METHOD FOR PREPARING IODOSILANES

Abstract

Provided is methodology for the preparation of highly-desired iodosilanes such as H.sub.2SiI.sub.2 and HSi.sub.3, via a reaction of alkylaminosilanes with certain substituted acid iodides. In one embodiment, bis(diethylamino)silane is reacted with benzoyl iodide to provide diiodosilane.

Claims

1. A method for preparing a compound having the formula (I):
(H).sub.xSi(I).sub.y  (I); wherein x is 1 or 2, y is 2 or 3, and the sum of x plus y is 4, the method comprising: contacting a compound of the formula (A):
(H).sub.xSi(N(R.sup.1)(R.sup.2)).sub.y  (A); wherein (i) each R.sup.1 and each R.sup.2 is independently chosen from a C.sub.1-C.sub.6 alkyl group, a C.sub.3-C.sub.8 cycloaliphatic group, or hydrogen, or (ii) R.sup.1 and R.sup.2 are taken together with the nitrogen atom to which they are bonded to form a C.sub.4-C.sub.7 nitrogen-containing saturated or aromatic ring, provided that no more than one of R.sup.1 and R.sup.2 is hydrogen; with a compound of the formula: ##STR00005## wherein R.sup.3 is chosen from C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6 substituted alkyl, benzyl, substituted benzyl, biphenyl, naphthyl, phenyl, or substituted phenyl, to produce a compound of formula (I).

2. The method of claim 1, wherein the compound of formula (I) is H.sub.2SiI.sub.2.

3. The method of claim 1, wherein the compound of formula (I) is HSiI.sub.3.

4. The method of claim 1, wherein R.sup.1 and R.sup.2 are chosen from methyl, ethyl, propyl, sec-butyl, and t-butyl.

5. The method of claim 1, wherein at least one of R.sup.1 and R.sup.2 is t-butyl.

6. The method of claim 1, wherein at least one of R.sup.1 and R.sup.2 is cyclohexyl.

7. The method of claim 1, wherein R.sup.1 and R.sup.2 are taken together with the nitrogen atom to which they are attached, to form a pyrrole, pyrrolidine, or piperidine ring.

8. The method of claim 1, wherein R.sup.3 is C.sub.1-C.sub.6 alkyl.

9. The method of claim 1, wherein R.sup.3 is phenyl.

10. The method of claim 1, wherein R.sup.3 is substituted phenyl.

11. The method of claim 10, wherein R.sup.3 is 4-fluorophenyl.

12. The method of claim 10, wherein R.sup.3 is 3,5-difluorophenyl.

13. The method of claim 1, wherein at least one of R.sup.1 and R.sup.2 is ethyl and R.sup.3 is methyl or phenyl.

14. A method for preparing a compound having the formula (II):
(H).sub.z(I).sub.ySi—Si(I).sub.y(H).sub.z  (II) wherein y is 2 or 3, z is 0 or 1, and the sum of y and z is 3, the method comprising: contacting a compound of the formula (B):
H.sub.z((R.sup.1)(R.sup.2)N).sub.ySi—Si(N(R.sup.2)(R.sup.1)).sub.yH.sub.z  (B); wherein (i) each R.sup.1 and each R.sup.2 is independently chosen from a C.sub.1-C.sub.6 alkyl group, a C.sub.3-C.sub.8 cycloaliphatic group, or hydrogen, or (ii) R.sup.1 and R.sup.2 are taken together with the nitrogen atom to which they are bonded to form a C.sub.4-C.sub.7 nitrogen-containing saturated or aromatic ring, provided that no more than one of R.sup.1 and R.sup.2 is hydrogen; with a compound of the formula: ##STR00006## wherein R.sup.3 is chosen from C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6 substituted alkyl, benzyl, substituted benzyl, biphenyl, naphthyl, phenyl, or substituted phenyl, to produce a compound of formula (II).

15. The method of claim 14, wherein R.sup.1 and R.sup.2 are chosen from methyl, ethyl, propyl, sec-butyl, and t-butyl.

16. The method of claim 14, wherein at least one of R.sup.1 or R.sup.2 is t-butyl.

17. The method of claim 14, wherein at least one of R.sup.1 or R.sup.2 is cyclohexyl.

18. The method of claim 14, wherein R.sup.1 and R.sup.2 are taken together with the nitrogen atom to which they are attached, to form a pyrrole, pyrrolidine, or piperidine ring.

