid or different liquids.

  Examples of the solvent used for the solution 72 include aliphatic hydrocarbons, aromatic hydrocarbons, esters, ketones, alcohols and ethers, polyhydric alcohols, pyrrolidone solvents, and mixtures thereof. be able to. Examples of the solvent used for the solution 72 include water, methanol, ethanol, IPA (isopropyl alcohol), butanol, propanol, ethylene glycol, propylene glycol, NMP (N-methyl-2-pyrrolidone), DMF (N, N- Dimethylformamide), DMA (N, N-dimethylacetamide) and DMSO (dimethylsulfoxide), hexane, toluene, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), propylene glycol monopropyl ether (PGPE), Propylene glycol monoethyl ether (PGEE), gamma butyl lactone (GBL), acetylacetone, 3-pentanone, 2-heptanone, ethyl lactate, cyclohexano , Dibutyl ether, hydrofluoroether (HFE), ethyl nonafluoroisobutyl ether, ethyl nonafluorobutyl ether, m-xylene hexafluoride, cyclohexane, formic acid, acetic acid, pyridine, diethylamine, dimethylamine, ethylenediamine, triethylamine, dimethylacetamide, diethyl Acetamide, formamide, and a solvent containing a mixed solution thereof can be used.

  As the solution 72, for example, IPA can be used as a solvent selected from the liquids described above. The solution 72 can be prepared by using a sublimable substance 74 as a solute, for example, by dissolving the sublimable substance 74 in a concentration range of 0.01 g / ml or more and 0.4 g / ml or less.

  The sublimable substance exemplified in the present embodiment means an organic substance having a vapor pressure of 5 Pa or less at room temperature, and a substance that sublimates from a solid to a gas by reducing pressure and / or heating (under reduced pressure and / or heating conditions). Means a substance having a sublimation property). The sublimable substance 74 can include, for example, substances represented by the following general formulas A1, A2, A3, A4, B1, B2, B3, B4, B5, C1, C2, D1, and D2. As the sublimation substance 74, for example, cyclohexane-1,2-dicarboxylic acid, trimellitic anhydride, or the like can be used.

（式Ａ１、Ａ２、Ａ３、Ａ４中、Ｘ^１、Ｘ^２及びＸ^１、Ｘ^２及びＸ^３は、それぞれ独立して、ヒドロキシ基（−ＯＨ）、カルボキシル基（−ＣＯＯＨ）、アミノ基（−ＮＨ_２）、アミド基（−ＣＯＮＨ_２）、ニトロ基（−ＮＯ_２）、メチルエステル基（−ＣＯＯ−ＣＨ_３）の何れかを示す。）

(In formulas A1, A2, A3 and A4, X ¹ , X ² and X ¹ , X ² and X ³ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (— NH ₂ ), an amide group (—CONH ₂ ), a nitro group (—NO ₂ ), or a methyl ester group (—COO—CH ₃ ).

（式Ｂ１、Ｂ２、Ｂ３、Ｂ４及びＢ５中、Ｘ^１、Ｘ^２、Ｘ^３及びＸ^４は、それぞれ独立して、ヒドロキシ基（−ＯＨ）、カルボキシル基（−ＣＯＯＨ）、アミノ基（−ＮＨ_２）、アミド基（−ＣＯＮＨ_２）、ニトロ基（−ＮＯ_２）、メチルエステル基（−ＣＯＯ−ＣＨ_３）、メトキシ基（−ＯＣＨ_３）、エトキシ基（−ＯＣＨ_２ＣＨ_３）、プロポキシ基（−ＯＣＨ_２ＣＨ_２ＣＨ_３）の何れかを示す。）

(In formulas B1, B2, B3, B4 and B5, X ¹ , X ² , X ³ and X ⁴ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH _2), amido (-CONH _2), a nitro group _(-NO 2), a methyl ester group _(-COO-CH 3), methoxy group (-OCH _3), an ethoxy group _(-OCH 2 _CH 3), propoxy (Indicates any one of —OCH ₂ CH ₂ CH ₃ )

（式Ｃ１及びＣ２中、Ｘ^１及びＸ^２は、それぞれ独立して、ヒドロキシ基（−ＯＨ）、カルボキシル基（−ＣＯＯＨ）、アミノ基（−ＮＨ_２）、アミド基（−ＣＯＮＨ_２）、ニトロ基（−ＮＯ_２）、メチルエステル基（−ＣＯＯ−ＣＨ_３）、メトキシ基（−ＯＣＨ_３）、エトキシ基（−ＯＣＨ_２ＣＨ_３）、プロポキシ基（−ＯＣＨ_２ＣＨ_２ＣＨ_３）の何れかを示す。）

(In the formulas C1 and C2, X ¹ and X ² are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH ₂ ), an amide group (—CONH ₂ ), nitro, group _(-NO 2), a methyl ester group _(-COO-CH 3), methoxy group (-OCH _3), an ethoxy group _(-OCH 2 _CH 3), or propoxy _(-OCH 2 _CH 2 _{CH 3)} Is shown.)

