Apparatus for forming metal oxide film, method for forming metal oxide film, and metal oxide film
A film forming apparatus includes a first solution container, a second solution container, a reaction chamber, a first path, and a second path. The first solution container stores a source solution containing metal. The second solution container stores hydrogen peroxide. A substrate is in the reaction chamber, and the reaction chamber includes a heating unit that heats the substrate. The first path supplies a source solution from the first solution container to the reaction chamber. The second path supplies hydrogen peroxide from the second solution container to the reaction chamber.
1. A method for forming a metal oxide film, the method comprising:
forming a source solution comprising metal into a mist;
heating a substrate;
supplying the source solution formed into a mist onto a first main surface of the substrate through a first supply path;
supplying ozone onto the first main surface of the substrate; and
supplying hydrogen peroxide through a second path different from the first supply path onto the first main surface of the substrate,
wherein the method further comprises, in the following order:
preliminarily preparing data showing a relationship among a molar ratio of an amount of the hydrogen peroxide to an amount of the zinc in the source solution, a carrier concentration of the metal oxide film, and a mobility of the metal oxide film;
determining an amount of the hydrogen peroxide supplied with the data, and
supplying the determined amount of the hydrogen peroxide through the second path onto the first main surface of the substrate,
wherein
the substrate is arranged under atmospheric pressure,
the source solution is converted into a mist by an ultrasonic atomizer,
the metal is zinc, and
wherein the heating is performed at a temperature of 190 to 240° C.
2. The method of claim 1 , wherein the source solution further comprises ammonia.
3. The method of claim 1 , wherein the source solution further comprises ethylenediamine.
4. The method of claim 1 , wherein the molar ratio of the amount of the hydrogen peroxide to the amount of the zinc in the source solution is 20 or smaller.
5. The method of claim 1 , wherein supplying the hydrogen peroxide further comprises supplying a dopant of a predetermined conductivity type onto the first main surface of the substrate with the hydrogen peroxide through the second path.
6. The method of claim 1 , wherein the source solution comprises boron, nitrogen, fluorine, aluminum, phosphorus, gallium, arsenic, niobium, indium, antimony, bismuth, vanadium, tantalum, or any combination thereof.
7. The method of claim 1 , wherein the source solution comprises water, an alcohol, or a mixed solution thereof.