Post on 25-May-2020
Micro/Nanosystems TechnologyWagner / Meyners 1
Micro/Nanosystems Technology
Prof. Dr. Bernhard Wagner
Dr. Dirk Meyners
Micro/Nanosystems TechnologyWagner / Meyners 2
Prof. Dr. Bernhard Wagner
Materials and Processes for Nanosystem Technologies
Fraunhofer-Institut für Siliziumtechnologie ISIT, Itzehoe
Tel: 04821-17-4213
bernhard.wagner@isit.fraunhofer.de
Dr. Dirk Meyners Dr. Antonio Malavé
room: A – 212 room: A – 206
Tel. 880 6202 Tel. 880 6209
dm@tf.uni-kiel.de ama@tf.uni-kiel.de
Inorganic Functional Materials (Prof. Quandt)
Building A, 2nd floor (curr. 1st floor)
Micro/Nanosystems Technology
Micro/Nanosystems TechnologyWagner / Meyners 3
Micro/Nanosystems Technology
mawi-904
Lecture:
Micro/Nanosystems Technology (MicSysTec) (080309)
Tue: 8:15 – 10:45 and Fr: 11:15 – 12:45
Exercises / lab course:
Micro/Nanosystems Technology – Exercises
four times per semester, on Tue: 8:00 – 13:00, 14:00 – 18:00
In WS19/20 four lab courses will take place (in the cleanroom).
This course will cover the topics discussed in the prior lectures.
Number of students is limited to 16
Written examination at the end of the semester (Participation in the
exercises / lab courses is mandatory.)
Micro/Nanosystems TechnologyWagner / Meyners 4
Micro/Nanosystems Technology
etit-521
Lecture:
Micro/Nanosystems Technologies Exercise (MicSysTec)
Tue: 8:15 – 11:45 and Fr: 11:15 – 12:45
Exercises
Microsystem Technologies Exercise (080313)
Not provided in WS19/20 ???
Oral examination at the end of the semester
(register for the exam in the office of the Institute of Electrical and
Information Engineering)
etit-521 is also classified as mawi-module!
contact person: Simon Fichtner (phone: 6197)
Micro/Nanosystems TechnologyWagner / Meyners 5
Microsystems Technology (MST, Europe)
[also: Micromachining, microfabrication or micro electromechanical
systems (MEMS, USA)] refers to the fabrication of devices with at least
some of their dimensions in the micrometer range.
Nanosystems Technology (NST)
[also: Nanomachining or nano electromechanical systems (NEMS)]
extends microsystems technology into the submicron range.
Micro/Nanosystems TechnologyWagner / Meyners 6
Micro/Nanosystems Technology
Image source: M. Madou,
Fundamentals of Micro-
fabrication, 2002
Various Objects
and their sizes
Micro/Nanosystems TechnologyWagner / Meyners 7
Why miniaturization?
• Minimizing energy and materials use in manufacturing
• Faster devices
• Integration with electronics
• Redundancy and arrays
• Reduction of power budget
• Surface effects become dominant, bulk effects are reduced
• Increased selectivity and sensitivity
• Wider dynamic range
• Exploitation of new effects through the breakdown of continuum
theory in the micro- and nanodomain
Micro/Nanosystems TechnologyWagner / Meyners 8
Micro/Nanosystems Technology
• Introduction
- MEMS, NEMS, cleanroom and vacuum technology
- Wafer substrate materials
• Thin film deposition techniques
- Magnetron sputtering, evaporation techniques, Pulsed Laser Deposition
- Chemical Vapor Deposition
• Lithography
- UV-Lithography, Electron Beam Lithography, Patterning with Focused Ion
Beam, Resolution Enhancement
• Silicon Doping, Materials
• Pattern transfer with Dry/Wet Etching Techniques
• Surface Micromachining
• Electroplating
• Wafer Bonding
• Piezoresistive, Piezoelectric and Capacitive Sensors
• Pressure and Inertial Sensors
• MOEMS (Micro-Opto-Electro-Mechanical Systems)
• Thermal Sensors
Course Outline
Micro/Nanosystems TechnologyWagner / Meyners 9
Micro/Nanosystems Technologyschedule (minor changes are possible)
WS 19/20 Topics Lecture /
Labcourse
Tue. 22.10. Introduction lec. / dm
