Piezoelectric thin film stack

Patent metadata

Field	Value
Publication number	US-2016240769-A1
Application number	US-201315026311-A
Country	US
Kind code	A1
Filing date	Oct 30, 2013
Priority date	Oct 30, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

The present disclosure is drawn to a piezoelectric thin film stack and method of preparing the same. The piezoelectric thin film stack can comprise a substrate with an oxide application surface, a metal oxide adhesive blend layer applied to the oxide application surface, and a piezoelectric film applied directly to the metal oxide adhesive blend layer.

First claim

1 . A piezoelectric thin film stack, comprising a substrate with an oxide application surface, a metal oxide adhesive blend layer applied to the oxide application surface, and a piezoelectric film applied directly on and adhered to the metal oxide adhesive blend layer.

2 . The piezoelectric thin film stack of claim 1 , wherein the metal oxide adhesive blend layer includes from 3 at % to 97 at % zinc oxide and 3 at % to 97 at % tin oxide, and wherein the zinc oxide and the tin oxide collectively comprise from 90 at % to 100 at % of the metal oxide adhesive blend layer.

3 . The piezoelectric thin film stack of claim 1 , wherein the metal oxide adhesive blend layer includes from 3 at % to 94 at % indium oxide, from 3 at % to 94 at % gallium oxide, and from 3 at % to 94 at % zinc oxide, and wherein the indium oxide, gallium oxide, and zinc oxide collectively comprise from 90 at % to 100 at % of the metal oxide adhesive blend layer.

4 . The piezoelectric thin film stack of claim 1 , wherein the piezoelectric film is lead zirconate titanate (PZT).

5 . The piezoelectric thin film stack of claim 1 , further including a first metallic layer or feature applied directly to the metal oxide adhesive blend layer such that the piezoelectric film and the metallic layer or feature coexist on a common metal oxide adhesive blend layer.

6 . The piezoelectric thin film stack of claim 5 , further comprising a second metallic layer or feature applied to the piezoelectric film, and wherein the piezoelectric film is adapted to provide both piezoelectric actuation and electrical insulation between the first metallic layer or feature and the second metallic layer or feature.

7 . The thin film stack of claim 5 , wherein the first metallic layer or feature is a metal or metal oxide electrode from 5 nm to 5 microns in thickness, and is selected from the group of platinum, ruthenium, palladium, iridium IrO 2 , and SrRuO 3 .

8 . The piezoelectric thin film stack of claim 1 , further comprising a pair of electrodes both present on a common surface of the piezoelectric film, wherein the electrodes are positioned and adapted to generate piezoelectric actuation or sensing using the piezoelectric material.

9 . The piezoelectric thin film stack of claim 1 , wherein the piezoelectric thin film stack is an actuator for a fluid ejection device.

10 . The thin film stack of claim 1 , wherein the metal oxide adhesive blend layer includes at least two metal oxides selected from the group consisting of zinc oxide, tin oxide, gallium oxide, and indium oxide.

11 . A method of preparing a piezoelectric thin film stack, comprising:
depositing a metal oxide adhesive blend layer to an oxide application surface of a substrate; depositing a piezoelectric film directly on and adhered to the metal oxide adhesive blend layer.

12 . The method of claim 11 , further comprising intermediate steps of:
applying a metallic layer directly to the metal oxide adhesive blend layer: and etching away a portion of the metallic layer to form a first metallic feature prior to depositing the piezoelectric film directly to the metal oxide adhesive blend layer, thereby forming a piezoelectric film that is directly applied to both the metal oxide adhesive blend layer and the metallic feature.

13 . The method of claim 12 , further comprising the step of applying a second metallic feature to an upper surface of the piezoelectric film, wherein the first metallic feature and the second metallic feature are electrically insulated from one another by the piezoelectric film.

14 . The method of claim 11 , further comprising the step of annealing the metal oxide adhesive blend layer at from room temperature to 1000° C. in a furnace or a rapid thermal processing system.

15 . The method of claim 11 , wherein the metal oxide adhesive blend layer includes at least two metal oxides selected from the group consisting of zinc oxide, tin oxide, gallium oxide, and indium oxide, and wherein the piezoelectric film is lead zirconate titanate (PZT).

16 . The piezoelectric thin film stack of claim 1 , further comprising a pair of interdigitated electrodes each having interlaced digits deposited on top of the piezoelectric film, wherein the pair of interdigitated electrodes alloy a d 33 piezoelectric coefficient to dominate over a d 31 piezoelectric coefficient response of the piezoelectric film by eliminating an electrode between the piezoelectric film and the metal oxide adhesive layer.

17 . The piezoelectric thin film stack of claim 1 , further comprising a pair of interdigitated electrodes each having interlaced digits deposited on top of the metal oxide adhesive layer, wherein the pair of interdigitated electrodes allow a d 33 piezoelectric coefficient to dominate over a d 31 piezoelectric coefficient response of the piezoelectric film by eliminating an electrode on top of the piezoelectric film.

18 . The piezoelectric thin film stack of claim 17 wherein the piezoelectric film comprises lead zirconate titanate (PZT).

19 . The method of claim 11 , further comprising depositing on top of the piezoelectric film a pair of interdigitated electrodes each having interlaced digits, wherein the pair of interdigitated electrodes allow a d 33 piezoelectric coefficient to dominate over a d 31 piezoelectric coefficient response of the piezoelectric, film by eliminating an electrode between the piezoelectric film and the metal oxide adhesive layer.

20 . The method of claim 11 , further comprising depositing on top of the metal oxide adhesive layer a pair of interdigitated electrodes each having interlaced digits, wherein the pair of interdigitated electrodes allow a d 33 piezoelectric coefficient to dominate over a d 31 piezoelectric coefficient response of the piezoelectric film by eliminating an electrode on top of the piezoelectric film.

Assignees

• Hewlett Packard Development Co Lp
• The State of Oregon acting by and through the State Board of Higher Education on behalf of Orego

Inventors

• Abbott Jr James Elmer
• Mardilovich Peter
• Gibbons Brady
• Maack Bryan Alexander

Classifications

• B41J2/14274

  of stacked structure type, deformed by compression/extension and disposed on a diaphragm · CPC title

• B41J2/1645

  thin film formation by spincoating · CPC title

• B41J2/1631

  photolithography · CPC title

• B41J2/161

  of film type, deformed by bending and disposed on a diaphragm · CPC title

• B41J2/1626

  etching · CPC title