Method for integrating microelectromechanical devices with electronic circuitry

Patent · Fri Jan 01 00:00:00 EST 1999

OSTI ID:872569

Barron, Carole C ^[1]; Fleming, James G ^[2]; Montague, Stephen ^[2]

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1. Austin, TX
2. Albuquerque, NM

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.

• Research Organization: Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
• DOE Contract Number: AC04-94AL85000
• Assignee: Sandia Corporation (Albuquerque, NM)
• Patent Number(s): US 5963788
• OSTI ID: 872569
• Country of Publication: United States
• Language: English

Related Subjects

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/