Method for preparing an organotin compound

Abstract

A facile method is provided for preparing certain organotin compounds having alkyl and alkylamino, or alkyl and alkoxy, substituents, which provide high purity forms of the organotin compounds that are particularly useful as precursors in the deposition of high purity tin oxide films, for example in extreme ultraviolet (EUV) lithography techniques used in the manufacture of certain microelectronic devices.

Description

Technical Field

[0001] The present invention belongs to the field of organotin chemistry. In particular, the present invention relates to an easy method for preparing certain organotin compounds.

Background Art

[0002] It has been shown that certain organotin compounds are beneficial for the deposition of high-purity tin oxide films in applications such as extreme ultraviolet (EUV) lithography technology used in the manufacture of certain microelectronic devices.

[0003] Organotin compounds having a combination of alkylamino groups and alkyl groups have attracted particular interest. Accordingly, there is a need for an improved method for producing such organotin compounds in high-purity form for use in the deposition of high-purity tin oxide films.

Summary of the Invention

[0004] Provided is an easy method for preparing certain organotin compounds having alkyl substituents and alkylamino substituents, or alkyl substituents and alkoxy substituents. In one embodiment, the method provides an organotin precursor compound in high-purity form, such as tris(dimethylamide)isopropyltin (CAS No. 1913978-89-8). Accordingly, the product of the method is particularly beneficial in the deposition of high-purity tin oxide films, for example, in extreme ultraviolet (EUV) lithography technology used in the manufacture of microelectronic devices.

[0005] The present invention relates to a compound of formula (I) TIFF0007684409000001.tif34170[wherein each R is independently selected from C 1 ~C 5 alkyl groups, each R 1 is independently selected from C 1 ~C 5 alkyl groups, R 2 is hydrogen or C 1 ~C 5Selected from alkyl groups relates to a method for preparing. The above method involves a compound of formula (A) TIFF0007684409000002.tif34170[wherein M is selected from sodium, lithium, or potassium] contacting with a compound of formula L-R 2 [wherein L is a leaving group].

[0006] The present invention further relates to a compound of formula (I) TIFF0007684409000003.tif34170[wherein each R is independently C 1 ~C 5 selected from alkyl groups, and each R 1 is independently C 1 ~C 5 selected from alkyl groups, R 2 is hydrogen or C 1 ~C 5 selected from alkyl groups] relates to a method for preparing. The above method involves a compound of formula (II) TIFF0007684409000004.tif24170[wherein each R 3 is independently selected from straight-chain or branched-chain C 1 ~C 8 alkyl groups, phenyl groups, and substituted phenyl groups] contacting with a compound of formula (R 4 ) 3 Si-N(R)(R 1 ).

[0007] The present invention further relates to a compound of formula (II) TIFF0007684409000005.tif24170[wherein each R 3 is independently selected from straight-chain or branched-chain C 1 ~C 8 alkyl groups, phenyl groups, and substituted phenyl groups, and R 2 is hydrogen or C 1 ~C 5 selected from alkyl groups] relates to.

DETAILED DESCRIPTION OF THE INVENTION

[0008] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in the sense of "and / or" unless the context clearly dictates otherwise.

[0009] The term "about" generally refers to a range of numerical values that are considered equivalent to the stated value (e.g., having the same function or result). In many cases, the term "about" may include numbers rounded to the nearest significant digit.

[0010] Numerical ranges expressed using endpoints include all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0011] In a first aspect, the present invention provides a method for preparing a compound of formula (I) TIFF0007684409000006.tif34170[wherein each R is independently selected from C 1 ~C 5 alkyl groups, each R 1 is independently selected from C 1 ~C 5 alkyl groups, R 2 is hydrogen or selected from C 1 ~C 5 alkyl groups] The above method involves combining a compound of formula (A) TIFF0007684409000007.tif34170 with a compound of formula L-R 2 wherein L is a leaving group such as a halide, or a substituted or unsubstituted aromatic or alkyl sulfonate, and M is selected from sodium, lithium, or potassium. For example, the compound of formula (A) is a compound of formula L-R 2can be contacted with a compound [wherein L is bromo, iodo, or chloro]. As a specific example, L is iodo.

