Germanium films by polymer-assisted deposition
Highly ordered Ge films are prepared directly on single crystal Si substrates by applying an aqueous coating solution having Ge-bound polymer onto the substrate and then heating in a hydrogen-containing atmosphere. A coating solution was prepared by mixing water, a germanium compound, ethylenediaminetetraacetic acid, and polyethyleneimine to form a first aqueous solution and then subjecting the first aqueous solution to ultrafiltration.
1. A coating solution useful for preparing highly ordered Ge films, said coating solution prepared by combining water, a germanium compound, ethylenediaminetetraacetic acid, and a polyethyleneimine to form a first solution and thereafter subjecting the first solution to ultrafiltration, thereby forming the aqueous coating solution.
2. The coating solution of claim 1 , wherein the germanium compound is germanium oxide, germanium nitrate, germanium fluoride, germanium chloride, germanium bromide, or mixtures thereof.
3. The coating solution of claim 1 , wherein the polyethyleneimine is selected from polyethyleneimine and carboxylated polyethyleneimine.