19. The method of claim 14, wherein R.sup.3 is C.sub.1-C.sub.6 alkyl.

20. The method of claim 14, wherein R.sup.3 is phenyl.

21. The method of claim 14, wherein at least one of R.sup.1 and R.sup.2 is ethyl and R.sup.3 is methyl or phenyl.

Description

DETAILED DESCRIPTION

[0007] As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

[0008] The term “about” generally refers to a range of numbers that is considered equivalent to the recited value (e.g., having the same function or result). In many instances, the term “about” may include numbers that are rounded to the nearest significant figure.

[0009] Numerical ranges expressed using endpoints include all numbers subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4 and 5).

[0010] In a first aspect, the disclosure provides a method for preparing a compound having the formula (I):

(H).sub.xSi(I).sub.y  (I); [0011] wherein x is 1 or 2, y is 2 or 3, and the sum of x plus y is 4, the method comprising: [0012] contacting a compound of the formula (A):

(H).sub.xSi(N(R.sup.1)(R.sup.2)).sub.y  (A); [0013] wherein (i) each R.sup.1 and each R.sup.2 is independently chosen from a C.sub.1-C.sub.6 alkyl group, a C.sub.3-C.sub.8 cycloaliphatic group, or hydrogen, or (ii) R.sup.1 and R.sup.2 are taken together with the nitrogen atom to which they are bonded to form a C.sub.4-C.sub.7 nitrogen-containing saturated or aromatic ring, provided that no more than one of R.sup.1 and R.sup.2 is hydrogen; [0014] with a compound of the formula:

##STR00001## [0015] wherein R.sup.3 is chosen from C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6 substituted alkyl, benzyl, substituted benzyl, biphenyl, naphthyl, phenyl, or substituted phenyl, to produce a compound of formula (I).

[0016] In a second aspect, the disclosure provides a method for preparing a compound having the formula (II):

(H).sub.z(I).sub.ySi—Si(I).sub.y(H).sub.z  (II) [0017] wherein y is 2 or 3, z is 0 or 1, and the sum of y and z is 3, the method comprising: contacting a compound of the formula (B):

H.sub.z((R.sup.1)(R.sup.2)N).sub.ySi—Si(N(R.sup.2(R.sup.1)).sub.yH.sub.z  (B); [0018] wherein (i) each R.sup.1 and each R.sup.2 is independently chosen from a C.sub.1-C.sub.6 alkyl group, a C.sub.3-C.sub.8 cycloaliphatic group, or hydrogen, or (ii) R.sup.1 and R.sup.2 are taken together with the nitrogen atom to which they are bonded to form a C.sub.4-C.sub.7 nitrogen-containing saturated or aromatic ring, provided that no more than one of R.sup.1 and R.sup.2 is hydrogen; [0019] with a compound of the formula:

##STR00002## [0020] wherein R.sup.3 is chosen from C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6 substituted alkyl, benzyl, substituted benzyl, biphenyl, naphthyl, phenyl, or substituted phenyl, to produce a compound of formula (II).

[0021] In the above process, it will be appreciated that the product of formula (I) is produced when the reactant of formula (A) is utilized and the product of formula (II) is produced when the reactant of formula (B) is utilized. In one embodiment, the compound of formula (I) is H.sub.2SiI.sub.2. In another embodiment, the compound of formula (I) is HSiI.sub.3.

[0022] In one embodiment, the compound of the formula

(H).sub.xSi(N(R.sup.1)(R.sup.2)).sub.y  (A),

is chosen from compounds such as
H.sub.2Si(N(CH.sub.3).sub.2).sub.2;
H.sub.2Si(N(CH.sub.2CH.sub.3).sub.2).sub.2;
H.sub.2Si(N(CH.sub.2CH.sub.3)(CH.sub.3)).sub.2
H.sub.2Si(N(CH.sub.2CH.sub.2CH.sub.3).sub.2).sub.2;
H.sub.2Si(N(CH.sub.2CH.sub.2CH.sub.2CH.sub.3).sub.2).sub.2;
H.sub.2Si(N(t-butyl).sub.2).sub.2;
H.sub.2Si(N(H)(t-butyl)).sub.2;
HSi(N(CH.sub.3).sub.2).sub.3;
HSi(N(CH.sub.2CH.sub.3).sub.2).sub.3;
HSi(N(CH.sub.2CH.sub.2CH.sub.3).sub.2).sub.3;
HSi(N(CH.sub.2CH.sub.2CH.sub.2CH.sub.3).sub.2).sub.3;
HSi(N(t-butyl).sub.2).sub.3; and the like.