（式Ｄ１及びＤ２中、Ｘ^１、Ｘ^２、Ｘ^３及びＸ^４は、それぞれ独立して、ヒドロキシ基（−ＯＨ）、カルボキシル基（−ＣＯＯＨ）、アミノ基（−ＮＨ_２）、アミド基（−ＣＯＮＨ_２）、ニトロ基（−ＮＯ_２）、メチルエステル基（−ＣＯＯ−ＣＨ_３）、メトキシ基（−ＯＣＨ_３）、エトキシ基（−ＯＣＨ_２ＣＨ_３）、プロポキシ基（−ＯＣＨ_２ＣＨ_２ＣＨ_３）の何れかを示し、Ｒは、カルボニル基（−ＣＯ−）、ペプチド結合（−ＣＯＮＨ−）、エステル結合（−ＣＯＯ−）、エーテル結合（−Ｏ−）、（−ＮＨＮＨＯ−）結合、（−ＣＯＣＯＯ−）結合、（−ＣＨＣＨ−）結合の何れかを示す。）
昇華性物質７４は、また、下記表１、表２、表３、表４、表５、表６及び表７に示す物質を含むことができる。

(In formulas D1 and D2, X ¹ , X ² , X ³ and X ⁴ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH ₂ ), an amide group ( -CONH _2), a nitro group _(-NO 2), a methyl ester group _(-COO-CH 3), methoxy group (-OCH _3), an ethoxy group _(-OCH 2 _CH 3), propoxy (-OCH ₂ CH ₂ CH ₃ ) and R is a carbonyl group (—CO—), a peptide bond (—CONH—), an ester bond (—COO—), an ether bond (—O—), or a (—NNHHO—) bond. , (-COCOO-) bond or (-CHCH-) bond.
The sublimable substance 74 can also include the substances shown in Table 1, Table 2, Table 3, Table 4, Table 5, Table 6, and Table 7 below.

  The substances listed in Table 1 are substances corresponding to the formulas A1 to A4.

表２に掲げる物質は、式Ｂ１及びＢ２に対応する物質を示したものである。

The substances listed in Table 2 are substances corresponding to the formulas B1 and B2.

表３に掲げる物質は、式Ｂ３に対応する物質を示したものである。

The substances listed in Table 3 represent substances corresponding to Formula B3.

表４に掲げる物質は、式Ｂ４に対応する物質を示したものである。

The substances listed in Table 4 represent substances corresponding to formula B4.

表５に掲げる物質は、式Ｂ５に対応する物質を示したものである。

The substances listed in Table 5 are substances corresponding to the formula B5.

表６に掲げる物質は、式Ｃ１及びＣ２に対応する物質を示したものである。

The substances listed in Table 6 are substances corresponding to the formulas C1 and C2.

表７に掲げる物質は、式Ｄ１及びＤ２に対応する物質を示したものである。

The substances listed in Table 7 are substances corresponding to the formulas D1 and D2.

次に、図３及び図４（ｃ）に示すように、半導体基板５０に付着した溶液７２から溶媒を蒸発させて、昇華性物質７４を半導体基板５０上に析出させる（Ｓ２３）。昇華性物質７４が析出すると、固体の析出物７６となり、固化する。固化した析出物７６は、半導体基板５０上に形成された構造体５６の間を埋設するように形成され、隣接する構造体５６を固体として支持しているため、構造体５６の倒壊を抑制することができる。

Next, as shown in FIG. 3 and FIG. 4C, the solvent is evaporated from the solution 72 attached to the semiconductor substrate 50 to precipitate the sublimable substance 74 on the semiconductor substrate 50 (S23). When the sublimable substance 74 is deposited, it becomes a solid deposit 76 and solidifies. The solidified precipitate 76 is formed so as to be embedded between the structures 56 formed on the semiconductor substrate 50, and supports the adjacent structures 56 as solids, so that the collapse of the structures 56 is suppressed. be able to.

