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Title: Method for integrating microelectromechanical devices with electronic circuitry

Abstract

A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry on a common substrate. The MEM device can be fabricated within a substrate cavity and encapsulated with a sacrificial material. This allows the MEM device to be annealed and the substrate planarized prior to forming electronic circuitry on the substrate using a series of standard processing steps. After fabrication of the electronic circuitry, the electronic circuitry can be protected by a two-ply protection layer of titanium nitride (TiN) and tungsten (W) during an etch release process whereby the MEM device is released for operation by etching away a portion of a sacrificial material (e.g. silicon dioxide or a silicate glass) that encapsulates the MEM device. The etch release process is preferably performed using a mixture of hydrofluoric acid (HF) and hydrochloric acid (HCI) which reduces the time for releasing the MEM device compared to use of a buffered oxide etchant. After release of the MEM device, the TiN:W protection layer can be removed with a peroxide-based etchant without damaging the electronic circuitry.

Inventors:
 [1];  [2];  [2]
  1. Austin, TX
  2. Albuquerque, NM
Issue Date:
Research Org.:
Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
OSTI Identifier:
872569
Patent Number(s):
5963788
Assignee:
Sandia Corporation (Albuquerque, NM)
Patent Classifications (CPCs):
B - PERFORMING OPERATIONS B81 - MICROSTRUCTURAL TECHNOLOGY B81C - PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
G - PHYSICS G01 - MEASURING G01P - MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; integrating; microelectromechanical; devices; electronic; circuitry; disclosed; common; substrate; device; fabricated; cavity; encapsulated; sacrificial; material; allows; annealed; planarized; prior; forming; series; standard; processing; steps; fabrication; protected; two-ply; protection; layer; titanium; nitride; tungsten; etch; release; process; whereby; released; operation; etching; portion; silicon; dioxide; silicate; glass; encapsulates; preferably; performed; mixture; hydrofluoric; acid; hf; hydrochloric; hci; reduces; time; releasing; compared; buffered; oxide; etchant; removed; peroxide-based; damaging; sacrificial material; common substrate; microelectromechanical devices; process whereby; hydrofluoric acid; electronic circuit; hydrochloric acid; titanium nitride; electronic circuitry; processing steps; silicon dioxide; silicate glass; mechanical device; standard processing; processing step; preferably performed; forming electronic; integrating microelectromechanical; electromechanical devices; mechanical devices; microelectromechanical device; /438/148/

Citation Formats

Barron, Carole C, Fleming, James G, and Montague, Stephen. Method for integrating microelectromechanical devices with electronic circuitry. United States: N. p., 1999. Web.
Barron, Carole C, Fleming, James G, & Montague, Stephen. Method for integrating microelectromechanical devices with electronic circuitry. United States.
Barron, Carole C, Fleming, James G, and Montague, Stephen. Fri . "Method for integrating microelectromechanical devices with electronic circuitry". United States. https://www.osti.gov/servlets/purl/872569.
@article{osti_872569,
title = {Method for integrating microelectromechanical devices with electronic circuitry},
author = {Barron, Carole C and Fleming, James G and Montague, Stephen},
abstractNote = {A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry on a common substrate. The MEM device can be fabricated within a substrate cavity and encapsulated with a sacrificial material. This allows the MEM device to be annealed and the substrate planarized prior to forming electronic circuitry on the substrate using a series of standard processing steps. After fabrication of the electronic circuitry, the electronic circuitry can be protected by a two-ply protection layer of titanium nitride (TiN) and tungsten (W) during an etch release process whereby the MEM device is released for operation by etching away a portion of a sacrificial material (e.g. silicon dioxide or a silicate glass) that encapsulates the MEM device. The etch release process is preferably performed using a mixture of hydrofluoric acid (HF) and hydrochloric acid (HCI) which reduces the time for releasing the MEM device compared to use of a buffered oxide etchant. After release of the MEM device, the TiN:W protection layer can be removed with a peroxide-based etchant without damaging the electronic circuitry.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Jan 01 00:00:00 EST 1999},
month = {Fri Jan 01 00:00:00 EST 1999}
}

Works referenced in this record:

A surface micromachined silicon accelerometer with on-chip detection circuitry
journal, October 1994


Polysilicon integrated microsystems: technologies and applications
journal, August 1996


A smart accelerometer with on-chip electronics fabricated by a commercial CMOS process
journal, March 1992