Micro/Nanosystems Technology - Technische Fakultät · • Introduction - MEMS, NEMS, cleanroom and...

Micro/Nanosystems TechnologyWagner / Meyners 1

Micro/Nanosystems Technology

Prof. Dr. Bernhard Wagner

Dr. Dirk Meyners


Prof. Dr. Bernhard Wagner

Materials and Processes for Nanosystem Technologies

Fraunhofer-Institut für Siliziumtechnologie ISIT, Itzehoe

Tel: 04821-17-4213

[email protected]

Dr. Dirk Meyners Dr. Antonio Malavé

room: A – 212 room: A – 206

Tel. 880 6202 Tel. 880 6209

[email protected] [email protected]

Inorganic Functional Materials (Prof. Quandt)

Building A, 2nd floor (curr. 1st floor)




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.)



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)


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.



Image source: M. Madou,

Fundamentals of Micro-

fabrication, 2002

Various Objects

and their sizes


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



• 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 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



Outline

• Introduction

• Literature

• The origin of microsystems technology

• Sensors, actuators, microcomponents

• Nanomachining and Nanochemistry

• Cleanroom and vacuum technology

• Cleanroom technology



Outline

• Introduction

• Literature







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




Outline

• Introduction

• Literature







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.



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:



Types of transistors:

– Bipolar Junction Transistor (BJT)

– Metal Oxide Semiconductor (MOS) transistor

MOS transistor

metal

oxide

semiconductor



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.



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



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.



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



Outline

• Introduction

• Literature







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.


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



Outline

• Introduction

• Literature







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.



An important tool for manipulating single atoms is the Scanning

Tunneling Microscope.



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



Outline

• Introduction

• Literature






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



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



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.



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



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%



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



• 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



• 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.



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.


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



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



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



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



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).



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:


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


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.

Micro/Nanosystems Technology - Technische Fakultät · • Introduction - MEMS, NEMS, cleanroom and...

Documents

Transcript of Micro/Nanosystems Technology - Technische Fakultät · • Introduction - MEMS, NEMS, cleanroom and...