Title: Use of silicon oxynitride as a sacrificial material for microelectromechanical devices

Abstract

The use of silicon oxynitride (SiO.sub.x N.sub.y) as a sacrificial material for forming a microelectromechanical (MEM) device is disclosed. Whereas conventional sacrificial materials such as silicon dioxide and silicate glasses are compressively strained, the composition of silicon oxynitride can be selected to be either tensile-strained or substantially-stress-free. Thus, silicon oxynitride can be used in combination with conventional sacrificial materials to limit an accumulation of compressive stress in a MEM device; or alternately the MEM device can be formed entirely with silicon oxynitride. Advantages to be gained from the use of silicon oxynitride as a sacrificial material for a MEM device include the formation of polysilicon members that are substantially free from residual stress, thereby improving the reliability of the MEM device; an ability to form the MEM device with a higher degree of complexity and more layers of structural polysilicon than would be possible using conventional compressively-strained sacrificial materials; and improved manufacturability resulting from the elimination of wafer distortion that can arise from an excess of accumulated stress in conventional sacrificial materials. The present invention is useful for forming many different types of MEM devices including accelerometers, sensors, motors, switches, coded locks, and flow-control devices, with or without integrated electronicmore » circuitry. « less

Inventors:

Habermehl, Scott D ^[1]; Sniegowski, Jeffry J ^[2]

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1. Corrales, NM
2. Edgewood, NM

Issue Date:

Mon Jan 01 00:00:00 EST 2001

Research Org.:

Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)

OSTI Identifier:

873497

Patent Number(s):

6174820

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

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01L - SEMICONDUCTOR DEVICES

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B - PERFORMING OPERATIONS B81 - MICROSTRUCTURAL TECHNOLOGY B81C - PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS

B81C1/00666 - {Treatments for controlling internal stress or strain in MEMS structures}
B81C2201/0109 - Sacrificial layers not provided for in B81C2201/0107 - B81C2201/0108

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01L - SEMICONDUCTOR DEVICES

H01L21/0214 - {the material being a silicon oxynitride, e.g. SiON or SiON
H01L21/02164 - {the material being a silicon oxide, e.g. SiO2}
H01L21/02211 - {the compound being a silane, e.g. disilane, methylsilane or chlorosilane}
H01L21/02274 - {in the presence of a plasma [PECVD]}
H01L21/3144 - {on silicon}
H01L21/3145 - {formed by deposition from a gas or vapour}

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DOE Contract Number:  

AC04-94AL85000

Resource Type:

Patent

Country of Publication:

United States

Language:

English

Subject:

silicon; oxynitride; sacrificial; material; microelectromechanical; devices; sio; forming; device; disclosed; conventional; materials; dioxide; silicate; glasses; compressively; strained; composition; selected; tensile-strained; substantially-stress-free; combination; limit; accumulation; compressive; stress; alternately; formed; entirely; advantages; gained; formation; polysilicon; substantially; free; residual; improving; reliability; ability; form; degree; complexity; layers; structural; compressively-strained; improved; manufacturability; resulting; elimination; wafer; distortion; arise; excess; accumulated; useful; types; including; accelerometers; sensors; motors; switches; coded; locks; flow-control; integrated; electronic; circuitry; sacrificial material; microelectromechanical devices; electronic circuit; substantially free; control device; electronic circuitry; silicon dioxide; silicate glass; residual stress; devices including; compressive stress; silicon oxynitride; mechanical device; electromechanical devices; mechanical devices; microelectromechanical device; coded lock; /438/216/257/