  Next, as shown in FIGS. 3 and 4D, the precipitate 76 (sublimable substance 74) is sublimated (S24). The precipitate 76 exhibits sublimation when set to a predetermined temperature and a predetermined pressure, and changes from a solid state (solid phase) to a gas state (gas phase) without passing through a liquid state (liquid phase). The precipitate 76 can be removed from the semiconductor substrate 50 by exhausting the precipitate 76 (sublimable substance 74) in a gaseous state. For example, as conditions for sublimating the sublimable substance 74, it is desirable to set the temperature to be lower than the melting point of the sublimable substance 74 and to set the pressure to 10 kPa or less.

  As described above, since the precipitate 76 can be removed by sublimating it, it does not go through a liquid state in the drying step. Therefore, in the process in which the precipitate 76 is removed, that is, in the drying process, the structure 56 is not pulled by the surface tension of the liquid. In addition, the deposit 76 is embedded between the structures 56 and supports the structure 56 as a solid. Even while the deposit 76 is removed by sublimation, the structure 56 is supported until it is completely removed. That is, the deposit 76 continues to support the structure 56 until it is removed. Therefore, the collapse of the structure 56 can be suppressed. When the removal by the sublimation of the precipitate 76 (sublimable substance 74) is completed, the drying process of this embodiment is completed (S14). After the above-described removal by sublimation, treatments such as plasma irradiation, ozone exposure, and excimer UV irradiation may be performed.

Through the above steps, the liquid adhering to the surface of the semiconductor substrate 50 that has undergone the liquid treatment is replaced with a solution containing a sublimable substance, and then a precipitate 76 (sublimable substance 74) is deposited, which is subsequently sublimated. Thereby, it becomes possible to perform the drying process, ie, the process of removing the deposit 76, without going through a liquid state. As a result, it is possible to dry the semiconductor substrate 50 that has undergone the liquid treatment while avoiding the collapse of the structure 56. That is, it is possible to provide a method for manufacturing a semiconductor device capable of suppressing pattern collapse of a semiconductor substrate on which a fine pattern is formed when the semiconductor substrate after liquid processing is dried.
(Selection of sublimable substances)
The inventors conducted the following examinations and experiments in selecting the sublimable substance 74.

  First, a substance that can be a candidate for the sublimable substance 74 was selected from the following viewpoints. That is, it is sublimable from the viewpoints of a melting point of 15 to 200 ° C., a boiling point of 80 to 300 ° C., a molecular weight of 10 to 300, no halogen element, and no poisonous or deleterious substances. Substances that can be candidates for the substance 74 were selected.

  As described above, the sublimable substance exemplified in the present embodiment means an organic substance having a vapor pressure of 5 Pa or less at room temperature, and means a substance that sublimates from a solid to a gas by reducing pressure and / or heating. To do.

  Next, a solution was prepared by dissolving the substance selected from the above viewpoint in IPA. This solution was applied onto a semiconductor substrate on which a line-and-space structure was formed, and the film forming property was evaluated. Next, a sublimable substance was deposited and removed by sublimation, and the pattern collapse rate of the structure was evaluated.

  As a result of this experiment, good results were obtained for the substances listed in Tables 1 to 7 above. That is, for the substances listed in Tables 1 to 7, the film formability was good, and the pattern collapseability was improved (the pattern collapse rate was reduced).

In addition, from the results of the above experiments, the inventors obtained the following knowledge.
That is, in the case of the cyclohexane ring basic skeleton described in Table 1, a substance having a carboxyl group (—COOH) bonded to the 1,2-position, 1,3-position, or 1,4-position (cyclohexane-1,2-dicarboxylic acid, In cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid), good film formability and improvement in pattern collapse were observed. That is, in the substance in which two carboxyl groups are bonded to the cyclohexane ring, good film formability and improvement in pattern collapse were observed. In addition, in the substance (cyclohexane-1,2,4-tricarboxylic acid) in which a carboxyl group is bonded to the 1,2,4 position of the cyclohexane ring described in Table 1, good film formability and improvement of pattern collapse property are recognized. It was. That is, in the case of a substance having a cyclohexane ring as a basic skeleton, good film formability and pattern in a substance having a carboxyl group at 1, 2, 1, 3, 1, 4, or 1, 2, 4 position. Improvement in collapsibility was observed.

With respect to the benzene disubstituted substances listed in Table 2, good film formability and pattern in a substance (phthalic acid, aminoacetophenone) in which a carboxyl group or an amino group (—NH ₂ ) is bonded to the ortho position or the meta position. Improvement in collapsibility was observed.