[0012] In the above method, each R and each R 1 can be independently selected from linear or branched alkyl groups including methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, sec-butyl, n-pentyl, isopentyl, or sec-pentyl groups. In one particular embodiment, each R and each R 1 are independently selected from C 1 ~C 3 alkyl groups, such as methyl, ethyl, or propyl groups. Further, in the above method, R 2 is selected from C 1 ~C 5 alkyl groups, which can be substituted or unsubstituted linear or branched alkyl groups. For example, R 2 can be a linear or branched alkyl group including methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, sec-butyl, n-pentyl, isopentyl, or sec-pentyl groups. Further, R 2 can be a cyclic C 1 ~C 5 group, such as a cyclopropyl group. Also, R 2 can be an unsaturated C 1 ~C 5 group, such as a vinyl group or an ethynyl group. Any of these R 2 can be further substituted, for example, with one or more halogen groups or ether groups. For example, R 2 is a fluorinated alkyl group having the formula -(CH 2 ) n (CH a F b ) m where m is 1 to 5 and m + n is 1 to 5, b is 1 to 3 and a + b = 3, and monofluoro-substituted C 1 ~C 5 alkyl groups, such as -CH 2F group or -CH 2 CH 2 F group, and perfluorinated C 1 ~C 5 group, for example -CF 3 group or CF 2 CF 3 group. Alternatively, R 2 may be an alkyl ether group, where the alkyl part is C 1 ~C 5 alkyl group. In one particular embodiment, each R and each R 1 is methyl, and R 2 is methyl, ethyl, or isopropyl. Also, M may preferably be lithium. The compound of formula (A) is a useful intermediate in the synthesis of the compound of formula (I).

[0013] Compound of formula A TIFF0007684409000008.tif34170 can be prepared by the reaction of a dihalostannane, such as SnCl 2 with a compound of formula (B) TIFF0007684409000009.tif24170.

[0014] In this regard, SnCl 2Based on the amount of , at least about 3 molar equivalents of the compound of formula (B) are used, and the compound of formula (A) is formed, and additional equivalents may be used if necessary. For example, from at least about 3.1 molar equivalents, including at least about 3.25, 3.5, or 3.75, up to about 4 equivalents of the compound of formula (B) may be used. Examples of the compound of formula (B) include non-nucleophilic strong bases such as lithium diethylamide, lithium methylethylamide, lithium diisopropylamide, etc. The reaction can usually be carried out at a temperature ranging from about -15°C to a moderately elevated temperature, such as about 60°C, but other temperatures may be used depending on, for example, the reaction scale or reaction time. For example, the reaction temperature can be between about -30°C and about 90°C, including about -10°C to about 80°C, and about -5°C to about 70°C. In some embodiments, it is preferred that the reaction temperature exceeds 0°C. Suitable solvents include aprotic solvents such as alkanes, such as hexane, and aromatic solvents, such as toluene, as well as polar aprotic solvents such as, for example, dimethoxyethane and tetrahydrofuran. Other suitable solvents are known or can be determined by those skilled in the art. Further, one or more of the steps of this method can preferably be carried out under conditions that minimize exposure of the materials and / or products to light (e.g., use of amber glassware).

[0015] Accordingly, once the compound of formula (A) is formed, it can react with the compound of formula L-R 2 (where R 2 and L are as described above) to obtain the compound of formula (I). In one embodiment, the compound of formula (I) has a specific structure TIFF0007684409000010.tif37170.

[0016] In a second aspect, the present invention provides a method for preparing a compound of formula (I) TIFF0007684409000011.tif34170[where each R and R 1 are as described above] In this aspect, the above method involves a compound of formula (II) TIFF0007684409000012.tif24170[wherein each R 3 is independently selected from a linear or branched C 1 ~C 8 alkyl group, a phenyl group, and a substituted phenyl group] is combined with a compound of formula (R 4 ) 3 Si-N(R)(R 1 ) [wherein R 4 is a C 1 ~C 3 alkyl group]. For example, the compound of formula (II) can be contacted with a compound of formula (R 4 ) 3 Si-N(R)(R 1 ) [wherein R 4 is a methyl group]. In one embodiment, for the compound of formula (II), R 2 is methyl, ethyl, or isopropyl, and each R 3 is methyl.

