Method for enhancing aluminum nitride
AssigneeMotorola, Inc.
InventorsKeenan L. Evans, Hang M. Liaw, Jong-Kai Lin
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Abstract
A method for enhancing aluminum nitride includes, in one version, annealing sputtered aluminum nitride in a reducing atmosphere (11), and subsequently annealing the sputtered aluminum nitride in an inert atmosphere (12). A superior aluminum nitride thin film (13) results. The films can withstand exposure to boiling water for times up to twenty minutes and maintain a refractive index, N.sub.f, greater than 2.0, and a preferred crystalline orientation ratio, I(002)/I(102), in excess of 1000.
Claims18
A method for enhancing chemical stability and crystalline and piezoelectric properties of aluminum nitride including the steps of:
- sputtering an aluminum nitride layer on a surface, the aluminum nitride layer having a thickness of at least 5000 .ANG.;
- and
- annealing the sputtered aluminum nitride to form an enhanced aluminum nitride;
- wherein the enhanced aluminum nitride has a refractive index of at least 85% of a refractive index of the aluminum nitride layer.
A method for enhancing chemical stability, crystalline and piezoelectric properties of sputtered aluminum nitride including the steps of:
- annealing the sputtered aluminum nitride in a first ambient;
- and
- subsequently, annealing the sputtered aluminum nitride in a second ambient,
- wherein after annealing the sputtered aluminum nitride in the second ambient, the sputtered aluminum nitride has a refractive index of at least 85% of a refractive index of the sputtered aluminum nitride before annealing in the first ambient.
Dependencies are inferred from the claim text.