Martin Derks - Cleanroom Innovation · 1 Cleanroom Innovation 15 may 2012 Surface Cleanliness Martin Derks

1 www.golighthouse.com Cleanroom Innovation 15 may 2012

Surface Cleanliness

Martin Derks


Contamination Monitoring Solutions:

• Particles

• Airborne Molecular

Contamination

• Electrostatic Charge

• Electrostatic Discharge

• EMI

• Humidity

• Temperature

• Pressure

• Air Velocity

• Vibration

• Colony Forming Units

• TOC,pH, Resistivity

• And more…

Contamination: "Any foreign material or energy that has a

detrimental effect on a product or process”

Monitoring Solutions for:


Headquarters: Fremont, CA

Research and Development

Engineering

Pilot Production

Executive Management

Fremont

Medford


Lighthouse Benelux Boven Leeuwen


How Clean is Clean

"how clean is clean in relation to given

parameters?“

"how clean is clean enough?”

"how clean are the results of one cleaning

process compared to another cleaning

process?"


Particles

Solid aerosol particles are all

around us.


N/log(d) = 24.0d-3.08

Distribution of Aerosol Particles

>20µm = Gravitational influence dominates

<0.1µm = Electrostatic attraction and diffusion dominates


Optical Particle Counting

Particle Counter ANNO 1880


OK monitoring systemen


0,0

200000,0

400000,0

600000,0

800000,0

1000000,0

1200000,0

1400000,0

1600000,0

1800000,021-1

0-2

008 0

0:0

5:2

3

21-1

0-2

008 0

1:4

5:2

3

21-1

0-2

008 0

3:2

5:2

3

21-1

0-2

008 0

5:0

5:2

3

21-1

0-2

008 0

6:4

5:2

3

21-1

0-2

008 0

8:2

5:2

3

21-1

0-2

008 1

0:0

5:2

3

21-1

0-2

008 1

1:4

5:2

3

21-1

0-2

008 1

3:2

5:2

3

21-1

0-2

008 1

5:0

5:2

3

21-1

0-2

008 1

6:4

5:2

3

21-1

0-2

008 1

8:2

5:2

3

21-1

0-2

008 2

0:0

5:2

3

21-1

0-2

008 2

1:4

5:2

3

21-1

0-2

008 2

3:2

5:2

3

OK 8 0,5 micron

Alarm

Activiteiten…….

Alarmering?


0,0

20000,0

40000,0

60000,0

80000,0

100000,0

120000,0

140000,0

20-1

0-2

008

00

:05:2

3

20-1

0-2

008

18

:35:2

3

21-1

0-2

008

13

:05:2

3

22-1

0-2

008

07

:35:2

3

23-1

0-2

008

02

:05:2

3

23-1

0-2

008

20

:35:2

3

24-1

0-2

008

15

:05:2

3

25-1

0-2

008

09

:35:2

3

26-1

0-2

008

03

:05:1

3

26-1

0-2

008

21

:35:1

3

27-1

0-2

008

16

:05:1

3

OK 8 5,0 micron

OK 8 Inleiding 5,0 micron

Deeltjes ≥ 5,0µm

Schoonmaak probleem.

Alarmering?


Deeltjesneerslag

Afmeting in

µm

Gemiddelde valsnelheid ronde deeltjes in stilstaande

lucht

Valsnelheid in

mm/s Valtijd over 1 m tijd

0.5 0,01 25 uur

1 0,04 8 uur

5 0,7 25 min

10 3 6 min

20 12 83 sec

50 75 13 sec

100 300 3 sec


Deeltjes depositie vs Oppervlakte reinheid

DDK Deeltjesdepositie klasse

DDK is de toename van het aantal deeltjes per dm² per

uur op een testoppervlakte

Als basis voor de klasse is 1µm gekozen

DDK is hulpmiddel om risico van contaminatie

doorneerslag van deeltjes te bepalen:

RISICO: = bloodstellingstijd

DDK 100 betekent: 10 deeltjes >10µm per dm² per uur

2 deeltjes >50µm per dm² per uur

1 deeltje> 100µm per dm² per uur


Relative Size

Human

Blood Cell

7 Micron

Virus 0.1

Micron

E-Coli 0.5 Micron

Andenovirus

0.075 Micron

Micron Scale1020304050 1

Human Hair

50 -100 Micron

35 Micron

Visible

Particles


0.3 µm

particle

0.1 µm

particle

Gas Molecules (AMC)

