METHOD OF FABRICATING PIEZOELECTRIC MATERIAL WITH SELECTED C-AXIS ORIENTATION

• US 20110180391A1
• Filed: 01/22/2010
• Published: 07/28/2011
• Est. Priority Date: 01/22/2010
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies Wireless IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Larson, John III, Mishin, Sergey
• Granted Patent: US 9,243,316 B2
• Time in Patent Office: Days
• US Class Current: 204/192.18
• CPC Class Codes: C23C 14/0036 Reactive sputtering
• CPC Class Codes: C23C 14/02 Pretreatment of the material to be coated C23C14/04 takes precedence
• CPC Class Codes: C23C 14/022 by means of bombardment with energetic particles or radiation
• CPC Class Codes: C23C 14/0617 AIII BV compounds, where A is Al, Ga, In or Tl and B is N, P, As, Sb or Bi
• CPC Class Codes: C23C 14/0641 Nitrides C23C14/0617 takes precedence
• CPC Class Codes: C23C 14/228 Gas flow assisted PVD deposition
• CPC Class Codes: C23C 14/345 using substrate bias
• CPC Class Codes: H03H 2003/0071 of bulk acoustic wave and surface acoustic wave elements in the same process
• CPC Class Codes: H03H 3/02 for the manufacture of piezoelectric or electrostrictive resonators or networks H03H3/08 takes precedence
• CPC Class Codes: H03H 9/02015 Characteristics of piezoelectric layers, e.g. cutting angles
• CPC Class Codes: H03H 9/205 having multiple resonators crystal tuning forks H03H9/21

Abstract

In accordance with a representative embodiment, a method of fabricating a piezoelectric material comprising a first component and a second component comprises: providing a substrate; flowing hydrogen over the substrate; flowing the first component to form the piezoelectric material over a target; and sputtering the piezoelectric material from the target on the substrate. In accordance with another representative embodiment, a method of fabricating a bulk acoustic wave (BAW) resonator comprises: forming a first electrode over a substrate; forming a seed layer over the substrate; and depositing a piezoelectric material having a compression-negative (C_N) polarity. The depositing of the piezoelectric material comprises: flowing a first component of the piezoelectric material to form the piezoelectric material over a target comprising a second component of the piezoelectric material; and sputtering the piezoelectric material from the target to the substrate.

Claims

1. A method of fabricating a piezoelectric material comprising a first component and a second component, the method comprising:

providing a substrate;

flowing hydrogen over the substrate; and

flowing the first component to form the piezoelectric material over a target; and

sputtering the piezoelectric material from the target on the substrate.

2. A method of fabricating a piezoelectric material as claimed in claim 1, wherein the piezoelectric film comprises a compression-negative (C_N) polarity.

3. A method of fabricating a piezoelectric material as claimed in claim 1, wherein the flowing of hydrogen is continuous during the fabricating of the piezoelectric film

4. A method of fabricating a piezoelectric material as claimed in claim 1, further comprising, after the depositing:

ceasing flow of the hydrogen;

forming a second substrate over the piezoelectric film; and

sputtering the piezoelectric material from the target over the second substrate.

5. A method of fabricating a piezoelectric material as claimed in claim 4, further comprising, before forming the second substrate flowing hydrogen over the second substrate, wherein the piezoelectric material comprises a compression-negative (C_N) material.

6. A method of fabricating a piezoelectric material as claimed in claim 3, wherein the substrates comprise a metal.

7. A method of fabricating a piezoelectric material as claimed in claim 6, wherein the metal comprises one of:

molybdenum (Mo), aluminum (Al), tungsten (W), platinum (Pt), and ruthenium (Ru).

8. A method of fabricating a piezoelectric material as claimed in claim 1, wherein the first component comprises nitrogen and the second component comprises aluminum.

9. A method of fabricating a piezoelectric material as claimed in claim 4, wherein the piezoelectric material sputtered on the first substrate comprises a compression-negative (C_N) material, and the piezoelectric material sputtered over the second substrate comprises a compression-positive (C_P) material.

10. A method of fabricating a piezoelectric material as claimed in claim 1, wherein the flowing of hydrogen during the depositing forms NH_x.

20. A method of fabricating a BAW resonator as claimed in claim 10, wherein the first component comprises nitrogen and the second component comprises aluminum.

11. A method of fabricating a bulk acoustic wave (BAW) resonator, the method comprising:

forming a first electrode over a substrate;

forming a seed layer over the substrate;

depositing a piezoelectric material having a compression-negative (C_N) polarity, the depositing comprising;

flowing a first component of the piezoelectric material to form the piezoelectric material over a target comprising a second component of the piezoelectric material; and

sputtering the piezoelectric material from the target to the substrate.

12. A method as of fabricating a BAW resonator as claimed in claim 11, further comprising forming a second electrode over the piezoelectric material.

13. A method as of fabricating a BAW resonator as claimed in claim 11, wherein the seed layer comprises aluminum.

14. A method of fabricating a BAW resonator as claimed in claim 13, wherein the first electrode and the second electrode comprise one of molybdenum (Mo), aluminum (Al), tungsten (W), platinum (Pt), and ruthenium (Ru).

15. A method of fabricating a BAW resonator as claimed in claim 11, further comprising, after the forming of the first electrode and before the forming of the seed layer, forming a plasma and removing a contaminant from a surface of the first electrode.

16. A method of fabricating a BAW resonator as claimed in claim 11, further comprising, after the forming of the seed layer, maintaining a flow of an inert gas over the surface of the seed layer during the depositing of the first component and the piezoelectric material.

17. A method of fabricating a BAW resonator as claimed in claim 11, further comprising, after the depositing of the piezoelectric material:

sputtering a second piezoelectric material over the second electrode, wherein the second piezoelectric material comprises a compression-positive (C_P) polarity.

18. A method of fabricating a BAW resonator as claimed in claim 11, wherein the first electrode and the second electrode comprise a metal.

19. A method of fabricating a BAW resonator as claimed in claim 18, wherein the metal comprises one of:

molybdenum (Mo), aluminum (Al), tungsten (W), platinum (Pt), and ruthenium (Ru).