James W Logsdon

US Patent:

6793389, Sep 21, 2004

Filed:

Oct 18, 2002

Appl. No.:

10/065447

Inventors:

Abhijeet V. Chavan - Carmel IN
James H. Logsdon - Kokomo IN
Dan W. Chilcott - Greentown IN
Han-Sheng S. Lee - Bloomfield Hills MI
David K. Lambert - Sterling Heights MI
Timothy A. Vas - Kokomo IN

Assignee:

Delphi Technologies, Inc. - Troy MI

International Classification:

G01K 702

US Classification:

374179, 374163, 374183, 374121, 136213

Abstract:

An integrated sensor comprising a thermopile transducer and signal processing circuitry that are combined on a single semiconductor substrate, such that the transducer output signal is sampled in close vicinity by the processing circuitry. The sensor comprises a frame formed of a semiconductor material that is not heavily doped, and with which a diaphragm is supported. The diaphragm has a first surface for receiving thermal (e. g. , infrared) radiation, and comprises multiple layers that include a sensing layer containing at least a pair of interlaced thermopiles. Each thermopile comprises a sequence of thermocouples, each thermocouple comprising dissimilar electrically-resistive materials that define hot junctions located on the diaphragm and cold junctions located on the frame. The signal processing circuitry is located on the frame and electrically interconnected with the thermopiles. The thermopiles are interlaced so that the output of one of the thermopiles increases with increasing temperature difference between the hot and cold junctions thereof, while the output of the second thermopile decreases with increasing temperature difference between its hot and cold junctions.

US Patent:

6828172, Dec 7, 2004

Filed:

Oct 18, 2002

Appl. No.:

10/065448

Inventors:

Abhijeet V. Chavan - Carmel IN
James H. Logsdon - Kokomo IN
Dan W. Chilcott - Greentown IN
John C. Christenson - Kokomo IN
Robert K. Speck - Kokomo IN

Assignee:

Delphi Technologies, Inc. - Troy MI

International Classification:

H01I 2100

US Classification:

438 50, 438 53, 438756

Abstract:

A process using integrated sensor technology in which a micromachined sensing element and signal processing circuit are combined on a single semiconductor substrate to form, for example, an infrared sensor. The process is based on modifying a CMOS process to produce an improved layered micromachined member, such as a diaphragm, after the circuit fabrication process is completed. The process generally entails forming a circuit device on a substrate by processing steps that include forming multiple dielectric layers and at least one conductive layer on the substrate. The dielectric layers comprise an oxide layer on a surface of the substrate and at least two dielectric layers that are in tension, with the conductive layer being located between the two dielectric layers. The surface of the substrate is then dry etched to form a cavity and delineate the diaphragm and a frame surrounding the diaphragm. The dry etching step terminates at the oxide layer, such that the diaphragm comprises the dielectric layers and conductive layer.

US Patent:

20050064619, Mar 24, 2005

Filed:

Sep 30, 2004

Appl. No.:

10/955128

Inventors:

Abhijeet Chavan - Carmel IN, US
James Logsdon - Kokomo IN, US
Dan Chilcott - Greentown IN, US
John Christenson - Kokomo IN, US
Robert Speck - Kokomo IN, US

International Classification:

H01L021/00

US Classification:

438052000

Abstract:

A process using integrated sensor technology in which a micromachined sensing element and signal processing circuit are combined on a single semiconductor substrate to form, for example, an infrared sensor. The process is based on modifying a CMOS process to produce an improved layered micromachined member, such as a diaphragm, after the circuit fabrication process is completed. The process generally entails forming a circuit device on a substrate by processing steps that include forming multiple dielectric layers and at least one conductive layer on the substrate. The dielectric layers comprise an oxide layer on a surface of the substrate and at least two dielectric layers that are in tension, with the conductive layer being located between the two dielectric layers. The surface of the substrate is then dry etched to form a cavity and delineate the diaphragm and a frame surrounding the diaphragm. The dry etching step terminates at the oxide layer, such that the diaphragm comprises the dielectric layers and conductive layer. A special absorber is preferably fabricated on the diaphragm to promote efficient absorption of incoming infrared radiation.