[0017] In this embodiment, to form the compound of formula (I), at least about 3 molar equivalents of the compound of formula (R 4 ) 3 Si-N(R)(R 1 ) are used compared to the compound of formula (II), although additional equivalents may be used if necessary. In one specific example, the compound of formula (R 4 ) 3 Si-N(R)(R 1 ) is (CH 3 ) 3 SiN(CH 3 ) 2 .

[0018] Examples of substituted phenyl groups are C 1 ~C 4 alkyl, C 1 ~C 4 alkoxy, C 1 ~C 4 alkylsulfonyl, hydroxy, cyano, nitro, halo, trihalomethyl, phenyl, phenoxy, C 3 ~C 6It contains a phenyl group which is substituted one or more times with a group selected from cycloalkyl and the like. Specific examples of the substituted phenyl group include 2,6-di-t-butylphen-1-yl, 2,4,6-trimethylphenyl, and the like.

[0019] In a further aspect, the present invention relates to a compound of formula (II) as described above, which has surprisingly been found to be useful as an intermediate in the synthesis of compounds of formula (I).

[0020] The intermediate of formula (II) is a dihalostannane, for example SnCl 2 with a molar excess of a compound of the formula M-OR 3 [wherein M and R 3 are as described above] to give a compound of formula (C) TIFF0007684409000013.tif24170 [wherein n is 1 or more] which can be prepared by obtaining. Then, this compound is reacted with a compound of the formula X-R 2 to obtain a compound of formula (II).

[0021] In the above aspect, n is 1 or more depending on the relative size of the R 3 group of formula (C), and in certain cases, it may be a very large number or an indefinite number depending on the polymerization level of the repeating unit shown above. Thus, as shown, the compound of formula (C) tends to form even dimers, trimers, oligomers, and very long linear polymers of indefinite length. For example, the compound of formula (C) has the structure TIFF0007684409000014.tif43170. Furthermore, the formation of the compound of formula (C) always results in a mixed group of species such as dimers, trimers, etc. The intermediate compound of formula (C) can be prepared by reacting SnCl 2 with a compound of the formula M-OR 3 [wherein M and R 3 are as described above]. A molar excess, for example about 2 molar equivalents of the formula M-OR 3The compound of can be used in some cases, and additional equivalents may be used if necessary. For example, from at least about 2.1 molar equivalents, including at least about 2.25, 2.5, or 2.75, up to about 3 equivalents of the compound of formula (B) may be used. For the first embodiment, the reaction can be carried out at a temperature ranging from about -15 °C to a moderately elevated temperature, for example, about 60 °C, although other temperatures may be used. For example, the reaction temperature can be between about -30 °C and about 90 °C, including about -10 °C to about 80 °C, and about -5 °C to about 70 °C. In some embodiments, it is preferred that the reaction temperature exceeds 0 °C. Suitable solvents include, for example, aprotic solvents, including alkanes such as hexane and aromatic solvents such as toluene, as well as polar aprotic solvents, including, for example, dimethoxyethane and tetrahydrofuran. Other suitable solvents are known or can be determined by those skilled in the art. Further, one or more of the steps of this method can preferably be carried out under conditions that minimize exposure of the materials and / or products to light (e.g., use of amber glassware).

[0022] In another aspect, the present invention provides a method by which a compound of formula (I) as shown in the following scheme can be converted to a compound of formula (II) by treatment with an alcohol of formula R 3 -OH, for example, at room temperature. By converting the tin amide of formula (I) to the tin alkoxide of formula (II), any impurities generated by the reaction to form the tin amide are also converted. For example, the compound of formula (I) may contain an impurity having the formula (Ia) TIFF0007684409000016.tif40170 which may be particularly difficult to separate from the compound of formula (I) by distillation. These impurities may be much easier to remove from the compound of formula (II) when the mixture is converted to the corresponding alkoxide as shown above. Further, R 3When bulky, for example in the case of an isopropyl group, purification by recrystallization may also be possible. Once purified, the compound of formula (II) then reacts with a compound of formula (R 4 ) 3 Si-N(R)(R 1 ) as described above, thereby reforming the compound of formula (I) while reducing a significant amount of the compound of formula (Ia), for example removing this impurity in excess of 90%, 95%, 97% or 99%. Thus, this embodiment can be a method for purifying the compound of formula (I).

