PROCESS FOR THE GENERATION OF THIN INORGANIC FILMS

Abstract

The present invention is in the field of processes for the generation of thin inorganic films on substrates. In particular the present invention relates to a process comprising bringing a com-pound of general formula (I) into the gaseous or aerosol state L.sub.n-M-X.sub.mL=formula and depositing the compound of general formula (I) from the gaseous or aerosol state onto a solid substrate, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, are independent of each other hydrogen, an alkyl group, an aryl group, or a SiA.sub.3 group with A being an alkyl or aryl group, and at least two of R.sup.1, R.sup.2, R.sup.3, R.sup.4 are a SiA.sub.3 group, n is an integer from 1 to 4, M is a metal or semimetal, X is a ligand which coordinates M, and m is an integer from 0 to 4.

##STR00001##

Claims

1. A process comprising bringing a compound of general formula (I) into the gaseous or aerosol state ##STR00007## and depositing the compound of general formula (I) from the gaseous or aerosol state onto a solid substrate, wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independent of each other hydrogen, an alkyl group, an aryl group, or a SiA.sub.3 group with A being an alkyl or aryl group, and at least two of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are a SiA.sub.3 group, n is an integer from 1 to 4, M is a metal or semimetal, X is a ligand which coordinates M, and m is an integer from 0 to 4.

2. The process according to claim 1, wherein the compound of general formula (I) is chemisorbed on the surface of the solid substrate.

3. The process according to claim 1, wherein the deposited compound of general formula (I) is decomposed by removal of all ligands L and X.

4. The process according to claim 3, wherein the decomposition is effected by exposure to water, an oxygen plasma, an oxygen radical, ozone, nitrous oxide, nitric oxide, or nitrogen dioxide.

5. The process according to claim 3, wherein the decomposition is effected by hydrogen, hydrogen radicals, hydrogen plasma, ammonia, ammonia radicals, ammonia plasma, silane, hydrazine, N,N-dimethylhydrazine, disilane, trisilane, cyclopentasilane, cyclohexasilane, dimethyl silane, diethyl silane, phenyl silane, or trisilylamine.

6. The process according to claim 3, wherein a sequence of depositing the compound of general formula (I) onto a solid substrate and decomposing the deposited compound of general formula (1) is performed at least twice.

7. The process according to claim 1 wherein M is Sr, Ba, Ni or Co.

8. A compound of general formula (I) ##STR00008## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independent of each other hydrogen, an alkyl group, an aryl group, or a SiA.sub.3 group with A being alkyl or aryl group, and at least two of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are a SiA.sub.3 group, n is an integer from 1 to 4, M is metal or semimetal, X is a ligand which coordinates M, and m is an integer from 0 to 4.

9. The compound according to claim 8, wherein R.sup.1 and R.sup.4 are a SiA.sub.3 group with A being alkyl or aryl group and R.sup.2 and R.sup.3 are hydrogen.

10. The compound according to claim 8, wherein n is 2.

11. The compound according to claim 8, wherein M is Ba, Sr, Ni or Co.

12. A compound of general formula (II) ##STR00009## wherein A is an alkyl or an aryl group, R.sup.2 and R.sup.3 are independent of each other hydrogen, an alkyl group, an aryl group, or a SiA.sub.3 group with A being alkyl or aryl group.

13. A process for forming a film formation process on a solid substrate, comprising applying the compound of claim 8 to the solid substrate.

Description

EXAMPLES

[0065] All synthetic steps involving the synthesis or handling of metal complexes were conducted under inert conditions using oven-dried glassware, dry solvents and an inert argon or nitrogen atmosphere.

Example 1

Synthesis of the 2,5-bis(trimethylsilyl)-pyrrole

[0066] ##STR00004##

[0067] A solution of 2,2,6,6-tetramethylpiperidine (TMP) (161 g, 1.14 mol) in THF (500 mL) was cooled to 72 C. and n-butyllithium (451 ml, 1.13 mmol, 2.5 M in hexane) was added. The resulting suspension was allowed to stir for 30 minutes at 72 C. N-Boc-pyrrole (72.4 g, 0.433 mol) was added. The resulting solution was allowed to stir for 90 min at 72 C. and trimethylsilyl chloride (122 g, 1.13 mol) was added and allowed to stir for further 10 minutes at 72 C. The mixture was allowed to warm to room temperature and stirred overnight. The crude mixture was treated with 300 ml dist. water. Layers were separated and the combined organic layers were dried over Na.sub.2SO.sub.4, filtered off the drying agent and concentrated in vacuum to yield 159.5 g of the crude product which was subjected to the next transformation without further purification.

[0068] Deprotected pyrrole was obtained after pyrolysis of the carbamate at 20 mbar, 82-97 C.: 107 g of a colorless liquid was obtained which crystallized upon cooling to below room temperature.

[0069] .sup.1H-NMR (400 MHz, THF-d.sub.8): 9.77 (s, 1H), 6.32 (d, J=2.0 Hz, 2H), 0.22 (s, 18H).

Example 2

[0070] ##STR00005##

[0071] 5 g (23.6 mmol) of ligand L-1 were dissolved in 30 ml of THF. 1 g (25.0 mmol) KH in 100 ml THF were added via a cannula and stirred at ambient temperature for 5 h. 4.62 g (11.8 mmol) Bal.sub.2 in 150 ml THF were added via a cannula and stirred over night at ambient temperature. The resulting suspension was filtrated. The solvent of the filtrate was evaporated in vacuo. The slightly yellow oily residue was washed with n-hexane yielding 4.49 g crude product. 2.2 g of the crude product were purified by sublimation at 0.001 mbar and 180 C. yielding in 1.1 g of pure complex C-2.

[0072] .sup.1H-NMR (THF-d.sub.8, 360 MHz, 25 C.): (in ppm) 6.7 s (2H), 0.2 s (18H). Elemental analysis: found: C: 42.1, N: 4.9, H: 7.1, Ba: 23.4, Si: 18.8, calc.: C: 43.0, N: 5.0, H: 7.2, Ba: 24.6, Si: 20.1.

Scheme for examples 3 and 4

[0073] ##STR00006##

Example 3

[0074] 3 g (10.15 mmol) of ligand L-2 were dissolved in 50 ml of THF. 0.41 g (10.15 mmol) KH in 50 ml THF were added via a cannula and stirred at ambient temperature for 48 h. 1.73 g (5.07 mmol) Bal.sub.2 in 80 ml THF were added via a cannula and stirred for 72 h at ambient temperature. The resulting suspension was filtrated. The solvent of the filtrate evaporated in vacuo.

[0075] .sup.1H-NMR (THF-d.sub.8, 500 MHz, 25 C.): (in ppm) 6.89 s (2H), 0.81 s (18H), 0.35 s (6H).

Example 4

[0076] 3 g (10.15 mmol) of ligand L-2 were dissolved in 50 ml of THF. 0.41 g (10.15 mmol) KH in 50 ml THF were added via a cannula and stirred at ambient temperature for 48 h. 1.98 g (5.07 mmol) Bal.sub.2 in 80 ml THF were added via a cannula and stirred for 72 h at ambient temperature. The resulting suspension was filtered. The solvent of the filtrate evaporated in vacuo. The brown residue was washed with 20 ml of n-hexane yielding 1,6 g of complex C-4.

[0077] .sup.1H-NMR (THF-d.sub.8, 500 MHz, 25 C.): (in ppm) 6.84 s (2H), 0.85 s (18H), 0.33 s (6H).