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MEMS Calculator
developed
at the National Institute of Standards and Technology for
use with ASTM and SEMI standards |
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This MEMS
Calculator determines the following thin
film properties from data taken with an optical
interferometer or comparable instrument: a) residual strain from fixed-fixed beams, b)
strain gradient from cantilevers, c) step heights or
thicknesses from step-height test structures, and d)
in-plane lengths or deflections. An optical vibrometer
or comparable instrument is used to obtain Young's modulus from resonating
cantilevers or fixed-fixed beams, and a material test machine is used to obtain
the wafer bond strength from micro-chevron test structures. |
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To help navigate through this web page, the
symbol  denotes items applicable to the MNT
5-in-1 Standard Reference Material (SRM); however, the pertinent
data sheets should be considered generic.
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For the MEMS Calculator, the following material is
available:
1)
User Guides:
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a) |
UsersGuide.SRM.pdf |
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This User's
Guide provides helpful
information pertaining to the MNT 5-in-1 SRM. Click here
for additional information. |
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b) |
UsersGuide.YM.r1.pdf |
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This User's
Guide (revision 1) provides helpful information pertaining to the 2008-2009
SEMI MEMS Young's Modulus and Step Height Round Robin Experiment. |
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c) |
UsersGuide.L&S.pdf |
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This User's
Guide was used during the 2002 ASTM MEMS Length and Strain
Round Robin Experiment and provides helpful information
pertaining to residual strain, strain gradient, and in-plane
length measurements. |
2)
Parameters under consideration and the data sheets used for on-line
calculations (with the recommended usage of Internet Explorer):
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a) |
Young's
modulus (using SEMI standard MS4) |
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i) |
Data Sheet YM.1-
To find
Young's modulus using single layered resonating cantilevers (or fixed-fixed
beams) |
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b) |
Residual
strain (using ASTM standard E 2245) |
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i) |
Data Sheet RS.1-
To find residual strain using fixed-fixed beam test structures |
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ii) |
Data Sheet RS.2 - To find residual
strain using
fixed-fixed beam test structures with a more detailed
calculation of the combined standard uncertainty, uc
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c) |
Strain
gradient (using ASTM standard E 2246) |
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i) |
Data Sheet SG.1-
To find strain gradient using cantilever test structures |
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ii) |
Data Sheet SG.2 - To find strain
gradient using
cantilever test structures with a more detailed calculation
of uc
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d) |
Step height (using SEMI standard MS2) |
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i) |
Data Sheet SH.1-
To find step heights from one step height test structure |
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ii) |
Data Sheet SH.2 - To find step
heights taken during the same data session from
two step height test structures |
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iii) |
Data Sheet SH.3 - To find step
heights taken during different data sessions from two
step height test structures |
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e) |
Thickness (using SEMI standard MS2) |
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i) |
Data Sheet T.1 -
To find the oxide thickness in a commercial CMOS process |
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ii) |
Data Sheet T.2 - To find the
thicknesses
of all the layers in a CMOS process using electro-physical
technique |
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iii) |
Data Sheet T.3 - To find thicknesses in MEMS processes using optomechanical
technique. |
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f) |
In-plane
length or Deflection (using ASTM standard E 2244) |
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i) |
Data Sheet L.1-
To find in-plane lengths with two ends anchored (or to find
an inside edge-to-inside edge length measurement) |
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ii) |
Data Sheet L.2 -
To find in-plane lengths with transitional edges oriented in
the same direction (or to find an inside edge-to-outside
edge length measurement from one data trace) |
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iii) |
Data Sheet L.3 -
To find in-plane lengths with one end anchored (or to
find an inside edge-to-outside edge length measurement from
two data traces) |
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iv) |
Data Sheet L.4 -
To find in-plane lengths with two ends unanchored (or
to find an outside edge-to-outside edge length measurement) |
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v) |
Data Sheet L.5 -
To find in-plane deflections from released part to released
part |
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vi) |
Data Sheet L.6 -
To find in-plane deflections from released part to fixed
location |
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g) |
Wafer bond
strength (using SEMI standard MS5) |
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i) |
Data Sheet WBS.1 - To find wafer bond
strength using
micro-chevron test structures |
3)
The MNT 5-in-1 SRMs:
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a) |
SRM number and description: |
Status |
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SRM 2494: MNT 5-in-1 test chip
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Using CMOS/MEMS process at
On
Semiconductor through MOSIS |
currently not available |
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SRM 2495: MNT 5-in-1 test chip
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Using PolyMUMPs process at
MEMSCAP |
currently not available |
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SRM 2496: MNT 5-in-1 test chip
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Using CMOS CMP process at
Taiwan's VIS facility through ITRI |
currently not available |
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b) |
Contact information to order an MNT
5-in-1 SRM: |
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mailing
address:
Standard Reference Materials Program
NIST,
100 Bureau Drive, Stop 2300
Gaithersburg, MD 20899-2300 |
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phone:
301-975-6776 or 301-975-2200 |
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fax: 301-948-3730 |
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email:
srminfo@nist.gov |
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URL:
http://ts.nist.gov/measurementservices/referencematerials/index.cfm |
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c) |
Technical contact: mems-support@nist.gov |
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4) Design files and accompanying
tiff files:
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The following design file (in
GDS-II format), as shown in the accompanying tiff file, was used to fabricate
the prototype MNT 5-in-1 SRMs: |
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a) |
5n1CMOSthick.gds
5n1CMOSthick.tif |
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This design file
(in GDS-II format) and corresponding tiff file are for chips fabricated on the 1.5 mm
On Semiconductor CMOS ABN
process available through MOSIS.
