MULTI-BAND FILTER MODULE AND METHOD OF FABRICATING THE SAME

• US 20100058568A1
• Filed: 11/17/2009
• Published: 03/11/2010
• Est. Priority Date: 07/27/2006
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Song, In-sang, Park, Yun-kwon, Park, Eun-seok, Kim, Chul-soo, NAM, Kuang-woo
• Application Number:
  US12/620,264
• Publication Number:
  US 20100058568A1
• Time in Patent Office: Days
• US Class Current: 29/25.350
• 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 3/08 for the manufacture of resonators or networks using surface acoustic waves
• CPC Class Codes: H03H 9/105 the enclosure being defined by a cover cap mounted on an element forming part of the BAW device
• CPC Class Codes: H03H 9/1092 the enclosure being defined by a cover cap mounted on an element forming part of the surface acoustic wave [SAW] device on the side of the IDT's
• CPC Class Codes: H03H 9/46 Filters multiple-port electromechanical filters H03H9/70
• CPC Class Codes: H03H 9/54 comprising resonators of piezoelectric or electrostrictive material H03H9/64 takes precedence
• CPC Class Codes: H03H 9/64 using surface acoustic waves
• CPC Class Codes: H03H 9/703 Networks using bulk acoustic wave devices
• CPC Class Codes: H03H 9/706 Duplexers
• CPC Class Codes: H03H 9/72 Networks using surface acoustic waves
• CPC Class Codes: H03H 9/725 Duplexers
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

A multi-band filter module and a method of fabricating the same are provided. The multi-band filter module includes a piezoelectric substrate, a first filter provided on the piezoelectric substrate, and a second filter provided adjacent to the first filter on the piezoelectric substrate, and operating in a frequency band that is lower than that of the first filter.

Claims

1. A method of fabricating a multi-band filter module, the method comprising:

(a) forming a Film Bulk Acoustic Resonator (FBAR) on a piezoelectric substrate; and

(b) forming a Surface Acoustic Wave (SAW) device on the piezoelectric substrate;

wherein the steps (a) and (b) are concurrently performed.

2. The method of claim 1, wherein step (a) comprises:

(a1) forming a sacrificial layer, wherein the sacrificial layer is used to form an air gap to be recessed on a surface of the piezoelectric substrate;

(a2) sequentially depositing a first electrode, a piezoelectric plate, and a second electrode, on the piezoelectric substrate to form a resonant part;

(a3) depositing an electrode pad, which connects to the first and second electrodes; and

(a4) removing the sacrificial layer to form the air gap corresponding to the resonant part.

3. The method of claim 2, wherein step (b) comprises:

(b1) patterning the SAW device on the piezoelectric substrate; and

(b2) forming a SAW pad to be connected to the SAW device.

4. The method of claim 3, wherein step (b1) is performed at the same time as when the first electrode is formed in the (a2).

5. The method of claim 4, wherein step (b2) is performed concurrent with the step (a3).

6. he method of claim 3, wherein step (b2) is performed concurrent with step (a3).