Fr. 25.10. Introduction lec. / dm
Tue. 29.10 Cleanroom and Vacuum
Technology
lec. / dm
Fr. 01.11 Physical Vapor Deposition (PVD) lec. / dm
Tue. 05.11 Cleanroom Technology lab. / dm
Fr. 08.11. Wafer Substrate Materials lec. / bw
Tue. 12.11. PVD & Chemical Vapor Deposition
(CVD)
lec. / dm
Fr. 15.11. Chemical Vapor Deposition (CVD) lec. / dm
Tue. 19.11. UV-Lithography lec. / dm
Fr. 22.11. Silicon doping lec. / bw
Tue. 26.11. Lithography lab. / dm
Fr. 29.11. Materials I lec. / bw
Tue. 03.12. Materials II lec. / bw
WS 19/20 Topics Lecture /
Labcourse
Fr. 06.12. Wet etching lec. / bw
Tue. 10.12. Dry Etching
Presentation of UV litho
results (students)
lec. / dm
Fr. 13.12. Dry etching & Resolution
Enhancement Techniques
lec. / dm
Tue. 17.12. Dry Etching lab. / dm
Christmas break
Tue. 07.01. Surface Micromachining
+ Capacitive Sensors
lec. / bw
Fr. 10.01. Piezoresistive Sensors lec. / bw
Tue. 14.01. Electron & Focused Ion
Beam Lithography
Presentation of dry etching
results (students)
lec. / dm
Fr. 17.01. Pressure Sensors lec. / bw
Tue. 21.01. Electroplating of Sn lab. / bw
Fr. 24.01. Inertial Sensors lec. / bw
Tue. 28.01. MOEMS lec. / bw
Fr. 31.01. Thermal Sensors + exam
topics & hints
lec. / bw
Micro/Nanosystems TechnologyWagner / Meyners 10
Micro/Nanosystems Technology
Outline
• Introduction
• Literature
• The origin of microsystems technology
• Sensors, actuators, microcomponents
• Nanomachining and Nanochemistry
• Cleanroom and vacuum technology
• Cleanroom technology
Micro/Nanosystems TechnologyWagner / Meyners 11
Micro/Nanosystems Technology
Outline
• Introduction
• Literature
• The origin of microsystems technology
• Sensors, actuators, microcomponents
• Nanomachining and Nanochemistry
• Cleanroom and vacuum technology
• Cleanroom technology
Micro/Nanosystems TechnologyWagner / Meyners 12
Literature:
Marc J. Madou, Fundamentals of microfabrication: the science of
miniaturization, CRC Press, 2002
W. Menz, J. Mohr, O. Paul, Microsystems Technology, WILEY-VCH, 2001
(Mikrosystemtechnik für Ingenieure, WILEY-VCH, 2005)
M. A. McCord, M. J. Rooks, in Handbook of Microlithography,
Micromachining and Microfabrication – Vol 1, SPIE Optical Engineering
Press, 1997
D. K. Stewart, j. D. Casey, in Handbook of Microlithography, Micromachining
and Microfabrication – Vol 2, SPIE Optical Engineering
Press, 1997
Chang Liu, Foundations of MEMS, Pearson Education, New Jersey, 2006
Sergey E. Lyshevski, MEMS and NEMS: Systems, Devices, and Structures,
CRC Press, 2002
Micro/Nanosystems Technology
Micro/Nanosystems TechnologyWagner / Meyners 13
Micro/Nanosystems Technology
Outline
• Introduction
• Literature
• The origin of microsystems technology
• Sensors, actuators, microcomponents
• Nanomachining and Nanochemistry
• Cleanroom and vacuum technology
• Cleanroom technology
Micro/Nanosystems TechnologyWagner / Meyners 14
The origin of Microsystems Technology
Microsystems technology is based on the immense sum of experience
developed by microelectronic engineers and physicists in the recent
decades.
John Bardeen, Walter Brattain
and William Shockley invented
the first transistor in 1948.
The transistor demonstrated for
the first time that amplification in
solids was possible (in contrast to
tube).
In 1956 the team received the
Nobel Prize in physics for their
efforts.
Micro/Nanosystems TechnologyWagner / Meyners 15
The origin of Microsystems Technology
The three elements of the
transistor are
(1) the EMITTER, which gives off, or emits," current carriers (electrons or holes);
(2) the BASE, which controls the flow of current carriers; and
(3) the COLLECTOR, which collects the current carriers.
