Transcript 1.1 Silicon Crystal Structure

EE143
Microfabrication Technology
Professor:
Ali Javey
[email protected]
506 Cory Hall
(510) 643-7263
TAs:
SangHoon Lee, [email protected]
Peter Matheu, [email protected]
John Wyrwas, [email protected]
Web Page:
http://www-inst.eecs.berkeley.edu/~ee143/
EE143 – Ali Javey
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Schedule
• Lectures: Tue/Thu, 3:30pm-5pm
• Labs (218 Cory) – only 5 of the following 6 sections will be
offered:
–
–
–
–
–
M 2-5P, 218 CORY
Tu 10-1P, 218 CORY
W 9-12P, 218 CORY
Th 11-2P, 218 CORY
F 9-12P, 218 CORY
LAB SECTIONS WILL BEGIN ON January 28th
• Office Hours:
– Ali Javey (Cory Hall, 506)
Wednesdays, 10-11 am
– TAs (TBD)
EE143 – Ali Javey
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Reading Material
• Primary Text:
Introduction To Microelectronic Fabrication
R. C. Jaeger
Prentice Hall
• Reference Texts:
Semiconductor Device Fundamentals
R. F. Pierret
Addison Wesley
Device Electronics for Integrated Circuits
R. S. Muller and T. I. Kamins
Wiley
EE143 – Ali Javey
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Grading
– Laboratory
• Includes quizzes, lab work, and
reports
30%
– Homeworks
• Assigned on Thursdays, due the
following week in class
• You must work on your own
10%
– Tests (2-3)
• ~75 minutes each
• given periodically per schedule
• Open book and notes
• No makeups
30%
– Final Examination
• Friday, Dec. 15th, 12:30pm3:30pm
• Open book and notes
• No makeups
Letter grades will be assigned
based approximately on the
following scale:
A+: 95-100
A: 88-95
A-: 85-88
B+: 80-85
B: 73-80
B-: 68-73
C+: 65-68
C: 60-65
C-: 55-60
D: 40-55
F: <40
30%
EE143 – Ali Javey
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Course Information
• Prerequisites:
– EE40/E100 and Physics 7B or equivalent
• Course Description
– EE143 teaches the fundamentals of integrated-circuit (IC) fabrication
and surface-micromachining technology, giving the student a basic
understanding of IC and micromachining processes and the effect of
processing choices on device performance. Students learn to use
process simulation tools and also fabricate and characterize devices in
the laboratory. This lecture part will cover the processing techniques
and design methodologies of microfabrication. We will discuss the
process modules: lithography, thermal oxidation, diffusion, ion
implantation, etching, thin-film deposition, epitaxy, metallization. The
second part of the course will cover process simulation, layout design
rules, MOS, IC, and MEMS process integration. The laboratory part of
the course will provide students opportunities to have hands-on
experience to fabricate and characterize a NMOS chip with simple
MEMS components.
EE143 – Ali Javey
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Course Schedule
Introduction to Materials and Processing (1-2 weeks)
Photolithography (1 week)
Etching (1 week)
Oxidation (1 week)
Deposition (1 week)
Diffusion (1 week)
Ion Implantation (1 week)
Metallization/CMP (1 week)
Simulation/Layout (1 week)
Process Integration (1 week)
Introduction to Devices (2 weeks)
Nanolithography and Nanofabrication (1 week)
EE143 – Ali Javey
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Laboratory Information
•
We do our best to limit lab size to 12 people; as a result, your telebears
enrollment is not a guarantee of being assigned to a lab.
•
You MUST send an email to Professor Javey ([email protected]) by
Thursday 8pm including the following information:
– 1) Full Name
– 2) Major
– 3) Year (Jr., Sr., Grad student, etc.)
4) Rank list of preferred lab sections in descending order of preference (i.e., 1 st
choice, 2nd choice…)
– 5) List of any lab sections that you CANNOT attend
•
Failure to send an email may result in you being dropped from the course,
even if you are registered on telebears.
•
Final lab assignment will be sent to you via email. PLEASE ENSURE
THAT YOUR EMAIL ADDRESS ON TELEBEARS IS CORRECT,
SINCE THIS WILL BE USED FOR OFFICIAL CORRESPONDENCE!!!
EE143 – Ali Javey
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Lab Safety
Week of 1/28
• Mandatory Lab attendance required
• You will have a lab orientation session, and
will have to pass a safety quiz before you
are officially enrolled in this course.
• You MUST attend the lab session to which
you are assigned.
EE143 – Ali Javey
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Course Structure – Lab and Lecture
• You learn the theories in class; you practice them in
lab
• You are going to make:
– resistors, diodes, MOS-cap
– bipolar transistor, MOS-transistor, …
– some MEMS structures, like bimorphs, …
• By the end of the semester, you should have learnt
– basic lab techniques
– how to operate some fabrication equipment
– how to characterize the devices you made
EE143 – Ali Javey
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The EE143 Chip
EE143 – Ali Javey
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Lab Cleanliness
• only enter the clean room fully gowned
– hair net + lab coat + glove + shoe net + safety
goggles
•
do NOT touch chemicals / equipment with bare
hands
• always handle wafers with tweezers and trays
(unless told otherwise)
• wash hands before and after entering the lab
(why??)
– before: so as not to contaminate wafers or
equipment
– after: avoid chemicals being indigested
•
3rd week, GSIs will demonstrate how to clean
masks
• 4th week, GSIs will demonstrate how to piranhaclean wafers
EE143 – Ali Javey
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Lab Safety
• do NOT enter the lab when GSI aren’t present
• know all the emergency exits (ask the GSIs to
show you)
• know where to find the MSDS
– under the whiteboard in characterization room
•
•
•
•
•
know where to find the closet water sources,
shower, eye wash
ask whenever not clear
do NOT try things out without permission
NO eating, drinking, playing, etc. inside the lab
Things in the lab can be dangerous if not
carefully handled. Be sure to respect the
chemicals.
