Application of ANSI/ESD S20.20 to
Semiconductor Manufacturing
Carl Newberg
River’s Edge Technical Service, Inc.
www.retsinc.com
Acknowledgements
We would like to acknowledge Patrick Lim of
3M for many of the drawings used in this
presentation.
Many thanks to Patrick and 3M for their
willingness to allow the use of their
drawings.
What Is ANSI/ESD S20.20?
l ANSI/ESD
S20.20 defines a companies
ESD control program
l Can be equated with (and actually is
becoming a part of) ISO 9000 quality
programs
l Applies to areas handling devices down to
100 volts (HBM).
ANSI/ESD S20.20
Applying ANSI/ESD S20.20 to semiconductor
manufacturers
l Equipment
Manufacturers
l Semiconductor
Manufacturers/Processors
ANSI/ESD S20.20
Equipment Manufacturers
l Program ensures that
equipment is manufactured in a high quality
ESD controlled environment
l Protects Customers from
equipment delivery
delays and latent failures
Semiconductor Manufacturers
l Prevents equipment lockup
problems
l Increased yield due to ESD
damage and electrostatic
charge contamination
l Protects customers from
latent failures
ANSI/ESD S20.20 & SEMI E-78
l Not
explicitly stated
l SEMI E-78 ties into S20.20
– Grounding/Bonding
– Electric Fields
l Materials
l Ionization
l E-78
has some additional elements not
called out in S20.20
Overview of ANSI/ESD S20.20
Goal: Provide continuous ESD protection
l Administrative Requirements
– The “Plan”
– Training
– Compliance Verification (Audits/Inspections)
l Technical
l Tailoring
Requirements
Steps to Compliance with S20.20
l Develop
an ESD control plan
– Tie into the quality program (ISO 9000)
l Implement
the plan
– Training
– Installation of ESD controls
– Develop and begin inspections & audits
l Pursue
certification
(many ISO Auditors now offer S20.20 certification also).
The ESD Control Plan
The Plan should address each of the
requirements of the program
l Training
l Compliance Verification
l Technical Requirements
l Organizational Requirements
l Contractual Obligations
The Training Plan
All personnel involved in handling or
contacting ESDS items must be trained
l Initial
training
l Recurrent training (frequency determined by
organization – typically 1/year or 1/two-years)
l Documentation – retained in personnel records
l Type & content of training determined by the
organization.
Compliance Verification Plan
This makes sure the program continues to work
lInternal Audits
– Inspections
l
l
Frequency depends upon sensitivity and cost of failure
Typically performed by internal personnel
– Audits
lExternal Audits
Technical Requirements
l Grounding
/ Bonding Systems
l Personnel Grounding
l Protected Areas
l Packaging
l Marking
l Equipment
l Handling
Grounding / Bonding Systems
Equipment Ground
< 1.0 Ω (AC Impedance)
Auxiliary Ground
< 1.0 Ω (AC Impedance)
Equipotential Bonding
< 1.0 x 109 Ω
Common Point Ground
< 1.0 Ω (AC Impedance)
Personnel Grounding
Wrist Strap System
ESD S1.1
Ohmmeter
Stainless Steel
Electrode
< 35 x 106 Ω
Wrist
Strap
Ground
Cord
Drawing compliments of 3M
Personnel Grounding
Flooring / Footwear System
Resistance (ESD STM 97.1)
< 35 x 106 Ω
Body Voltage Generation
(ESD STM 97.2)