There are many different types of transistors, but the basic theory
of their operation is all the same:
Micro/Nanosystems TechnologyWagner / Meyners 16
The origin of Microsystems Technology
Types of transistors:
– Bipolar Junction Transistor (BJT)
– Metal Oxide Semiconductor (MOS) transistor
MOS transistor
metal
oxide
semiconductor
Micro/Nanosystems TechnologyWagner / Meyners 17
The origin of Microsystems Technology
In the 1950s the first integrated circuit (IC) was developed in the
1950s by Jack Kilby at Texas Instruments and Robert Noyce at
Fairchild Semiconductor.
A chip or an integrated circuit is a small electronic device made out
of a semiconductor material.
The integrated circuit consists of elements (transistors, diodes, etc.)
inseparably associated and formed on or within a single substrate.
The circuit components and all interconnections are formed as a unit.
Integrated circuits can be classified by the number of transistors
and other electronic components they contain.
Micro/Nanosystems TechnologyWagner / Meyners 18
The origin of Microsystems Technology
Scale of integration Electronic components per
chip
SSI (small-scale
integration):
<= 100
MSI (medium-scale
integration):
100 to 3,000
LSI (large-scale integration): 3,000 to 100,000
VLSI (very large-scale
integration
100,000 to 107
ULSI (ultra large-scale
integration
107 to 109
GSI (giga scale integration) > 109
Micro/Nanosystems TechnologyWagner / Meyners 19
The origin of Microsystems Technology
Microsystems technology, in a narrow sense, comprises the use of a
set of manufacturing tools based on techniques commonly used in the
integrated circuit industry or IC industry.
This involved originally mainly Si based mechanical devices such as
pressure sensors, accelerometers and gyroscopes.
In the 1990s the application of MST broadened and new techniques
such as micromolding, laser machining, electron – and ion beam
machining entered the field of miniaturization. Also, new materials such
as gas-permeable membranes, biological cells, enzymes and antibodies
were introduced.
This opened the application of MEMS to biological, medical and chemical
or information/communication-related problems.
Micro/Nanosystems TechnologyWagner / Meyners 20
The origin of Microsystems Technology
As a consequence, today, the term MEMS refers to all miniaturized
systems including Si-based mechanical devices, chemical and
biological sensors and actuators, and miniature non-silicon structures
(e.g. made from plastics or ceramics). The most important are:
Mechanical MEMS pressure sensors,
accelerometers, gyros
BIOMEMS microfluidic structures, drug
delivery devices, DNA
arrays
MOEMS micromirror arrays, lenses,
gratings
Radio Frequency MEMS inductors, capacitors,
antennas
HARMEMS high-aspect-ratio MEMS
Micro/Nanosystems TechnologyWagner / Meyners 21
Micro/Nanosystems Technology
Outline
• Introduction
• Literature
• The origin of microsystems technology
• Sensors, actuators, microcomponents
• Nanomachining and Nanochemistry
• Cleanroom and vacuum technology
• Cleanroom technology
Micro/Nanosystems TechnologyWagner / Meyners 22
Sensors, actuators, microcomponents
Sensor element: A sensor element is a device that converts one form of
energy into another (e.g. piezoelectric material that converts
mechanical energy into electricity). Its function is to provide a user with
a “usable energy output” in response to a specific measurable input.
Sensor: A sensor includes a sensor element or an array of sensor
elements with physical packaging and external electrical or optical
connections.
Sensor System: A sensor system includes the sensor and its digital or
analog signal processing hardware.
Micro/Nanosystems TechnologyWagner / Meyners 23
Sensors, actuators, microcomponents
Actuator: An actuator is a device that converts energy from one form to
another similarly to sensors. But actuators are components that convert
energy into an appropriate action (e.g. opening a valve, positioning a
mirror, pumping liquids).
Microcomponents: A microcomponent (or microstructure) refers to a
part that has at least one of its dimensions in the micrometer range but
is not a sensor, actuator or microsystem. Examples are single micro
lenses, micro mirrors, needles etc.