For the benzene trisubstituted substances listed in Table 3, substances having a carboxyl group, hydroxy group (—OH), or methoxy group (—O—CH ₃ ) bonded to the 1, 2, 4 positions (vanillin, 4-hydroxy) In phthalic acid, trimellitic acid, dimethoxyacetophenone), good film formability and improvement in pattern collapse were observed. Also, among the benzene tri-substituted substances, the substances in which carboxyl groups are bonded to the 1, 2, 4 positions (trimellitic acid) and the anhydrides (trimellitic anhydride) in which the carboxyl groups in the 1, 2 positions are dehydrated are also used. Good film formability and improved pattern collapse were confirmed.

  For the benzene tri-substituted substances listed in Table 4, good film formability and improved pattern collapsibility in the substance (5-hydroxyisophthalic acid) in which carboxyl groups or hydroxy groups are bonded at the 1, 3, and 5 positions. Was recognized.

With respect to the benzene tetra-substituted substances listed in Table 5, good film-forming properties can be obtained for substances having carboxyl groups, hydroxy groups, or methyl ester groups (—COO—CH ₃ ) bonded to the 1, 3, 4, and 5 positions. Improved pattern collapse was observed. In particular, in a substance (gallic acid, methyl gallate) having a hydroxy group bonded to the 3, 4, 5 position and a carboxyl group or methyl ester group bonded to the 1-position, good film formability and pattern collapsibility Improvement was observed.

  As for the disubstituted substances of naphthalene listed in Table 6, good film formability and improvement of pattern collapse were observed in the substance having two hydroxy groups bonded thereto. In particular, in a substance (1,7-dihydronaphthalene) having a hydroxy group bonded to the 1,7-position, good film formability and improvement in pattern collapse were observed.

  Regarding the benzophenone disubstituted substances listed in Table 7, good film formability and improved pattern collapse were observed in the substance having a hydroxy group bonded to the 4,4′-position (4,4′-dihydroxybenzophenone). It was. As for the benzophenone tetra-substituted substance, a substance having a hydroxy group bonded to the 2,2 ′, 4,4′-position (2,2 ′, 4,4′-tetrahydroxybenzophenone) has good film-forming properties, Improvement of pattern collapse was observed.

From the knowledge based on the above experimental results, the inventors have arrived at the idea that polar substituents are effective as substituents. For example, a silicon-based film has a natural oxide film formed on the surface, and there are OH groups on the surface of the natural oxide film. It is considered that a material having a functional group (substituent) capable of interacting with an OH group can be satisfactorily formed into a film. Therefore, as a substituent, a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH ₂ ), an amide group (—CONH ₂ ), a nitro group (—NO ₂ ), a methyl ester group (—COO) It came to the idea that it is desirable to use a substance having any one of —CH ₃ ), methoxy group (—OCH ₃ ), ethoxy group (—OCH ₂ CH ₃ ), and propoxy group (—OCH ₂ CH ₂ CH ₃ ). . Further, the present inventors have arrived at the idea that it is more preferable to use a hydroxy group or a carboxyl group as a substituent.

  Further, in benzophenone, a site where two benzene rings are bonded includes a carbonyl group (—CO—), an amide group (—CONH—), an ester bond (—COO—), a (—NHNHO—) bond, an ether bond ( The idea has been reached that it is desirable to use a substance having any one of —O—), —COCOO— bond and —CHCH— bond.

From the above knowledge and idea, the general formulas A1 to A4, B1 to B5, C1, C2, D1, and D2 described above were derived.
(Other embodiments)
The embodiment described above may be applied to a manufacturing method of a NAND type or NOR type flash memory, EPROM, DRAM, SRAM, other semiconductor memory devices, various logic devices, or other semiconductor devices.

  Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  In the drawings, 50 is a semiconductor substrate, 52 is a film to be etched, 54 is an etching mask, 56 is a structure, 58 is a foreign body, 60 is a cleaning solution, 62 is a rinsing solution, 70 is a replacement solution, 72 is a solution, and 74 is a sublimation. , A precipitate (precipitate) 76.

Claims (6)

Applying a liquid treatment to the surface of the semiconductor substrate on which a fine pattern is formed, and attaching a first liquid to the surface of the semiconductor substrate;
Replacing the first liquid adhering to the surface of the semiconductor substrate with a solution in which the deposited substance is dissolved in the second liquid;
Evaporating the second liquid to deposit the deposit on the surface of the semiconductor substrate;
A step of changing the deposited substance from a solid to a gas by reducing pressure and / or heating, and removing it.
The deposited substance is

(In formulas A1, A2, A3 and A4, X ¹ , X ² and X ³ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH ₂ ), an amide group, (Indicates any one of (—CONH ₂ ), nitro group (—NO ₂ ), and methyl ester group (—COO—CH ₃ ).)