[0023] As used herein, the term “substituted phenyl” denotes a phenyl group substituted one to five times with a group chosen from C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6 alkylamino, di-(C.sub.1-C.sub.6 alkyl)amino, and halo. In one embodiment, halo is fluoro.

[0024] As used herein, the term “substituted C.sub.1-C.sub.6 alkyl” denotes a C.sub.1-C.sub.6 alkyl group substituted one to five times with a group chosen from C.sub.1-C.sub.6 alkylamino, di-(C.sub.1-C.sub.6 alkyl)amino, and halo.

[0025] As used herein, the term “substituted benzyl” denotes a benzyl group having one to five substituents on the aromatic ring chosen from C.sub.1-C.sub.6 alkylamino, di-(C.sub.1-C.sub.6 alkyl)amino, and halo.

[0026] The methodology of the invention can be practiced neat or in the presence of an aprotic solvent which is non-reactive with the starting materials or iodosilane products. Such solvents include aliphatic, aromatic, and halogenated hydrocarbon solvents which are devoid of moieties and functional groups such as oxygen, esters, carboxy groups, and ketones. Examples include benzene, toluene, hexane, cyclohexane, pentane, dichloromethane, 1,2-dichloroethane, tetralin, decalin, mesitylene, dibromoethane, tetrachloroethylene, or chlorobenzene, and the like.

[0027] The reaction generally proceeds at room temperature and atmospheric pressure.

[0028] The method for preparing the precursor compounds of the invention can be conducted in standard batch or continuous mode reactors. One of ordinary skill in the art would recognize the scale and type of reactors which could be utilized in the context of the reagents and products so produced.

[0029] Compounds of the formulae (I) and (H) are useful as precursors in the formation of silicon-containing films on the surface of a microelectronic device by methods such as atomic layer deposition (see for example, U.S. Pat. Nos. 10,580,645 and 10,424,477, incorporated herein by reference). Also, by way of example, compounds of formulae (I) and (II) can be introduced into a deposition chamber for the purposes of thermal CVD or ALD, or for the purposes of performing plasma-enhanced ALD or CVD. In these cases, a co-reactant gas can be introduced to deposit an SiO.sub.2 film, via oxidation in an oxidizing environment with O.sub.2, O.sub.3, N.sub.2O, or mixtures thereof. Similarly, compounds of formulae (I) and (II) can be introduced into a deposition chamber for the purposes of thermal CVD or ALD, or for the purposes of performing plasma-enhanced ALD or CVD. In these cases, a co-reactant gas can be introduced to deposit a silicon nitride film, via nitridation with N.sub.2, NH.sub.3, hydrazine or alkylhydrazine containing mixtures. The deposited films serve as dielectric layers within the microelectronic device.

EXAMPLES

Example 1: Diiodosilane

[0030] A 25.0 g (143 mMol) sample of bis(diethylamino)silane was combined with 4 equivalents, 133.0 g (574 mMol) of benzoyl iodide and 500 mL of hexanes. The reaction was allowed to proceed for 2 hours, after which time, the desired diiodosilane product was detected by .sup.1H NMR and all starting material was consumed. In the case of addition of benzoyl iodide to bis(diethylamino)silane, the observed yield was 7% (determined from concentration in hexanes). In the case of addition of bis(diethylamino)silane to benzoyl iodide, the observed yield was 3.5% (determined from concentration in hexanes). NMR samples were spiked to confirm with diiodosilane to confirm the identity of the signal.

[0031] .sup.1H NMR (400 MHz, C.sub.6D.sub.6): δ 3.61 (.sup.1J.sub.Si—H=141.5 Hz, H—SiI.sub.2, 2H).

Example 2: Diiodosilane

[0032] A 20.0 g (115 mMol) sample of bis(diethylamino)silane was combined with 4 equivalents, 78.0 g (459 mMol) of acetyl iodide and 400 mL of hexanes. The reaction was allowed to proceed for 10 minutes, after which time, trace amounts of the desired diiodosilane product was detected by .sup.1H NMR and all starting material was consumed. Upon attempted isolation, decomposition of the product occurred. In the case of addition of acetyl iodide to bis(diethylamino)silane, the observed isolated yield was 0%.

