MEMS pressure sensing array with leaking sensor

• US 7,021,151 B1
• Filed: 10/29/2004
• Issued: 04/04/2006
• Est. Priority Date: 10/29/2004
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Hopper, Peter J., Drury, Robert, Mian, Michael, McGinty, Jim
• Primary Examiner(s): Lefkowitz, Edward
• Assistant Examiner(s): ALLEN, ANDRE J
• Application Number:
  US10/977,169
• Time in Patent Office: 522 Days
• Field of Search: 737/00, 737/54, 737/16
• US Class Current: 73/754
• CPC Class Codes: G01L 19/0609 Pressure pulsation damping arrangements
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm
• CPC Class Codes: G01L 9/125 with temperature compensating means non electric temperature compensating means G01L19/04

Abstract

A pressure sensing system formed in a monolithic semiconductor substrate. The pressure sensing system comprises a pressure sensing device formed on the monolithic semiconductor substrate. Pressure sensing device is adapted to be disposed in an environment for developing an electrical pressure signal corresponding to the pressure in the environment. The system includes driver circuitry formed in the monolithic semiconductor substrate. The driver circuitry is responsive to input electrical signal for generating an output pressure signal. A conductive interconnect structure formed in the monolithic semiconductor substrate to electrically connects the pressure sensing device to the driver circuitry such that electrical pressure signals developed by the pressure sensing device are provided as input electrical signals to the driver circuitry.

Claims

1. A pressure sensing system formed in a monolithic semiconductor substrate, the pressure sensing system comprising:

at least one enclosed cavity pressure sensing device formed on the monolithic semiconductor substrate, the at least one enclosed cavity pressure sensing device adapted to be disposed in an environment for developing an electrical pressure signal corresponding to the pressure in the environment;

at least one leaking cavity pressure device formed on the monolithic semiconductor substrate, the at least one leaking cavity pressure sensing device adapted to be disposed in the environment for developing a reference pressure signal;

differential circuitry formed in the monolithic semiconductor substrate and coupled to receive the electrical pressure signal from the enclosed cavity pressure sensing device and the reference pressure signal from the leaking cavity pressure sensing device and to generate an input electrical pressure signal;

driver circuitry formed in the monolithic semiconductor substrate, the driver circuitry being responsive to input electrical pressure signals for generating an output pressure signal; and

a conductive interconnect structure formed in the monolithic semiconductor substrate, the conductive interconnect structure being connected between the enclosed cavity pressure sensing device and the leaking cavity pressure sensing device and the differential circuitry and the driver circuitry.

2. A method of forming a pressure sensing system in a monolithic semiconductor substrate, the method comprising:

forming at least one enclosed cavity pressure sensing device in the monolithic semiconductor substrate, the enclosed cavity pressure sensing device adapted to be disposed in an environment for developing an electrical pressure signal corresponding to the pressure in the environment;

forming at least one leaking cavity pressure sensing device in the monolithic semiconductor substrate, the leaking cavity pressure sensing device adapted to be disposed in the environment for developing a reference pressure signal;

forming differential circuitry in the monolithic semiconductor substrate, the differential circuitry response to electrical pressure signals received from the enclosed cavity pressure sensing device and reference signals received from the leaking cavity pressure sensing device to generate input electrical pressure signals;

forming driver circuitry in the monolithic semiconductor substrate, the driver circuitry being responsive to input electrical signals for generating corresponding output pressure signal; and

forming a conductive interconnect structure in the monolithic semiconductor substrate, the conductive interconnect structure connecting the enclosed cavity pressure sensing device and the leaking cavity pressure sensing device and the differential circuitry and the driver circuitry.