Roger Thomas Howe

US Patent:

6448622, Sep 10, 2002

Filed:

Jul 17, 2000

Appl. No.:

09/617300

Inventors:

Andrea Franke - Oakland CA
Roger T. Howe - Martinez CA

Assignee:

The Regents of the University of California - Berkeley CA

International Classification:

H01L 2982

US Classification:

257415, 257414, 257616, 438 50, 438 53

Abstract:

This invention relates to micro-electromechanical systems using silicon-germanium films. Such a system includes one or more layers of Si Ge , deposited on a substrate, where 0x1. One or more transistors can be formed on the substrate.

US Patent:

6478974, Nov 12, 2002

Filed:

Jul 6, 1999

Appl. No.:

09/347903

Inventors:

Kyle S. Lebouitz - Albany CA
Roger T. Howe - Lafayette CA
Albert P. Pisano - Livermore CA

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

B01D 6700

US Classification:

216 2, 216 39, 216 56, 216 97

Abstract:

A method of fabricating a microfabricated filter. The method includes forming a frame structure and forming a plurality of openings through the frame structure. A permeable polysilicon membrane is formed over the plurality of openings through the frame structure. At least part of the sacrificial structure is etched with an etchant wherein the etchant passes through the permeable polysilicon membrane. The permeable polycrystal silicon membrane may have a thickness of between about 0. 05 micrometers and about 0. 30 micrometers.

US Patent:

6481285, Nov 19, 2002

Filed:

Apr 20, 2000

Appl. No.:

09/556023

Inventors:

Andrei M. Shkel - Irvine CA 92612
Roger T. Howe - Martinez CA 94553-9713

International Classification:

G01P 904

US Classification:

7350413

Abstract:

A micro-machined angle measurement gyroscope. In one implementation, the gyroscope includes a substrate; a proof mass coupled to the substrate by an isotropic suspension such that the proof mass can move in any direction in the plane of the substrate; a plurality of drive electrodes configured to cause the proof mass to oscillate in the plane of the substrate; and a plurality of sense electrodes configured to sense the motion of the proof mass in the plane of the substrate. In another implementation, the gyroscope includes a substrate; a proof mass suspended above the substrate by an isotropic suspension such that the proof mass can move in any direction in an oscillation plane normal to the substrate; a plurality of drive electrodes configured to cause the proof mass to oscillate in the oscillation plane; and a plurality of sense electrodes configured to sense the motion of the proof mass in the oscillation plane.

US Patent:

7151277, Dec 19, 2006

Filed:

Jul 3, 2003

Appl. No.:

10/613508

Inventors:

Di Gao - Albany CA, US
Roger T. Howe - Martinez CA, US
Roya Maboudian - Orinda CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H01L 29/04
H01L 29/76
H01L 29/26
H01L 31/12
H01L 33/00

US Classification:

257 51, 257 67, 257 72, 257 79

Abstract:

A method of etching silicon carbide using a nonmetallic mask layer. The method includes providing a silicon carbide substrate; forming a non-metallic mask layer by applying a layer of material on the substrate; patterning the mask layer to expose underlying areas of the substrate; and etching the underlying areas of the substrate with a plasma at a first rate, while etching the mask layer at a rate lower than the first rate.

US Patent:

7211926, May 1, 2007

Filed:

Feb 23, 2006

Appl. No.:

11/361814

Inventors:

Emmanuel P. Quevy - El Cerrito CA, US
Roger T. Howe - Los Gatos CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H03B 28/00
H03B 5/04

US Classification:

310315, 310309, 331 66, 331 69, 331108 D, 331155, 331156, 331177 R

Abstract:

Disclosed is an oscillator that relies on redundancy of similar resonators integrated on chip in order to fulfill the requirement of one single quartz resonator. The immediate benefit of that approach compared to quartz technology is the monolithic integration of the reference signal function, implying smaller devices as well as cost and power savings.

US Patent:

7256107, Aug 14, 2007

Filed:

May 3, 2005

Appl. No.:

11/121690

Inventors:

Hideki Takeuchi - El Cerrito CA, US
Emmanuel P. Quevy - Berkeley CA, US
Roger T. Howe - Martinez CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H01L 21/46
H01L 21/78
H01L 21/301

US Classification:

438460, 438113, 438933, 257E21017, 257E21127, 257E21229, 257E21237, 257E21304

Abstract:

In fabricating a microelectromechanical structure (MEMS), a method of forming a narrow gap in the MEMS includes a) depositing a layer of sacrificial material on the surface of a supporting substrate, b) photoresist masking and at least partially etching the sacrificial material to form at least one blade of sacrificial material, c) depositing a structural layer over the sacrificial layer, and d) removing the sacrificial layer including the blade of the sacrificial material with a narrow gap remaining in the structural layer where the blade of sacrificial material was removed.

US Patent:

7514853, Apr 7, 2009

Filed:

May 10, 2007

Appl. No.:

11/801774

Inventors:

Roger T. Howe - Los Gatos CA, US
Emmanuel P. Quevy - El Cerrito CA, US
David H. Bernstein - Oakland CA, US

Assignee:

Silicon Clocks, Inc. - Fremont CA

International Classification:

H01L 23/34

US Classification:

310346, 310328, 310315, 310338

Abstract:

A MEMS structure having a temperature-compensated resonating member is described. The MEMS structure comprises a stress inverter member coupled with a substrate. A resonating member is housed in the stress inverter member and is suspended above the substrate. The MEMS stress inverter member is used to alter the thermal coefficient of frequency of the resonating member by inducing a stress on the resonating member in response to a change in temperature.

US Patent:

7522019, Apr 21, 2009

Filed:

Jun 3, 2005

Appl. No.:

11/146303

Inventors:

Sunil A. Bhave - Ithaca NY, US
Roger T. Howe - Briones CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H03H 9/00
H03H 9/125

US Classification:

333187, 333188

Abstract:

An electrostatic transducer for micromechanical resonators, in which the electrode gaps are filled with a dielectric material having a much higher permittivity than air. This internal electrostatic transducer has several advantages over both air-gap electrostatic and piezoelectric transduction; including lower motional impedance, compatibility with advanced scaled CMOS device technology, and extended dynamic range. In one aspect, in order to minimize energy losses, the dielectric material has an acoustic velocity which is matched to that of the resonator material. Internal electrostatic transduction can be adapted to excite and detect either vertical modes (perpendicular to the substrate) or lateral modes (in the plane of the substrate). Its increased transduction efficiency is of particular importance for reducing the motional resistance of the latter.