Silane compositions, methods of making the same, method for forming a semiconducting and/or silicon-containing film, and thin film structures formed therefrom
View Patent ↗A method of making hydrogenated Group IVA compounds having reduced metal-based impurities, compositions and inks including such Group IVA compounds, and methods for forming a semiconductor thin film. Thin semiconducting films prepared according to the present invention generally exhibit improved conductivity, film morphology and/or carrier mobility relative to an otherwise identical structure made by an identical process, but without the washing step. In addition, the properties of the present thin film are generally more predictable than those of films produced from similarly prepared (cyclo)silanes that have not been washed according to the present invention. The present invention advantageously provides semiconducting thin film structures having qualities suitable for use in electronics applications, such as display devices or RF ID tags, while enabling high-throughput manufacturing processes that form such thin films in seconds or minutes, rather than hours or days as with conventional photolithographic processes.
1. A composition, comprising:
a) a cyclic Group IVA compound of the formula (AH z ) n , where n is from 3 to 12, each A is independently Si or Ge, and each of the n instances of z is independently 1 or 2; and
b) less than 100 parts of aluminum per million atoms of A in said Group IVA compound.
2. The composition of claim 1 , comprising less than 1 ppm with respect to atoms of A in said Group IVA compound.
3. The composition of claim 1 , wherein A is Si.
4. The composition of claim 1 , wherein z is 2.
5. The composition of claim 1 , wherein n is from 5 to 8.
6. The composition of claim 1 , wherein at least 85 mol % of said composition consists essentially of said cyclic Group IVA compound.
7. An ink for making a semiconductor film, comprising:
a) the composition of claim 1 ; and
b) a solvent in which said composition is soluble.
8. The ink of claim 7 , wherein said cyclic Group IVA compound is present in said ink in a percentage by volume of from 0.1% to 50%.
9. The ink of claim 7 , wherein said solvent is aprotic.
10. The ink of claim 7 , wherein said solvent has a boiling point of less than 250° C. at atmospheric pressure.
11. The ink of claim 7 , consisting essentially of said composition and said solvent.
12. The ink of claim 7 , wherein each A in the formula (1) is Si.
13. The ink of claim 7 , wherein n is from 5 to 8.
14. A thin film structure comprising a cured, at least partially hydrogenated, at least partially amorphous Group IVA element, said Group IVA element consisting essentially of at least one of silicon and germanium, said thin film having less than 100 ppm of Group IIIA metal contaminants (other than intentionally added boron) relative to said Group IVA element.
15. The thin film structure of claim 14 , having less than 10 ppm of Group IIIA metal contaminants (other than intentionally added boron) relative to said Group IVA element.
16. The thin film structure of claim 14 , having less than 1 ppm of Group IIIA metal contaminants (other than intentionally added boron) relative to said Group IVA element.
17. The thin film structure of claim 14 , wherein said Group IVA element further consists essentially of a dopant covalently bound to Group IVA atoms therein.
18. The thin film structure of claim 17 , having a dopant concentration profile or gradient that is substantially uniform throughout a thickness of said thin film.