< 100 Volts
Graphical
Recording
Device
Ohmmeter
Charge
Plate
Monitor
Drawing compliments of 3M
91x91cm
(36x36 inch) or
Larger Flooring
Sample
Drawing compliments of 3M
Material 91x91cm
Under (36x36
inch) or
Test
Larger
Flooring
Sample
Protected Area
• Work Surface
< 1.0 x 109 Ω or < 200 Volts
• Wrist Strap Cord
0.8 x 106 - 1.2 x 106 Ω
• Footwear
< 1.0 x 109 Ω
• Flooring
< 1.0 x 109 Ω
• Seating
< 1.0 x 109 Ω
• Ionization (other than
< + 50 Volts Voltage Offset
room systems)
• Ionization (room
systems)
< + 150 Volts Voltage Offset
Protected Area (Continued)
• Mobile Equipment
< 1.0 x 109 Ω
• Continuous Monitors
Manufacturer Specification
• Signs
Required
• Equipment
• AC Powered Tools
< 1.0 Ω
• Battery Powered and
< 1.0 x 1012 Ω
Pneumatic Hand Tools
• Garment
1 x 105Ω > Resistance <1 x 1011Ω
• Humidity
30% < RH < 70%
Packaging
• Conductive
< 1.0 x 104 Ω
• Dissipative
> 1 x 104 to < 1 x 1011 Ω
• Shielding
< 50 nJ
• Low Charging
ESD ADV 11.2
• Protective Material Marking
EOS/ESD S8.1
Work Surfaces (ESD S4.1)
R < 1 x 109 ohm
Ohmmeter
3”
D
A
E
To: A, B, C, D, E
B
C
2”
2”
Resistance-to-Groundable Point - New Installations
Slide compliments of 3M
Work Surfaces (ESD S4.1)
R < 1 x 109 ohm
TABLE TOP
TABLE TOP
10”
10”
TABLE TOP
TABLE TOP
2”
2”
2”
2”
Resistance Point-to-Point - Installed Work Surfaces
Slide compliments of 3M
Footwear (ESD S9.1)
R < 1 x 109 ohm
Ohmmeter
One Sock Inside the Other Filled with Shot
Aluminum
Foil
Footwear Under Test
Insulator
Stainless Steel
Plate
Slide compliments of 3M
Flooring (A N SI/ESD S7.1)
R < 1 x 109 ohm
Electrode (5 lbs, 2.5” dia)
Groundable Point A
Groundable Point B
3
2
1
4
6
5
Resistance to Groundable Point Measurement
Slide compliments of 3M
Flooring (A N SI/ESD S7.1)
R < 1 x 109 ohm
Position
Position
A
3
2
1
B
4
6
5
Point to Point Resistance Measurement
Slide compliments of 3M
Seating (ESD STM 12.1)
1 x 105 ohm < R < 1 x 109 ohm
Rear of Back Rest
Ohmmeter
Back Rest
Electrode A
Seat
Foot Rest
Base
Electrode B
Conductive Casters
5”x10” Foot Plate
Drag Chain
Resistance to Groundable Point Positions
Slide compliments of 3M
Seating (ESD STM 12.1)
1 x 105 ohm < R < 1 x 109 ohm
3
4
3
4
1
1
2
5
2
5
Seat
Back Rest
1
2
1
2
3
Arm Rest
Rear of Back Rest
Any Location
3
4
2
5
Foot Rest
Base with Plastic
Covering
Note: If base is bare
metal, test only at
Position 1.
1
Seating Component Test Positions
Slide compliments of 3M
Ionization (ANSI EOS/ESD S3.1)
Offset Voltage < + 50 volts
Center Line of Test Points
60 cm
(24”)
Overhead Ionizer
Air Flow
45 cm
(18”)
Charge Plate
Monitor (CPM)
15 cm
(6”)
6”x6” Plate
Work Surface
Test Locations for Overhead Ionizer
Slide compliments of 3M
Ionization (ANSI EOS/ESD S3.1)
Offset Voltage < + 50 volts
30 cm
(12”)
30 cm
(12”)
30 cm
(12”)
30 cm
(12”)
Bench Top Ionizer
15 cm
(6”)
Air Flow
Work Surface
Test Locations for Bench Top Ionizer
Slide compliments of 3M
Garment (ESD STM 2.1)
1 x 105 ohm < R < 1 x 1011 ohm
Ohmmeter
Insulators
Clamps
Sleeve to Sleeve Resistance
Slide compliments of 3M
Garment (ESD STM 2.1)
1 x 105 ohm < R < 1 x 1011 ohm
Ohmmeter
Five Pound Electrodes
Insulative Surface
Point to Point Resistance
Slide compliments of 3M