Patent ID: 8414971

Claim:
A method for depositing a solid ZnO film onto a substrate from a reagent solution comprising the steps of: providing a supply of reagent solution containing a source of Zn, a source of O, and at least three ligands comprising sodium citrate, ammonium hydroxide, and potassium nitrilotriacetate, and maintained at a first temperature at which homogeneous reactions are substantially inhibited within said reagent solution; dispensing a controlled flow of said reagent solution from a showerhead assembly; positioning said substrate to receive at least a portion of said controlled flow of said reagent over a selected area of said substrate; providing a raised structure peripheral to said selected area whereby a controlled volume of said reagent solution may be maintained upon said substrate and replenished at a selected rate; and, heating said substrate and said controlled volume of said reagent solution upon said substrate to a second temperature, higher than said first temperature, whereby deposition of zinc oxide from said reagent solution may be initiated.