Process for fabricating device comprising lead zirconate titanate

• US 6,248,394 B1
• Filed: 01/22/1999
• Issued: 06/19/2001
• Est. Priority Date: 08/14/1998
• Status: Expired due to Term

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global))
• Original Assignee: Agere Systems Guardian Corp. (Broadcom, Inc.)
• Inventors: Du, Honghua, Jin, Sungho, Zhu, Wei, Johnson, David Wilfred Jr., Graebner, John Edwin
• Primary Examiner(s): Beck, Shrive
• Assistant Examiner(s): Strain, Paul D.
• Application Number:
  US09/235,735
• Time in Patent Office: 879 Days
• Field of Search: 427/255.32, 427/561, 427/596, 204/192.18, 204/192.2, 204/192.22
• US Class Current: 427/100
• CPC Class Codes: H10N 30/076 by vapour phase deposition
• CPC Class Codes: H10N 30/079 using intermediate layers, e.g. for growth control

Abstract

The invention provides a device comprising an oriented, perovskite PZT layer on a diamond substrate, or other substrates such as silicon or platinum-coated materials. Vapor phase deposition processes are used to deposit a PZT layer onto a perovskite template layer on the substrate. The template layer is more readily deposited in a perovskite structure compared to PZT, and provides for nucleation and growth of the deposited PZT in perovskite form. The vapor phase deposition promotes the oriented structure of the resulting film. The structure is useful in a variety of devices, including surface acoustic wave devices.

Claims

1. A process for fabricating a device, comprising the steps of:

providing a diamond substrate;

depositing an oriented perovskite template layer comprising lead titanate, strontium titanate, or barium titanate directly onto the substrate;

depositing a layer of lead zirconate titanate onto the template layer by a vapor phase deposition method, wherein the template layer induces oriented nucleation and growth of the lead zirconate titanate layer, such that the lead zirconate titanate layer is an oriented, perovskite layer exhibiting a piezoelectric coefficient of about 50×

10<sup>−

12</sup> to about 350×

10<sup>−

12</sup> m/V.

2. The process of claim 1, wherein the template layer is deposited by a vapor phase deposition method.

3. The process of claim 1, wherein the template layer is lead titanate and has a thickness of about 0.06 to about 0.12 μ

m.

4. The process of claim 1, wherein the lead zirconate titanate layer has a thickness of about 0.1 to about 5 μ

m.

5. The process of claim 1, wherein the vapor phase deposition method for the lead zirconate titanate layer is physical vapor deposition or chemical vapor deposition.

6. The process of claim 2, wherein the vapor phase deposition method for the template layer is physical vapor deposition or chemical vapor deposition.

7. The process of claim 1, wherein the dielectric constant of the lead titanate zirconate layer is about 500 to about 650 at 1 V and 100 kHz.

8. The process of claim 1, wherein the device is an acoustic resonator device.