Method and apparatus for a thin film dielectric stack
AssigneeBlackBerry Limited
InventorsMarina Zelner, Andrew Vladimir Claude Cervin, Edward Horne
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Abstract
A system that incorporates teachings of the subject disclosure may include, for example, a thin film capacitor having a substrate, a first electrode layer on the substrate, a first dielectric layer on the first electrode layer where the first dielectric layer has a columnar-oriented grain structure, a group of second dielectric layers stacked on the first dielectric layer where each of the group of second dielectric layers has a randomly-oriented grain structure, and a second electrode layer on the group of second dielectric layers. Other embodiments are disclosed.
Claims20
A method for fabricating a thin film capacitor, the method comprising:
- depositing a first dielectric layer on a first electrode layer utilizing a first process that is performed at a first temperature and that forms a columnar-oriented grain structure for the first dielectric layer;
- depositing a second dielectric layer on the first dielectric layer utilizing a second process that forms a randomly-oriented grain structure for the second dielectric layer;
- performing a first annealing at a second temperature that is higher than the first temperature;
- repeating the depositing and first annealing of the second dielectric layer until a desired thickness is obtained resulting in a group of second dielectric layers stacked directly on each other;
- performing a crystallization annealing at a third temperature;
- depositing a second electrode layer on the second dielectric layer;
- and
- performing a final crystallization annealing at a fourth temperature to form the thin film capacitor, wherein the fourth temperature is higher than the first, second and third temperatures.
A thin film capacitor comprising:
- a substrate;
- a first electrode layer on the substrate;
- a first dielectric layer on the first electrode layer, wherein the first dielectric layer has a columnar-oriented grain structure;
- a group of second dielectric layers stacked on the first dielectric layer, wherein the group of second dielectric layers is stacked directly on each other, wherein each of the group of second dielectric layers has a randomly-oriented grain structure, and wherein at least one of the group of second dielectric layers is formed from a different material from at least one other of the group of second dielectric layers;
- and
- a second electrode layer on the group of second dielectric layers.
A thin film capacitor comprising:
- a substrate;
- a first electrode layer on the substrate;
- a first dielectric layer on the first electrode layer, wherein the first dielectric layer has a columnar-oriented grain structure;
- a group of second dielectric layers stacked on the first dielectric layer, wherein the group of second dielectric layers is stacked directly on each other, wherein each of the group of second dielectric layers has a randomly-oriented grain structure, and wherein the first dielectric layer and at least one of the group of second dielectric layers comprises barium strontium titanate;
- and
- a second electrode layer on the group of second dielectric layers.
Dependencies are inferred from the claim text.