High purity alkyl tin compounds and manufacturing methods thereof

Patent metadata

Field	Value
Publication number	US-12545692-B2
Application number	US-202318205009-A
Country	US
Kind code	B2
Filing date	Jun 2, 2023
Priority date	Jun 2, 2022
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

Monoalkyl tin triamide compounds having purity of at least about 99 mol % and the chemical formula RSn(NMe 2 ) 3 are described. R 1 is selected from R A , R B , and R C ; R A is a primary alkyl group having about 1 to 10 carbon atoms, R B is a secondary alkyl group having about 3 to 10 carbon atoms, and R C is a tertiary alkyl group having about 3 to 10 carbon atoms; each R 2 is independently an alkyl group having about 1 to 10 carbon atoms; and a content of R 1 Sn(NR 2 2 ) 2 (N(R 2 )CH 2 NR 2 2 ) is less than about 1 mol %. Methods for synthesizing, purifying, and storing these compounds are also provided. The monoalkyl tin compounds may be used for the formation of high-resolution EUV lithography patterning precursors and are attractive due to their high purity and minimal concentration of dialkyl tin and other tin impurities.

First claim

We claim:

1 . A composition comprising a monoalkyl tin triamide compound having formula (3) and having a purity of at least 99 mol %

wherein a content of a compound having formula (5) is less than 0.2 mol % with respect to the compound of formula (3):

2 . The composition according to claim 1 , wherein a content of dialkyl bis(dialkylamino) tin having formula (2) is less than 1 mol %:
R 1 2 Sn(NR 2 2 ) 2   (2)
wherein R 1 is isopropyl and R 2 is methyl.

3 . The composition according to claim 1 , wherein a total content of tetrakis(dialkylamino)tin is less than 1 mol %.

4 . The composition according to claim 1 , wherein a content of tetraalkyl tin is less than 1 mol %.

5 . The composition according to claim 1 , wherein an APHA is less than 20.

6 . The composition according to claim 1 , wherein the content of the compound having formula (5) is less than 0.05 mol %.

7 . A method of synthesizing the composition according to claim 1 , the method comprising:
(a) lithiating a solution comprising a dimethylamine and a first solvent to produce a lithium dimethylamide solution having a concentration of up to 10 wt %; (b) adding a solution comprising an isopropyl trichlorotin and a second solvent; wherein the amount of lithium dimethylamide in the solution is at least 3.09 equivalents relative to the amount of isopropyl trichlorotin; (c) removing LiCl salt product by filtration; and (d) removing the first solvent and the second solvent under vacuum to produce a crude product containing the monoalkyl tin triamide having formula (3), wherein steps (a) to (d) are performed substantially without light exposure.

8 . The method according to claim 7 , wherein the content of the compound having the formula (5) is less than 0.05 mol %.

9 . The method according to claim 7 , wherein step (b) is performed at −78° C. to 40° C.

10 . The method according to claim 9 , wherein step (b) is performed at 0° C. to 10° C.

11 . The method according to claim 7 , wherein the first solvent and the second solvent are each independently selected from the group consisting of a hydrocarbon solvent, an aromatic solvent, and an ether solvent.

12 . The method according to claim 7 , wherein steps (a) and (b) are performed in a stainless steel vessel.

13 . The method according to claim 7 , further comprising distilling the crude product containing the monoalkyl tin triamide having formula (3) substantially without light exposure to yield the composition according to claim 1 .

14 . The method according to claim 13 , wherein the distillation comprises distilling the crude product containing the monoalkyl tin triamide having formula (3) at a pressure of 0.1 to 50 torr, discarding any distillate before the boiling point of the monoalkyl tin triamide having formula (3), and collecting a distillate obtained at the boiling point of the monoalkyl tin triamide having formula (3).

15 . The method according to claim 13 , wherein the distillation comprises fractionally distilling the crude product containing the monoalkyl tin triamide having formula (3) using an operating pressure of 0.1 to 50 torr and a pot temperature of 50° C. to 120° C., to yield the composition according to claim 1 , wherein a content of dialkyl bis(dialkylamino) tin having formula (2) is less than 0.1 mol %:
R 1 2 Sn(NR 2 2 ) 2   (2)

wherein R 1 is isopropyl and R 2 is methyl.

16 . The method according to claim 13 , comprising performing the distillation using a condenser temperature within 1° C. to 10° C. of the dew point of the monoalkyl tin triamide compound having formula (3) at the operating pressure and at a reflux ratio of about 10 to about 100.

Assignees

• Gelest Inc
• Mitsubishi Chem Corp

Inventors

• Yang Li
• Hioki Yuta

Classifications

• C07F7/2296

  Purification, stabilisation, isolation · CPC title

• C07F7/2284 Primary

  Compounds with one or more Sn-N linkages · CPC title