2-50 Å (.0002-.005µm)

Relative Size


Personeel als grootse Vervuiler

★ 5 tot 10 miljoen huidcellen per dag (30 gram)

★ 2300 micro-organisme per cm²

★ ≥ 25µm vallende deeltjes

★ ≤ 5µm zwevende deeltjes

★ Tussen 5µm en ≥ 25µm overgangsgebied


Surface Testing Methods: Non-Standard

Surfaces

★ Some Surfaces May Be Located in Hard to Reach

Areas

★ Some Parts May Be Too Small

★ Alternate Testing Methods May Be Used

1. Tape Lift

2. Part Rinse


Deeltjes Depositie Klasse


Surface Particle Cleanliness

Class ISO14644-9 SPC


Deposited particles can have a greater impact on high-technology

manufacturing processes than airborne particles.

Witness plates

A witness plate is a flat, particle-free

object made from the same materials as

the product being manufactured (for

example: if you make ABS plastic

products, you should use ABS plastic

witness plates).


wafer inspection system

> 0,1µm


PartSense: Portable System

> 2,0µm


Measuring Principle: Technique • Illumination with

Glancing Light

• Fading out the rough surface

• Imaging of the Particles Using Optics

• Image Recording Using a Digital Camera

• Analysis of the Images Using Digital Image Processing


Measuring Principle

> 25µm


Surface Cleanliness

qualification method

GSA 07 4320

Grade 4 cat. 1, 2 & 3

UV-A Blacklight inspection GSA 07 0012


Fluorescentie

Camera

Filter

UV light source

λ 375nm

λ

400/500

nm


Application area :

Grade 1, 2, 3, and 4

Measurement area : 100 x 100 mm

Every surface / substrate can be measured,

except fluorescent one’s. ( only when the tool can be

placed correctly, stray light should be eliminated ! )

Roughness / reflectivity of the substrate is not an

issue.


P.A.C. ( Percentage of Area Covered )

Size of the individual fluorescent particle’s on the surface

Number of fluorescent particle’s on the surface.

Length and width of the individual fluorescent particles

Measurements are reproducible

Ability to do a qualitative check of a surface’s particle

contamination and have immediate feedback OK or NOK

Functionality :


UV Surface Particle Counter

- Produced by Lighthouse

- Developed by ASML

Only UV (λ 375nm) fluorescent particles

/ fibers can be seen with the tool.

(range is 400 / 900 nm light )


Substrate is a Circuit Board with

Components.


Circuit Board with Components,

Detail from previous slide.


★ Specification = 4 particles/dm2

★ Product

★ 1dm2

no action required Cleaning needed 4 particles/dm2 6 particles/dm2

Product surface = 1 dm2

R Q



★ Product 0.5 dm2

★ 1dm2

no action required Cleaning required 4 particles/dm2 6 particles/dm2

GSA 07 4320 vs Area size Product surface < 1 dm2

R Q

Calculation = amount of detected particles x (1

dm2 / product area)

eg 6 = 3 X (1/0.5) = 3 X 2



★ Product 4 dm2

★ 1dm2

GSA 07 4320 vs Area size Product surface > 1 dm2

R

no action required

4 particles/dm2



★ Product 4 dm2

★ 1dm2

R

CLEANIN

G

NEEDED!

Q

! GSA 07 4320 vs Area size Product surface > 1 dm2


Particle Fallout prediction

Particle deposition on critical surfaces affect the functionality

of ASML scanners..

The simple mechanism of PFO spread at ASML cleanrooms:

Production

Activities Particle

generation

Airborne

contamination

Nc (particles/m3)

Time & Space

dependent

deposition

PFO rate

ṅ (particles/m2/time)

The project involved experimental modeling of this

mechanism to establish a relationship between Nc and ṅ of the

form shown below: cn( x m,t) (N ) t (Distance)


witnesswafers

Particle

Counters

0,1µm

Dust feeder


Surface Particle Counter


Vezel 50µm Particles


Resultaat metingen:

- DNK (Deeltjes Neerslag Klasse)

- ORK (Oppervlakte Reinheid Klasse)

- Deeltjeslijst ( positie deeltje en eigenschappen)

- Aantal deeltjes per klasse


Surface Particle Probe Counter



Thank You

Documents

Martin Derks - Cleanroom Innovation · 1 Cleanroom Innovation 15 may 2012 Surface Cleanliness Martin Derks