[0023] As shown above, the compound of formula (I) thus produced is useful as a precursor in the deposition of a tin oxide film on the surface of a microelectronic device,

[0024] The present invention can be further illustrated by the following examples of certain embodiments thereof, which are included for illustrative purposes only and are not intended to limit the scope of the invention unless otherwise clearly indicated.

Examples

[0025] Example 1 Tin(II) chloride (SnCl 2 )(1.0 g, 5.21 mmol) and lithium dimethylamide (LiN(CH 3 ) 2 )(0.836 g, 16.4 mmol) were placed in a 20 mL scintillation vial equipped with a magnetic stir bar and diluted with tetrahydrofuran (THF) (10 mL). The resulting pink mixture was heated at 55 °C for 60 hours. The resulting grey mixture was filtered through a 0.2 μm syringe filter to obtain a dark red solution. 2-Iodopropane (0.885 g, 5.21 mmol) was added to the resulting dark red solution and the reaction was heated at 60 °C with stirring for 1 hour, thereby changing the color to a lighter orange. The 1 1H-NMR and 119 119Sn-NMR of the resulting crude reaction mixture showed iPrSn(N(CH 3 ) 2) 3 Consistent with the formation of (119Sn-NMR, -64.18 ppm).

[0026] Example 2 (R 2 Sn(NR)(NR 1 ) from R 2 Sn(OR 3 ) 3 (Preparation of) iPrSn(N(CH 3 ) 2)3 was placed in a vial (1.0 g, 3.4 mmol), and hexane (3.5 mL) was added. Methanol (0.40 g, 12.5 mmol) was added to the mixture at room temperature, and the immediate occurrence of the reaction was confirmed by effervescence. After 5 minutes, the solvent was removed under reduced pressure to obtain a white solid (0.76 g, 2.98 mmol, 87.7% yield). 1 1H-NMR (400 MHz, C 6 D 6 , 298K) δ 3.81 (s, 9H); 2.38 (m, 1H); 1.48 (d, 6H) ppm.

[0027] Example 3 (R 2 Sn(OR 3 ) 3 from R 2 Sn(NR)(R 1 )(Preparation of) iPrSn(OCH 3 ) 3 (2.5 g, 9.8 mmol) was placed in a 40 ml vial equipped with a stir bar and diluted with 10 mL of toluene. In another vial, (CH 3 ) 3 SiN(CH 3 ) 2 (3.44 g, 29.4 mmol) was dissolved in 10 mL of toluene. The (CH 3 ) 3 SiN(CH 3 ) 2 solution was added to the iPrSn(OCH 3 ) 3 vial, and the resulting white mixture was heated at 70 °C with stirring for 12 hours. After 1 hour, the reaction mixture became a clear solution.

[0028] The next morning, the reactants became a slightly turbid colorless solution. The reactants were cooled to room temperature, and the volatiles were removed under reduced pressure to obtain a slightly turbid colorless liquid (mass: 2.44 g, crude yield: 84.7%).

[0029] The recovered material was placed in a 50 mL round-bottom flask equipped with a stir bar. A short-path distillation head was attached to a thermometer and a 10 mL recovery flask. The apparatus was placed under dynamic vacuum to establish a baseline of 800 Torr, and the vessel was heated to 60 °C. When the vessel temperature reached 58 °C, a colorless liquid was observed in the recovery flask (head temperature: 38 °C) at a pressure of 800 Torr. When no liquid was observed in the condenser, the heating mantle was turned off. 0.96 g was recovered, 31.4% yield. Samples of the product as-is were collected 1 H-NMR and 119 Sn-NMR confirmed the synthesis of iPrSn(N(CH 3 ) 2 ) 3 and was consistent with previously collected NMR data.

[0030] Example 4 In a reaction vessel, SnCl 2 was able to react with 2 molar equivalents of Li - OCH 3 . Subsequently, the resulting compound [Sn(OCH 3 ) 2 n was isolated and reacted with 2-iodopropane to obtain tris(methoxy)isopropylstannane. Subsequently, the resulting tris(methoxy)isopropylstannane was reacted with 3 molar equivalents of (CH 3 ) 3 Si - N(CH 3 ) 2 to obtain isopropyl(tris)dimethylaminostannane.

