Richard R Ruby

US Patent:

6376280, Apr 23, 2002

Filed:

Oct 8, 1999

Appl. No.:

09/415284

Inventors:

Richard C. Ruby - Menlo Park CA
Tracy E. Bell - Campbell CA
Frank S. Geefay - Cupertino CA
Yogesh M. Desai - San Jose CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

H01L 2144

US Classification:

438118, 438110, 438455, 438612

Abstract:

A microcap wafer-level package is provided in which a micro device is connected to bonding pads on a base wafer. A peripheral pad on the base wafer encompasses the bonding pads and the micro device. A cap wafer has gaskets formed thereon using a thick photoresist semiconductor photolithographic process. Bonding pad gaskets match the perimeters of the bonding pads and a peripheral pad gasket matches the peripheral pad on the base wafer. Wells are located inside the perimeters of the bond pad gaskets and are formed to a predetermined depth in the cap wafer. The cap wafer is then placed over the base wafer to cold weld bond the gaskets to the pads and form a hermetically sealed volume between the bonding pad gaskets and the peripheral pad gasket. The cap wafer is then thinned below the predetermined depth until the wells become through holes that provide access to the bonding pads inside the package, but outside the hermetically sealed volume, for connecting wires from a micro device utilizing system.

US Patent:

6377137, Apr 23, 2002

Filed:

Sep 11, 2000

Appl. No.:

09/659254

Inventors:

Richard C. Ruby - Menlo Park CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

H03H 954

US Classification:

333189, 333187, 310321, 310324, 310348, 29 2535, 438959

Abstract:

A plurality of acoustic resonators are manufactured in a batch process by forming cavities in a substrate and filling the cavities with a sacrificial layer. An FBAR membrane comprising a bottom electrode, a piezoelectric layer, and a top electrode is formed over each cavity and the sacrificial layer. The substrate is then thinned and the substrate is separated into a plurality of dice using a scribe and break process. The sacrificial layer is then removed and the FBAR filter is mounted in a package with thermal vias being thermal communication with underside of the FBAR filter. The production method improves thermal properties by increasing the efficiency of heat dissipation from the FBAR filter. In addition, electromagnetic interference is decreased by reducing the distance between a primary current flowing over the surface of the FBAR filter and an image current flowing in a ground plane beneath the FBAR filter.

US Patent:

6384697, May 7, 2002

Filed:

May 8, 2000

Appl. No.:

09/566868

Inventors:

Richard C. Ruby - Menlo Park CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

H03H 900

US Classification:

333189, 333187

Abstract:

A filter formed of acoustic resonators, where each resonator has its own cavity and a bottom electrode that spans the entirety of the cavity, so that the bottom electrode has an unsupported interior region surrounded by supported peripheral regions. In the preferred embodiment, the cavity is formed by etching a depression into the substrate, filling the depression with a sacrificial material, depositing the piezoelectric and electrode layers that define an FBAR or SBAR, and then removing the sacrificial material from the depression. Also in the preferred embodiment, the sacrificial material is removed via release holes that are limited to the periphery of the depression. Preferably, the bottom electrode is the only electrode that spans the cavity, thereby limiting the formation of parasitic FBARs or SBARs. In one embodiment, the bottom electrode includes a serpentine edge that leaves a portion of one side of the cavity free of overlap by the bottom electrode, so that a top electrode may overlap this portion. Thus, the top and bottom electrodes can overlap the same side without sandwiching the piezoelectric layer outside of the unsupported interior region.

US Patent:

6424237, Jul 23, 2002

Filed:

Dec 21, 2000

Appl. No.:

09/746525

Inventors:

Richard C. Ruby - Menlo Park CA
Paul D. Bradley - Mountian View CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

H03H 915

US Classification:

333187, 333191, 310324, 310365, 310349, 29 2535

Abstract:

A bulk acoustic resonator having a high quality factor is formed on a substrate having a depression formed in a top surface of the substrate. The resonator includes a first electrode, a piezoelectric material and a second electrode. The first electrode is disposed on the top surface of the substrate and extends beyond the edges of the depression by a first distance to define a first region therebetween. The piezoelectric material is disposed on the top surface of the substrate and over the first electrode, and the second electrode is disposed on the piezoelectric material. The second electrode includes a portion that is located above the depression. The portion of the second electrode that is located over the depression has at least one edge that is offset from a corresponding edge of the depression by a second distance to define a second region therebetween. The first and second regions have different impedances, as a result of the different materials located in the two regions. In addition, the first and second distances are approximately equal to a quarter-wavelength of a sound wave travelling laterally across the respective region, such that reflections off of the edges of the regions constructively interfere to maximize the reflectivity of the resonator.