(In formulas B1, B2, B3, B4 and B5, X ¹ , X ² , X ³ and X ⁴ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH _2), amido (-CONH _2), a nitro group _(-NO 2), a methyl ester group _(-COO-CH 3), methoxy group (-OCH _3), an ethoxy group _(-OCH 2 _CH 3), propoxy (Indicates any one of —OCH ₂ CH ₂ CH ₃ )
Including at least one substance selected from the substances indicated by
In the substances represented by the formulas A1, A4, B1, B3, and B5, one of the groups bonded to the adjacent positions is a carboxyl group, and the other includes any of a carboxyl group, a hydroxy group, and an amino group. A method of manufacturing a semiconductor device. Applying a liquid treatment to the surface of the semiconductor substrate on which a fine pattern is formed, and attaching a first liquid to the surface of the semiconductor substrate;
Replacing the first liquid adhering to the surface of the semiconductor substrate with a third liquid;
Replacing the third liquid with a solution in which the deposited substance is dissolved in the second liquid;
Evaporating the second liquid to deposit the deposit on the surface of the semiconductor substrate;
A step of changing the deposited substance from a solid to a gas by reducing pressure and / or heating, and removing it.
The first liquid and the third liquid have affinity;
The second liquid and the third liquid have affinity;
The deposited substance is

(In formulas A1, A2, A3 and A4, X ¹ , X ² and X ³ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH ₂ ), an amide group, (Indicates any one of (—CONH ₂ ), nitro group (—NO ₂ ), and methyl ester group (—COO—CH ₃ ).)

(In formulas B1, B2, B3, B4 and B5, X ¹ , X ² , X ³ and X ⁴ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH _2), amido (-CONH _2), a nitro group _(-NO 2), a methyl ester group _(-COO-CH 3), methoxy group (-OCH _3), an ethoxy group _(-OCH 2 _CH 3), propoxy (Indicates any one of —OCH ₂ CH ₂ CH ₃ )
Including at least one substance selected from the substances indicated by
In the substances represented by the formulas A1, A4, B1, B3, and B5, one of the groups bonded to the adjacent positions is a carboxyl group, and the other includes any of a carboxyl group, a hydroxy group, and an amino group. A method of manufacturing a semiconductor device.   3. The method of manufacturing a semiconductor device according to claim 1, wherein the deposited substance is a substance in which at least two or more carboxyl groups are bonded to cyclohexane.   3. The method of manufacturing a semiconductor device according to claim 1, wherein the deposited substance has a structure in which two carboxyl groups are bonded adjacent to benzene.   The second liquid contains at least one substance selected from aliphatic hydrocarbons, aromatic hydrocarbons, esters, ketones, alcohols and ethers, polyhydric alcohols, and pyrrolidone solvents. A method for manufacturing a semiconductor device according to any one of claims 1 to 4. A chemical used in a drying process in the manufacturing process of a semiconductor device,
A precipitate is dissolved in a liquid containing at least one substance selected from aliphatic hydrocarbons, aromatic hydrocarbons, esters, ketones, alcohols and ethers, polyhydric alcohols, and pyrrolidone solvents. The deposited material is

(In formulas A1, A2, A3 and A4, X ¹ , X ² and X ³ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH ₂ ), an amide group, (Indicates any one of (—CONH ₂ ), nitro group (—NO ₂ ), and methyl ester group (—COO—CH ₃ ).)

(In formulas B1, B2, B3, B4 and B5, X ¹ , X ² , X ³ and X ⁴ are each independently a hydroxy group (—OH), a carboxyl group (—COOH), an amino group (—NH _2), amido (-CONH _2), a nitro group _(-NO 2), a methyl ester group _(-COO-CH 3), methoxy group (-OCH _3), an ethoxy group _(-OCH 2 _CH 3), propoxy (Indicates any one of —OCH ₂ CH ₂ CH ₃ )
Including at least one substance selected from the substances indicated by
In the substances represented by the formulas A1, A4, B1, B3, and B5, one of the groups bonded to adjacent positions is a carboxyl group, and the other is a chemical solution containing any of a carboxyl group, a hydroxy group, and an amino group.

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