[0031] Example 5 - Synthesis of MeSn(NMe 2 ) 3 LiSn(NMe 2 ) 3 ​​(2.0 g, 7.75 mmol) was placed in a 40 mL vial equipped with a magnetic stir bar and dissolved in tetrahydrofuran (10 mL). In a separate vial, iodomethane (1.31 g, 9.29 mmol) was diluted with THF (2 mL), and the solution was added to the LiSn(NMe2)3 solution while stirring, whereby the reactants became turbid and warm to the touch. The resulting mixture was stirred at room temperature for 2 days. For the filtered aliquot of the reaction mixture 1 1H-NMR and 119 Sn-NMR were recorded. 1 1H-NMR (400 MHz, THF, 298K): δ 0.29 (s, 3H); 2.61 (s, 18H) ppm. 119 Sn {1H}-NMR (149 MHz, THF, 298K): δ -15.04 ppm.

[0032] Synthesis of Example 6 - EtSn(NMe 2 ) 3 LiSn(NMe (2.0 g, 7.75 mmol) was placed in a 40 mL vial equipped with a magnetic stir bar and dissolved in tetrahydrofuran (15 mL). In a separate vial, iodoethane (1.44 g, 9.29 mmol) was diluted with THF (2 mL), and the solution was cooled to -35 °C. Once cooled, the iodoethane solution was added to the LiSn(NMe 2 ) 3 solution while stirring, whereby the reactants became warm to the touch. The resulting mixture was stirred at room temperature for 20 minutes. For the filtered aliquot of the reaction mixture 2 ) 3 1H-NMR and 1 Sn-NMR were recorded. According to NMR, EtSn(NMe 119 ) 2 ) 3 was present. 1 1H-NMR (400 MHz, THF, 298K): δ 0.89 (t, 3H); 1.16 (q, 2H); 2.66 (s, 18H) ppm. 119Sn {1H}-NMR (149 MHz, THF, 298K): δ -39.13 ppm.

[0033] Example 7-CF 3 CH 2 Sn(OtBu) 3 Synthesis CF 3 CH 2 Sn(NMe 2 ) 3 (2 g, 5.98 mmol) was placed in a 40 mL amber vial equipped with a magnetic stir bar and diluted with hexane (3 mL). In a separate vial, tBuOH (1.32 g, 17.9 mmol) was dissolved in hexane (5 mL) and slowly added dropwise to the Sn-amide solution over 2 minutes with stirring. Slight effervescence was observed throughout the addition. Once the addition was complete, the resulting solution was stirred at room temperature for 10 minutes and then dried under reduced pressure to give a pale yellowish-brown solution. C 6 D 6 Recorded for the solution 1 H-NMR, 13 C-NMR, 19 F-NMR, and 119 Sn-NMR confirmed the formation of CF 3 CH 2 Sn(OtBu) 3 . Product purity by NMR > 90%. 1 H-NMR (400 MHz, C 6 D 6 , 298K): δ 1.31 (s, 27H); 1.76 (q, 2H) ppm. 13 C-NMR (100 MHz, C 6 D 6, 298K): 28.49 (q), 33.55, 33.69, 74.41 ppm. 119 Sn {1H}-NMR (149 MHz, C 6 D 6 , 298K): δ -228.35 (q) ppm. 19 F-NMR (376 MHz, C 6 D 6, 298K); δ -51.95 (t) ppm.

[0034] Although the invention has been described in detail with particular reference to certain of its embodiments, it is to be understood that variations and modifications can occur within the spirit and scope of the invention.

Claims

1. A method for preparing a compound of formula (I) [wherein each R is independently selected from C １ -C ５ alkyl groups, and each R １ is independently selected from C １ -C ５ alkyl groups, and R ２ is selected from vinyl or ethynyl groups] wherein the method comprises a compound of formula (A)

2. with a compound of formula L-R ２ which comprises contacting with a compound of formula L-R, where L is a leaving group and M is selected from sodium, lithium or potassium. The method according to claim 1, wherein L is a halide, or a substituted or unsubstituted aromatic sulfonate or alkyl sulfonate.

3. The method according to claim 1, wherein L is bromo, iodo, or chloro.

4. The method according to claim 1, wherein the compound of formula (A) is prepared by reacting a dihalostannane with a compound of formula (B)

5. and a compound of formula (B).

Images