Microsystem: A device with at least one of its dimensions in the
micrometer range
Micro/Nanosystems TechnologyWagner / Meyners 24
Micro/Nanosystems Technology
Outline
• Introduction
• Literature
• The origin of microsystems technology
• Sensors, actuators, microcomponents
• Nanomachining and Nanochemistry
• Cleanroom and vacuum technology
• Cleanroom technology
Micro/Nanosystems TechnologyWagner / Meyners 25
Nanomachining and Nanochemistry
Nanomachining or NEMS is the top-down approach to devices with
lateral dimensions in the nanometer range. Starting from larger blocks
smaller and smaller items are fabricated.
Nature works the other way, i.e., from the bottom-up. All living things
are made atom by atom , molecule by molecule; from the small to the
large.
This bottom-up approach is adopted from nanochemistry (Marc
Madou). Nanochemistry uses reversible interactions to assemble small
molecules (or atoms) into nanosized, supramolecular patterns.
Micro/Nanosystems TechnologyWagner / Meyners 26
Nanomachining and Nanochemistry
An important tool for manipulating single atoms is the Scanning
Tunneling Microscope.
Micro/Nanosystems TechnologyWagner / Meyners 27
Nanomachining and Nanochemistry
It is also possible to attach sample atoms to the tip and drop them on
another place.
To attain higher building speed, other methods such as self-assembly
or the use of larger building blocks (clusters) are essential.
Photo source: IBM's Almaden Research Labs
Xenon atoms on nickel surface
Micro/Nanosystems TechnologyWagner / Meyners 28
Micro/Nanosystems Technology
Outline
• Introduction
• Literature
• The origin of microsystems technology
• Sensors, actuators, microcomponents
• Nanomachining and Nanochemistry
• Cleanroom and vacuum technology
• Cleanroom technology
Wagner / Meyners 29Micro/Nanosystems Technology
Why working in a cleanroom?
A typical process flow in MST
contaminated substrate cleaning / stripping mask
from last cycle
film deposition
lithography
pattern transferseparated microstructures
typ
ica
lly 5
to
40
cycle
s
Wagner / Meyners 30Micro/Nanosystems Technology
Why working in a cleanroom?
Image source: Sandia National Labs
Typical feature size 1 to 100 µm
Final product of MST:
Image source: materials.usask.ca/photos/
Final product of microelectronics:
data source: International Roadmap
for Semiconductors (ITRS) from
1999, 2003 and 2016
Year DRAM half pitch
1999 180 nm
2006 70 nm
2009 50nm
2012 32 nm
2015 24 nm
Wagner / Meyners 31Micro/Nanosystems Technology
Why working in a cleanroom?
Image source: materials.usask.ca/photos/
Final product of microelectronics:
Year DRAM half pitch
1999 180 nm
2006 70 nm
2009 50nm
2012 32 nm
2015 24 nm
Transistor:
Metal 1 pitchMetal 1 half pitch
Minimum printable feature size
(critical dimension: CD) is even smaller.
Here CD corresponds to Gate length.
Wagner / Meyners 32Micro/Nanosystems Technology
Why working in a cleanroom?
Dust particles have diameters in the micrometer range >> minimum feature size!
Possible defects: shortcuts (a) or broken interconnections/devices (b)
(a)
(b)
Contamination with particles has to be avoided.
Processing in cleanrooms and vacuum systems is required.
pattern transfer
cleaning
Wagner / Meyners 33Micro/Nanosystems Technology
Why working in a cleanroom?
Defect-Yield Correlation
• n process steps are needed for chip fabrication
• the chip works only when all steps succeed
• step i succeeds with yield Yi
• the total yield ( # working chips / # chips on a wafer) is then:
n
i
iYY1
number of
steps
Yi = 90% Yi = 99% Yi = 99.9%
20 12% 82% 98%
40 1.5% 67% 96%
80 0.02% 44% 92%
Wagner / Meyners 34Micro/Nanosystems Technology
Why working in a cleanroom?
An example:
• chip with n transistors (no redundancy)
• a transistor is broken with error probability
Probability to find a working transistor:
Yield of working chips:
• z average number of errors in a chip
• II.) I.) :
nTC
TT
T
YY
YY
Y
1
1
n
zYT
I.)
II.)
zn
n
C en
zY
1
z
C eY
chip
transistor
Wagner / Meyners 35Micro/Nanosystems Technology
Why working in a cleanroom?
• average number of broken transistors in a chip z = 1
Despite the facts, that there is no redundancy and that the number of
broken transistors per chip averages out to z = 1, the probability to find
a working chip is still 37%.
37.01 eYC
Wagner / Meyners 36Micro/Nanosystems Technology
Why working in a cleanroom?