[0033] .sup.1H NMR (400 MHz, C.sub.6D.sub.6): δ 3.61 (.sup.1J.sub.Si-H=141.5 Hz, H—SiI.sub.2, 2H).

Example 3: Diiodosilane

[0034] A 0.68 g (3.9 mMol) sample of bis(diethylamino)silane was combined with 4 equivalents, 4.69 g (15.6 mMol) of 2-fluorobenzoyl iodide and 10 mL of hexanes. The reaction was allowed to proceed for 10 minutes, after which time, 43% conversion of the desired diiodosilane product was detected by .sup.1H NMR and all starting material was consumed. After an additional, 20 hr of stirring, the case of addition of 2-fluorobenzoyl iodide to bis(diethylamino)silane, the observed yield was 20%.

[0035] .sup.1H NMR (400 MHz, C.sub.6D.sub.6): δ 3.61 (.sup.1J.sub.Si-H=141.5 Hz, H—SiI.sub.2, 2H).

Example 4: Diiodosilane

[0036] A 0.27 g (1.6 mMol) sample of bis(diethylamino)silane was combined with 4 equivalents, 2.3 g (6.2 mMol) of 3,5-difluorobenzoyl iodide and 5 mL of hexanes. The reaction was allowed to proceed for 10 minutes, after which time, 81% conversion of the desired diiodosilane product was detected by .sup.1H NMR and all starting material was consumed. After an additional, 20 hr of stirring, the case of addition of 3,5-difluorobenzoyl iodide to bis(diethylamino)silane, the observed yield was 20%.

[0037] .sup.1H NMR (400 MHz, C.sub.6D.sub.6): δ 3.61 (.sup.1J.sub.Si-H=141.5 Hz, H—SiI.sub.2, 2H).

Example 5 Diiodosilane

[0038] A 3.3 g (18.9 mMol) sample of bis(diethylamino)silane was combined with 4 equivalents, 1.0 g (4.7 mMol) of 2,2-dimethylpropanoyl iodide and 3 mL of hexanes. The reaction was allowed to proceed for 10 minutes, after which time, 20% of the desired diiodosilane product was detected by 1H NMR with 72% of the starting material remaining. After an additional, 20 hr of stirring, the case of addition of 2,2-dimethylpropanoyl iodide to bis(diethylamino)silane, the observed yield was 0.1%.

[0039] .sup.1H NMR (400 MHz, C.sub.6D.sub.6): δ 3.61 (.sup.1J.sub.Si-H=141.5 Hz, H—SiI.sub.2, 2H).

ASPECTS

[0040] In a first aspect, the disclosure provides a method for preparing a compound having the formula (I):

(H).sub.xSi(I).sub.y  (I); [0041] wherein x is 1 or 2, y is 2 or 3, and the sum of x plus y is 4, the method comprising: [0042] contacting a compound of the formula (A):

(H).sub.xSi(N(R.sup.1)(R.sup.2)).sub.y  (A); [0043] wherein (i) each R.sup.1 and each R.sup.2 is independently chosen from a C.sub.1-C.sub.6 alkyl group, a C.sub.3-C.sub.8 cycloaliphatic group, or hydrogen, or (ii) R.sup.1 and R.sup.2 are taken together with the nitrogen atom to which they are bonded to form a C.sub.4-C.sub.7 nitrogen-containing saturated or aromatic ring, provided that no more than one of R.sup.1 and R.sup.2 is hydrogen; [0044] with a compound of the formula:

##STR00003## [0045] wherein R.sup.3 is chosen from C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6 substituted alkyl, benzyl, substituted benzyl, biphenyl, naphthyl, phenyl, or substituted phenyl, to produce a compound of formula (I).

[0046] In a second aspect, the disclosure provides the method of the first aspect, wherein the compound of formula (I) is H.sub.2SiI.sub.2.

[0047] In a third aspect, the disclosure provides the method of the first aspect, wherein the compound of formula (I) is HSiI.sub.3.

[0048] In a fourth aspect, the disclosure provides the method of the first or second aspect, wherein R.sup.1 and R.sup.2 are chosen from methyl, ethyl, propyl, sec-butyl, and t-butyl.

[0049] In a fifth aspect, the disclosure provides the method of any one of the first through fourth aspects, wherein at least one of R.sup.1 and R.sup.2 is t-butyl.

