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US 12,713,831 B2Granted
Fabrication of piezoelectric device with PMNPT layer
AssigneeApplied Materials, Inc.
InventorsAbhijeet Laxman Sangle, Vijay Bhan Sharma, Yuan Xue, Uday Pai, Bharatwaj Ramakrishnan, Ankur Kadam
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Abstract
A piezoelectric device includes a substrate, a thermal oxide layer on the substrate, a metal or metal oxide adhesion layer on the thermal oxide layer, a lower electrode on the metal oxide adhesion layer, a seed layer on the lower electrode, a lead magnesium niobate-lead titanate (PMNPT) piezoelectric layer on the seed layer, and an upper electrode on the PMNPT piezoelectric layer.
Claims12
A piezoelectric device, comprising:
- a substrate;
- a thermal oxide layer on a surface of the substrate;
- a metal adhesion layer on the thermal oxide layer, wherein the metal adhesion layer consists of metallic chromium, metallic nickel, or a metallic alloy of chromium and nickel;
- a lower electrode on the metal adhesion layer on the thermal oxide layer, wherein the metal adhesion layer and the lower electrode are composed of different materials;
- a seed layer on the lower electrode, wherein the seed layer is titanium oxide or niobium oxide;
- a lead magnesium niobate-lead titanate (PMNPT) piezoelectric layer on the seed layer,
- wherein the PMNPT piezoelectric layer is composed of columnar grains of <001> crystallographic orientation with respect to the surface of the substrate;
- and
- an upper electrode on the PMNPT piezoelectric layer.
6 more elements
A method of fabricating a piezoelectric device, comprising:
- forming, on a surface of a substrate, an adhesion layer on a thermal layer of the substrate by depositing metallic titanium, metallic chromium, metallic nickel, or a metallic combination thereof;
- depositing a lower electrode on the adhesion layer, wherein the adhesion layer and the lower electrode are composed of different materials;
- forming a seed layer on the lower electrode, wherein the seed layer is titanium oxide or niobium oxide;
- depositing a lead magnesium niobate-lead titanate (PMNPT) piezoelectric layer on the seed layer by physical vapor deposition, wherein PMNPT piezoelectric layer is composed of columnar grains of <001> crystallographic orientation with respect to the surface of the substrate after deposition;
- and
- depositing an upper electrode on the PMNPT piezoelectric layer.
3 more elements
A piezoelectric device, comprising:
- a single crystal silicon wafer having a <001> crystallographic orientation with respect to a surface of the single crystal silicon wafer;
- a silicon oxide layer on the single crystal silicon wafer;
- a titanium oxide adhesion layer on the silicon oxide layer, the titanium oxide adhesion layer having a thickness of 25-40 nm;
- a platinum lower electrode of <111> crystallographic orientation on the titanium oxide adhesion layer;
- a seed layer on the platinum lower electrode, the seed layer consisting of titanium oxide and having a thickness of 1-5 nm;
- a lead magnesium niobate-lead titanate (PMNPT) piezoelectric layer of <001> crystallographic orientation with respect to the surface of the single crystal silicon wafer on the seed layer;
- and
- a platinum upper electrode with a first surface contacting the PMNPT piezoelectric layer,
- wherein a second surface of the platinum upper electrode opposite the first surface is an exposed surface of the piezoelectric device.
6 more elements
Dependencies are inferred from the claim text.