Visit
MOSIS
(http://www.mosis.com) for
fabrication specifics. |
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The following design file (in GDS-II
format), as shown in the accompanying tiff file, was used to fabricate
the 2008-2009 MEMS Young's Modulus and Step Height Round Robin
Experiment Test Chips: |
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b) |
RR.CMOS.gds
RR.CMOS.tif |
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This design file
(in GDS-II format) and corresponding tiff file are for chips fabricated on the 1.5 mm
On Semiconductor CMOS ABN
process available through MOSIS.
Visit
MOSIS
(http://www.mosis.com) for
fabrication specifics. |
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The following two design files (in
GDS-II format), as shown in the accompanying tiff files,
may be used for instructional purposes in conjunction with
Data Sheets RS, SG, and L and the MUMPs design file was used to fabricate the 2002 ASTM MEMS Length and Strain
Round Robin Experiment Test Chips: |
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c) |
mumps46.gds
mumps46.tif |
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This design file
(in GDS-II format) and corresponding tiff file are for chips fabricated on the MUMPs46.
Visit
MEMSCAP
(http://www.memscap.com) for fabrication specifics. |
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d) |
music1.gds
music1.tif |
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This design file
(in GDS-II format) and corresponding tiff file are for chips fabricated on the second surface-micromachining MUSiC
processing run. |
5)
List of pertinent SEMI standard test
methods:
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Consult the following
three SEMI standards for
details concerning the
inputs
to Data Sheets YM, SH, T,
and WBS: |
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a)
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SEMI MS2, Test Method
for Step Height
Measurements of Thin Films.
Click here
for ordering
information.
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b)
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SEMI MS4, Test Method
for Young's Modulus
Measurements of Thin,
Reflecting Films Based
on the Frequency of
Beams in Resonance.
Click here
for ordering
information.
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c)
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SEMI MS5, Test Method
for Wafer Bond Strength
Measurements Using
Micro-Chevron Test
Structures.
Click here
for ordering
information.
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6)
List of pertinent ASTM standard test methods:
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Consult the following three ASTM
standards for details concerning the inputs to Data Sheets
L, RS, and SG, respectively: |
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a) |
ASTM E 2244,
Standard Test Method for In-Plane Length Measurements of
Thin, Reflecting Films Using an Optical Interferometer.Click
here
for ordering
information. |
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b) |
ASTM E 2245,
Standard Test Method for Residual Strain Measurements of
Thin, Reflecting Films Using an Optical Interferometer.Click
here
for ordering
information. |
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c) |
ASTM E 2246,
Standard Test Method for Strain Gradient Measurements of
Thin, Reflecting Films Using an Optical Interferometer.Click
here
for ordering
information. |
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These standards are also available
in the
Annual Book of ASTM Standards,
Vol. 03.01.
Click here
for ordering information. |
7) List of MEMS terminology
standards:
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a) |
ASTM E 2444,
Terminology Relating to Measurements Taken on Thin,
Reflecting Films.
Click here
for ordering
information. This
standard is also available in the
Annual Book of ASTM Standards,
Vol. 03.01.
Click here
for ordering information. |
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b) |
SEMI MS3,
Terminology for MEMS Technology.
Click here
for ordering
information. |
8) List of other pertinent
references:
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Reference Link |
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Brief Description |
Pertinent Parameter(s) |
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a) |
EDL.vol.28.11.07.pdf |
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This Electron Device Letter presents a
method of obtaining the Young's modulus values of all the
layers in a CMOS process. The thicknesses obtained
from the electro-physical technique are amongst the inputs
for the optimization program. |
Young's modulus & thickness |
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b) |
NISTJRes.V112.No5.07.pdf |
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This NIST Journal of Research article
presents the electro-physical technique used to obtain all
the thicknesses in a CMOS process using Data Sheet T.2.
It also provides the user with a more in-depth understanding
of SEMI standard MS2. |
step height & thickness |
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c) |
JMEMS.Thick.2001 |
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This JMEMS article presents an
optomechanical technique for measuring layer thickness in
MEMS processes. Data Sheet T.3 can be used for the
calculations. |
thickness |
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d) |
NISTSP1048.pdf |
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This 2006 NIST Special Publication
(NISTSP 1048) lists (on page 309) the US Measurement System
(USMS) critical measurement targets for accelerating
innovation in Micro Nano Technology. |
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e) |
NISTIR7291.pdf |
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This NIST Internal Report (NISTIR
#7291) presents the 2002 ASTM MEMS Length and Strain Round
Robin Results and the uncertainty equations used in Data
Sheets RS, SG, and L. |
residual strain, strain gradient, &
length |
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f) |
NISTIR6779.pdf |
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This NIST
Internal Report (NISTIR #6779) provides the user with a
more in-depth understanding of the ASTM standard test
methods used in Data Sheets RS, SG, and L. |
residual strain, strain gradient, &
length |
Email questions or comments to mems-support@nist.gov.
Adobe Acrobat Reader (version 4.0x or
greater) will be needed to view many of these documents. If you do
not have this program, you may
download
it free of charge. The software is identified in order to assist
users of this information service. In no case does such
identification imply recommendation or endorsement by the National
Institute of Standards and Technology.
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