Bulk acoustic resonator and filter including the same

Patent metadata

Field	Value
Publication number	US-2020366265-A1
Application number	US-202016983209-A
Country	US
Kind code	A1
Filing date	Aug 3, 2020
Priority date	Aug 26, 2016
Publication date	Nov 19, 2020
Grant date	—

Abstract

A bulk acoustic resonator includes: a substrate including an upper surface on which a substrate protection layer is disposed; and a membrane layer forming a cavity together with the substrate, wherein a thickness deviation of either one or both of the substrate protection layer and the membrane layer is 170 Å or less.

First claim

What is claimed is:

1 . A bulk acoustic resonator, comprising:
a substrate comprising an upper surface on which a substrate protection layer is disposed; and a membrane layer forming a cavity together with the substrate, wherein a thickness of either one or both of the substrate protective layer and the membrane layer increases from an edge of an active region of the bulk acoustic resonator to a center of the active region.

2 . The bulk acoustic resonator of claim 1 , wherein a thickness deviation of either one or both of the substrate protection layer and the membrane layer is 170 Å or less.

3 . The bulk acoustic resonator of claim 1 , wherein either one or both of the substrate protection layer and the membrane layer comprise:
a dielectric layer comprising any one or any combination of any two or more of manganese oxide (MgO), zirconium oxide (ZrO 2 ), aluminum nitride (AlN), lead zirconate titanate (PZT), gallium arsenide (GaAs), hafnium oxide (HfO 2 ), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), and zinc oxide (ZnO); or a metal layer comprising any one or any combination of any two or more of aluminum (Al), nickel (Ni), chromium (Cr), platinum (Pt), gallium (Ga), and hafnium (Hf).

4 . The bulk acoustic resonator of claim 3 , wherein the membrane layer comprises the dielectric layer, and the substrate protection layer comprises either one of silicon nitride and silicon oxide.

5 . The bulk acoustic resonator of claim 3 , wherein the substrate protection layer comprises the dielectric layer, and the membrane layer comprises either one of silicon nitride and silicon oxide.

6 . The bulk acoustic resonator of claim 1 , further comprising:
a lower electrode disposed on the membrane layer; a piezoelectric layer configured to partially cover the lower electrode; and an upper electrode disposed on the piezoelectric layer.

7 . The bulk acoustic resonator of claim 6 , further comprising:
a passivation layer disposed on portions of the upper and lower electrodes; and a metal pad formed on other portions of the upper and lower electrodes on which the passivation layer is not formed.

8 . The bulk acoustic resonator of claim 6 , wherein the upper electrode comprises a frame portion disposed at the edge of the active region.

9 . A bulk acoustic resonator, comprising:
a substrate comprising an upper surface on which a substrate protection layer is formed; and a membrane layer forming a cavity together with the substrate, wherein either one or both of the substrate protection layer and the membrane layer comprise: a dielectric layer comprising any one or any combination of any two or more of manganese oxide (MgO), zirconium oxide (ZrO 2 ), aluminum nitride (AlN), lead zirconate titanate (PZT), gallium arsenide (GaAs), hafnium oxide (HfO 2 ), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), and zinc oxide (ZnO); or a metal layer comprising any one or any combination of any two or more of aluminum (Al), nickel (Ni), chromium (Cr), platinum (Pt), gallium (Ga), and hafnium (Hf), wherein a thickness of one or both of the substrate protective layer and the membrane layer increases from an edge of an active region of the bulk acoustic resonator to a center of the active region.

10 . The bulk acoustic resonator of claim 9 , further comprising:
a lower electrode disposed on the membrane layer; a piezoelectric layer configured to partially cover the lower electrode; and an upper electrode disposed on the piezoelectric layer.

11 . The bulk acoustic resonator of claim 10 , further comprising:
a passivation layer disposed on portions of the upper and lower electrodes; and a metal pad disposed on other portions of the upper and lower electrodes on which the passivation layer is not formed.

12 . The bulk acoustic resonator of claim 9 , wherein a thickness deviation of either one or both of the substrate protection layer and the membrane layer is 170 Å or less.

13 . A filter, comprising:
bulk acoustic resonators, wherein each of the bulk acoustic resonators comprises:
a substrate comprising an upper surface on which a substrate protection layer is disposed; and
a membrane layer forming a cavity together with the substrate,
wherein a thickness of one or both of the substrate protective layer and the membrane layer increases from an edge of an active region of the bulk acoustic resonator to a center of the active region, wherein a thickness deviation of either one or both of the substrate protection layer and the membrane layer is 170 Å or less, and wherein the bulk acoustic resonators are connected to each other in series or in parallel.

Assignees

• Samsung Electro Mech

Inventors

• Lee Tae Kyung
• Kim Tae Yoon
• Kim Dae Ho
• Lim Chang Hyun
• Lee Tae Hun
• Yoon Sang Kee
• Kim Jong Woon
• Han Won
• Lee Moon Chul

Classifications

• H03H2003/021

  the resonators or networks being of the air-gap type · CPC title

• H03H9/605

  consisting of a ladder configuration · CPC title

• H03H9/568

  consisting of a ladder configuration · CPC title

• H03H9/562

  comprising a ceramic piezoelectric layer · CPC title

• H03H9/547 Primary

  Notch filters, e.g. notch BAW or thin film resonator filters · CPC title