US Patent:

6429511, Aug 6, 2002

Filed:

Oct 1, 2001

Appl. No.:

09/969432

Inventors:

Richard C. Ruby - Menlo Park CA
Tracy E. Bell - Campbell CA
Frank S. Geefay - Cupertino CA
Yogesh M. Desai - San Jose CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

H01L 2348

US Classification:

257704, 257685, 257686, 257723, 257777

Abstract:

A microcap wafer-level package is provided in which a micro device is connected to bonding pads on a base wafer. A peripheral pad on the base wafer encompasses the bonding pads and the micro device. A cap wafer has gaskets formed thereon using a thick photoresist semiconductor photolithographic process. Bonding pad gaskets match the perimeters of the bonding pads and a peripheral pad gasket matches the peripheral pad on the base wafer. Wells are located inside the perimeters of the bond pad gaskets and are formed to a predetermined depth in the cap wafer. The cap wafer is then placed over the base wafer to cold weld bond the gaskets to the pads and form a hermetically sealed volume between the bonding pad gaskets and the peripheral pad gasket. The cap wafer is then thinned below the predetermined depth until the wells become through holes that provide access to the bonding pads inside the package, but outside the hermetically sealed volume, for connecting wires from a micro device utilizing system.

US Patent:

6462631, Oct 8, 2002

Filed:

Feb 14, 2001

Appl. No.:

09/783773

Inventors:

Paul Bradley - Mountain View CA
Richard C. Ruby - Menlo Park CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

H03H 958

US Classification:

333189, 333187

Abstract:

A filter, such as a transmit filter of a duplexer, includes an array of acoustic resonators that cooperate to establish an asymmetrically shaped filter response over a target frequency passband. The acoustic resonators are preferably film bulk acoustic resonators (FBARs). The filter response defines an insertion loss profile in which a minimum insertion loss within the target passband is located at or near a first end of the frequency passband, while the maximum insertion loss is located at or near the opposite end of the frequency passband. In the transmit filter embodiment, the minimum insertion loss is at or near the high frequency end of the filter response, which is tailored by selectively locating poles and zeros of the array of FBARs.

US Patent:

6469597, Oct 22, 2002

Filed:

Mar 5, 2001

Appl. No.:

09/799204

Inventors:

Richard C. Ruby - Menlo Park CA
Paul D. Bradley - Mountain View CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

H03H 956

US Classification:

333187, 333188, 333191, 310312, 29 2535

Abstract:

A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. An FBAR is fabricated on a substrate by introducing a mass loading electrode to a bottom electrode layer. For a substrate having multiple resonators, mass loading bottom electrode is introduced for only selected resonator to provide resonators having different resonance frequencies on the same substrate.

US Patent:

6472954, Oct 29, 2002

Filed:

Apr 23, 2001

Appl. No.:

09/841234

Inventors:

Richard C. Ruby - Menlo Park CA
Paul Bradley - Mountain View CA
Domingo Figueredo - Livermore CA
Yury Oshmyansky - Camarillo CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

H03H 9205

US Classification:

333133, 333188, 29 2535, 310312, 310364

Abstract:

In an array of acoustic resonators, the effective coupling coefficient of first and second filters are individually tailored in order to achieve desired frequency responses. In a duplexer embodiment, the effective coupling coefficient of a transmit band-pass filter is lower than the effective coupling coefficient of a receive band-pass filter of the same duplexer. In one embodiment, the tailoring of the coefficients is achieved by varying the ratio of the thickness of a piezoelectric layer to the total thickness of electrode layers. For example, the total thickness of the electrode layers of the transmit filter may be in the range of 1. 2 to 2. 8 times the total thickness of the electrode layers of the receive filter. In another embodiment, the coefficient tailoring is achieved by forming a capacitor in parallel with an acoustic resonator within the filter for which the effective coupling coefficient is to be degraded. Preferably, the capacitor is formed of the same materials used to fabricate a film bulk acoustic resonator (FBAR).