[0050] In a sixth aspect, the disclosure provides the method of the first, second, or third aspects, wherein at least one of R.sup.1 and R.sup.2 is cyclohexyl.

[0051] In a seventh aspect, the disclosure provides the method of the first, second, or third aspects, wherein R.sup.1 and R.sup.2 are taken together with the nitrogen atom to which they are attached, to form a pyrrole, pyrrolidine, or piperidine ring.

[0052] In an eighth aspect, the disclosure provides the method of any one of the first through the seventh aspects, wherein R.sup.3 is C.sub.1-C.sub.5 alkyl.

[0053] In a ninth aspect, the disclosure provides the method of any one of the first through seventh aspects, wherein R.sup.3 is phenyl.

[0054] In a tenth aspect, the disclosure provides the method of any one of the first through seventh aspects, wherein R.sup.3 is substituted phenyl.

[0055] In an eleventh aspect, the disclosure provides the method of any one of the first through seventh, or tenth aspects, wherein R.sup.3 is 4-fluorophenyl.

[0056] In a twelfth aspect, the disclosure provides the method of any one of the first through seventh or tenth aspects, wherein R.sup.3 is 3,5-difluorophenyl.

[0057] In a thirteenth aspect, the disclosure provides the method of the first, second, or third aspects, wherein at least one of R.sup.1 and R.sup.2 is ethyl and R.sup.3 is methyl or phenyl.

[0058] In a fourteenth aspect, the disclosure provides a method for preparing a compound having the formula (II):

(H).sub.z(I).sub.ySi—Si(I).sub.y(H).sub.z  (II) [0059] wherein y is 2 or 3, z is 0 or 1, and the sum of y and z is 3, the method comprising: [0060] contacting a compound of the formula (B):

H.sub.2((R.sup.1)(R.sup.2)N).sub.ySi—Si(N(R.sup.2)(R.sup.1)).sub.yH.sub.z  (B), [0061] wherein (i) each R.sup.1 and each R.sup.2 is independently chosen from a C.sub.1-C.sub.6 alkyl group, a C.sub.3-C.sub.8 cycloaliphatic group, or hydrogen, or (ii) R.sup.1 and R.sup.2 are taken together with the nitrogen atom to which they are bonded to form a C.sub.4-C.sub.7 nitrogen-containing saturated or aromatic ring, provided that no more than one of R.sup.1 and R.sup.2 is hydrogen: [0062] with a compound of the formula:

##STR00004## [0063] wherein R.sup.3 is chosen from C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6 substituted alkyl, benzyl, substituted benzyl, biphenyl, naphthyl, phenyl, or substituted phenyl, to produce a compound of formula (II).

[0064] In a fifteenth aspect, the disclosure provides the method of the fourteenth aspect, wherein R.sup.1 and R.sup.2 are chosen from methyl, ethyl, propyl, sec-butyl, and t-butyl.

[0065] In a sixteenth aspect, the disclosure provides the method of the fourteenth aspect, wherein at least one of R.sup.1 or R.sup.2 is t-butyl.

[0066] In a seventeenth aspect, the disclosure provides the method of the fourteenth aspect, wherein at least one of R.sup.1 or R.sup.2 is cyclohexyl.

[0067] In an eighteenth aspect, the disclosure provides the method of the fourteenth aspect, wherein R.sup.1 and R.sup.2 are taken together with the nitrogen atom to which they are attached, to form a pyrrole, pyrrolidine, or piperidine ring.

[0068] In a nineteenth aspect, the disclosure provides the method of any one of the fourteenth through eighteenth aspects, wherein R.sup.3 is C.sub.1-C.sub.6 alkyl.

[0069] In a twentieth aspect, the disclosure provides the method of any one of the fourteenth through eighteenth aspects, wherein R.sup.3 is phenyl.

[0070] In a twenty-first aspect, the disclosure provides the method of the fourteenth aspect, wherein at least one of R.sup.1 and R.sup.2 is ethyl and R.sup.3 is methyl or phenyl.

[0071] Having thus described several illustrative embodiments of the present disclosure, those of skill in the art will readily appreciate that yet other embodiments may be made and used within the scope of the attached claims. Numerous advantages of the disclosure covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details without exceeding the scope of the disclosure. The disclosure's scope is, of course, defined in the language in which the appended claims are expressed.