EE143 – Ali Javey
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Chemical Handling
• wear protective gear when handling corrosive chemicals
– face shield, chemical apron, chemical gloves, respirator if
necessary
•
•
•
•
check glove for holes
check pH of unknown spillage, label everything
corrosive chemicals: H2SO4, HF, aluminum etch, TMAH
wash and rinse the exposed body parts with water for >
15mins
• add acids to water, not the other way around
• handle wet chemicals only at sinks, acid on right, others on
left side
EE143 – Ali Javey
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Chemical Handling (cont’d)
• HF:
– be very very careful
– HF will penetrate your body and attack your skeletal
system; once you feel it, it is already eating your bones!!!
– apply calcium gluconate if exposure is suspected
– use only plastic beakers for HF (why??)
•
H2SO4:
–
–
–
–
very painful, severely burns
add H2O2 to H2SO4 to prepare piranha
do not carry the beaker around after mixing (HOT!!)
use only glass beakers for piranha (why??)
• Chemicals used in the lab are often harmful. Don’t
breathe and avoid exposure if possible.
• Use teflon-ware when handling wafers in acids. Be
careful, those teflon tweezers do not hold the wafers very
well!!
EE143 – Ali Javey
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Chemical Disposal
• organic chemicals are discarded in designated
containers
• NOTE: in this lab, photoresist (PR) is also
dumped down the drain.
• do NOT mix organic wastes with acids (why??)
– can cause fire or even explosion
• do NOT mix acids and bases
•
EE143 – Ali Javey
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Lab Floor Plan
Note: Not drawn to scale
W
hi
te
b
oa
rd
Left sink
(organic solvents)
Right sink
(acids)
Characterization
Lab
Furnace
Gas tanks
valves
flow meters
Clean Room
Station 3
Station 4
Microscope
with camera
Station 2
Shower
Eye-wash
Computer
Station 5
Ovens, hotplates
Station 1
Spinner
TA Station
Gowning Area
Evaporator
Mask aligner
Nanospec
Chemical
cabinets
4-point probes
Cory Hall Corridor
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EE143 Overview
• Microfabrication Principles for IC and MEMS
• Hands-on Fabrication and Testing of IC and MEMS Devices
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Fabricated Structures
• Using a series of planar processing steps, it is possible to
create sophisticated 3D electrical and mechanical structures.
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Electrical Functionality / Characterization
• The resulting structures may be characterization
electrically or mechanically
17-stage Ring Oscillator
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MEMS Actuators
Gear Speed Reduction Unit
Responsive Drug Delivery
Valve
EE143 – Ali Javey
Movable Mirror
Turbine engine
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Introduction to Si Processing
EE143 in one day
Silicon Device Fabrication Technology
Over 1019 transistors (or 1,000,000,000 for every
person in the world) are manufactured every year.
Variations of this versatile technology are used for
flat-panel displays, micro-electro-mechanical systems
(MEMS), and even DNA chips for DNA screening...
Terminology
SSI (Small Scale Integration) – few transistors
MSI (Medium Scale Integration) – hundreds
LSI (Large Scale Integration) - thousands
VLSI (Very Large Scale Integration) - millions
ULSI (Ultra Large Scale Integration)
Foundry (Fab)
• Foundry (also called a fab for fabrication
plant) is used to refer to a factory where
devices like integrated circuits are
manufactured. The central part of a fab is a
cleanroom.
• Note the difference between a fab and a lab.
Cleanroom Standards
Federal Standard Class Limits
MEASURED PARTICLE SIZE (MICROMETERS)
CLASS
0.1
0.2
0.3
0.5
5.0
1
35
7.5
3
1
NA
10
350
75
30
10
NA
100
NA
750
300
100
NA
1,000
NA
NA
NA
1,000
7
10,000
NA
NA
NA
10,000
70
100,000
NA
NA
NA
100,000
700
Why do we need cleanrooms?
Introduction to Device Fabrication
Oxidation
Lithography &
Etching
Ion Implantation
Annealing &
Diffusion
Deposition
Oxidation of Silicon
Dry Oxidation :
Wet Oxidation :
Si + O2  SiO2
Thin oxide
Si +2H2O  SiO2 + 2H2 Thick oxide
Oxidation of Silicon
Quartz tube
Si Wafers
Flow
controller
O2 N2
H 2O or TCE(trichloroethylene)
Resistance-heated furnace
Lithography
Development
Resist Coating
Positive resist
Negative resist
Photoresist
Oxide
Si
(a)
Deep Ultraviolet Light
Optical
Lens system
Si
Si
(c)
Photomask with
opaque and
clear patterns
Si
Si
(d)
Exposure
(b)
Etching and Resist Strip
Pattern Transfer–Etching
wet etch
Isotropic etching
dry etch
Anisotropic etching
photoresist
SiO 2
photoresist
SiO 2
(1)
(1)
photoresist
SiO 2
photoresist
SiO 2
(2)
SiO 2
(2)
SiO 2
(3)
(a) Isotropic wet etching
(3)
(b) Anisotropic dry etching.
Module: Ion Implantation
Ion Energy
~1 keV to
200 keV
EE143 – Ali Javey
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What is process integration?
• Sequential use of a series of simple process steps or
“modules” to create complex structures
Si wafer
Processing
Steps
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The EE143 Lab Process (part I)
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The EE143 Lab Process (Part II)
EE143 – Ali Javey
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