• D denotes the (constant) density of fabrication errors on a wafer
• AC denotes the chip area
• Then the yield can be calculated by:
the larger the chip area the lower the yield.
• Usually several fabrication steps are necessary to build a chip:
CDAz
C eeY
m
i
Ci
m
ADzzz
C eeeeY 121
m: number of fabrication steps
Di: error density for step i
CmDA
C eY
Di = D = const.
Wagner / Meyners 37Micro/Nanosystems Technology
Why working in a cleanroom?
stepsn fabricatio ofnumber :m ;CmDAz
C eeY
m=10
m=20
CDAz
Image source: W. Menz, Mikrosystemtechnik für Ingenieure, 2005
An excellent control of each fabrication step is needed for achieving an
acceptable yield. This motivates the use of cleanrooms and vacuum technology.
Wagner / Meyners 38Micro/Nanosystems Technology
Cleanroom technology
Functions of a cleanroom:
• lowering particle contamination of air
• control room temperature
• control air humidity
• control air pressure
• provide special illumination of rooms with light-sensitive chemicals
(lithography)
• provide sterility in case of medical applications
Wagner / Meyners 39Micro/Nanosystems Technology
Cleanroom technology
Cleanrooms are classified according to particle concentration in air.
US Federal Standard 209 D
• considers the density of particles with diameter >= 0.5µm
cleanroom
class
particle density (particles/ft3) of particles with diameter
>= 0.1µm >= 0.2µm >= 0.3µm >= 0.5µm >= 5µm
1 35 7 3 1 not defined
10 350 75 30 10 not defined
100 not defined 750 300 100 not defined
1 000 not defined not defined not defined 1 000 7
10 000 not defined not defined not defined 10 000 70
Wagner / Meyners 40Micro/Nanosystems Technology
Cleanroom technology
New metric standard ISO 14644
• considers the density of particles with diameter >= 0.1µm
cleanroom
class
particle density (particles/m3) of particles with diameter
>= 0.1µm >= 0.2µm >= 0.3µm >= 0.5µm >= 1µm >= 5µm
ISO Class 1 10 2
ISO Class 2 100 24 10 4
ISO Class 3 1 000 237 102 35 8
ISO Class 4 10 000 2 370 1 020 352 83
ISO Class 5 100 000 23 700 10 200 3 520 832 29
ISO Class 6 1 000 000 237 000 102 000 35 200 8 320 293
ISO Class 7 not
defined
not
defined
not
defined
352 000 83 200 2 930
Wagner / Meyners 41Micro/Nanosystems Technology
Cleanroom technology
In a cleanroom with ISO Class n not more than 10n particles with
diameters larger than 0.1µm are counted per m3.
Correlation between the two standards:
ISO 14644 FS 209 D
ISO Class 1 Class 0.01
ISO Class 2 Class 0.1
ISO Class 3 Class 1
ISO Class 4 Class 10
ISO Class 5 Class 100
ISO Class 6 Class 1 000
ISO Class 7 Class 10 000
Kiel’s Nanolab
microelectronic
production
Wagner / Meyners 42Micro/Nanosystems Technology
Cleanroom technology
particle diameter [µm]
pa
rtic
le d
en
sity n
[m
3]
particle density in
air of major city
Kiel’s Nanolab
The particle density in a normal environment is 10 000 higher than in the cleanroom
of the Nanolab (and 107 higher than in a microelectronics production lab).
Wagner / Meyners 43Micro/Nanosystems Technology
Cleanroom technology
Counting particles:
• a pump intakes air with constant
pumping speed; the air is channeled into
a measuring chamber
• a laser diode illuminates the chamber
• a photo diode measures the scattered
light intensity
• pulse frequency and light intensity
provide information about particle
number and particle diameter
Particle counter:
Wagner / Meyners 44Micro/Nanosystems Technology
Summary and Outlook
• We have answered the question, “Why miniaturization?”
• Origin of Microsystems Technology
• Introduction of terms which are necessary for talking about MEMS and
NEMS
• Cleanroom technology
Download of presentations and handouts:
http://www.tf.uni-kiel.de/matwis/afm/en/teaching
login: student password: tf-afm-2009
Next Time:
• Cleanroom technology, Kiel’s Nanolab
• Vacuum technology
The first lab course will take place on Tuesday, the 5th of November.