Method for forming a thin film of a non-stoichiometric metal oxide
AssigneeMotorola, Inc.
InventorEric P. Menu
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Abstract
A method for forming a thin film (220) of luminescent zinc oxide includes the steps of: (i) providing a mixture (170) of powdered zinc oxide and powdered graphite, (ii) providing a substrate (140) at a distance of about 9 millimeters from the mixture (170), (iii) disposing the mixture (170) and substrate (140) within an apparatus (100) that provides a confined environment having a partial pressure of oxygen of about 0.21 atmospheres, (iv) heating the mixture (170) to a temperature of about 850 degrees Celsius, and (v) establishing a temperature gradient between the substrate (140) and the mixture (170) of about 15 degrees, the temperature of the substrate (140) being less than the temperature of the mixture (170).
Claims22
A method for forming a thin film of a non-stoichiometric metal oxide including the steps of:
- providing a mixture including powdered graphite and a powdered metal oxide, the powdered graphite 20-80% by volume of the mixture;
- providing a substrate made from a material capable of withstanding high temperatures and having a surface, disposing said mixture and the surface of said substrate within a confined environment, the surface of the substrate being spaced from said mixture by a distance;
- heating the mixture to a first temperature within 400-1000 degrees Celsius;
- providing within the confined environment a partial pressure of oxygen, the first temperature of the mixture and the partial pressure of oxygen forming a reducing environment, the reducing environment forming a gaseous transport species of the metal;
- maintaining the surface of the substrate at a second temperature, the second temperature being less than the first temperature thereby defining a temperature gradient between the surface of the substrate and the mixture;
- and
- controlling the temperature gradient to provide transport of the gaseous transport species of the metal from the mixture to the substrate.
A method for forming a thin film of luminescent zinc oxide including the steps of:
- providing a mixture including powdered graphite and powdered zinc oxide, the powdered graphite being 20-80% by volume of the mixture;
- providing a substrate made from a material capable of withstanding high temperatures and having a surface, disposing said mixture and the surface of said substrate within a confined environment, the surface of the substrate being spaced from said mixture by a distance;
- heating the mixture to a first temperature within 700-1000 degrees Celsius;
- providing within the confined environment a partial pressure of oxygen, the first temperature of the mixture and the partial pressure of oxygen forming carbon monoxide, thereby providing a reducing environment forming a gaseous transport species of zinc;
- maintaining the surface of the substrate at a second temperature, the second temperature being less than the first temperature thereby defining a temperature gradient between the surface of the substrate and the mixture;
- and
- controlling the temperature gradient to provide transport of the gaseous transport species of the zinc from the mixture to the substrate.
Dependencies are inferred from the claim text.