Fluid MeasurementTechnologies, Inc.

Introducing a 10-nm Particle Counter for Ultrapure Water

Derek Oberreit PhD, David Blackford PhDFluid Measurement Technologies, Inc.

Gary VanSchooneveld, Mark Litchy, Don GrantCT Associates, Inc.

Outline

•

Overview of the state of the art in in-situ particle counting

•

Overview of particle counting in the gas phase

•

Description of threshold particle counting•

Description of the Scanning Threshold Particle Counter (Scanning TPC)

•

Review of sample data

Can existing

technology get us here?

Liquid Particle Counting Technologies

•

Dynamic light scattering–

Requires high concentrations•

Optical particle counting–

Specified down to 25nm with 3-5% detection efficiency–

Sensitive to particle composition•

Acoustic Coaxing Induced Microcavitation–

Able to detect 20nm particles–

Commercial availability unknown•

Nebulization

–

Aerosolization

–

Condensation

Particle Counting–

Promising new technology to provide measurements at previously unattainable size thresholds

Particle analysis in the gas phase•

John Aitken, in 1888, showed a method for detecting and counting optically invisible, nanometer size aerosol particles by enlarging them via heterogeneous condensation of a supersaturated vapor

http://www.iara.org/AerosolPioneers.htm

Condensation particle counting… the science

•

Supersaturated vapors (relative humidity greater than 100%) are not happy

•

The vapor wants to leave the gas phase and condense onto a surface

•

Curved surfaces are energetically less favorable due to added surface tension work (Kelvin effect)

•

Condensation onto particles is a function of the surface radius and the degree of supersaturation

W=σdA

Condensation particle counting more science

•

The particle radius threshold at which a supersaturated vapor will condense onto its surface is given by

where γ

is the surface tension and Vm

is the molecular volume of the condensing liquid. Po

is the vapor pressure above a flat surface of the condensing vapor and P

is the actual vapor pressure

•

P/Po

is the Saturation Ratio, S•

Varying the degree of S

changes the minimum enlarged particle size

PP

TkV

r o

B

vap ln2

r

S=Scritical,r

Condensation Particle Counting how it is implemented

•

Lewis number is the ratio of the thermal diffusivity of a gas λ, to the

mass diffusivity of a vapor D, Le= λ/ D

•

Le < 1 (e.g. water in air), cold saturated gas introduced to warm wet walls will drive vapor into gas faster than heat, leading to S>1

•

Le > 1 (e.g. butanol

in air), warm saturated gas introduced to cold walls will pull heat out of the gas faster than butanol

vapor, leading to S>1

TSI Incorporated 3772 CPC Brochure

A note on detection efficiencies•

OPCs

have a

shallow detection efficiency curve

•

Many OPCs are specified at

less than 5% detection efficiency

•

Condensation Particle Counters (CPCs) are specified at their 50% cutoff

3772 CPC 50% Detection Efficiency at

10 nm

OPC data provided by Particle Measuring Systems.3772 CPC Data by CT Associates

Detection Efficiency Comparison between in-situ OPC and CPC

Scanning Threshold Particle Counter (Scanning TPC)

Principle of Operation

UPW

Nebulization Large Droplet Removal Evaporation

Size Selective Condensation

Growth

Optical Detection

Non-volatile Residue Monitor

Threshold Particle Counter

ScanningTPC Principle of Operation

•

Size selective growth–

All particles entering Condensation Particle Counter (CPC) are optically ‘invisible’–

Particles larger than a threshold size will grow by orders of magnitude through vapor condensation

–

Threshold size can reach as low as 1 nm!–

Scanning through different threshold diameters leads to a cumulative size distribution

•

Non-volatile residue limits lowest threshold diameter setting

Size Selective Condensation

Growth

Particle Diameter

ColloidParticles

Non-Volatile Residue Particles

ScanningTPC Principle of Operation

•

Stepping threshold diameter range currently 10 nm to 30 nm

•

Lower threshold diameters possible with low residue UPW

•

Higher threshold diameters also possible

Channel 2

Channel 3

Particle Diameter

100% Detection

Particle Diameter

100% Detection

Diameter

Cum

ulat

ive

#/m

L

Channel 1

Particle Diameter

100% Detection

Diameter

Cum

ulat

ive

#/m

L

Diameter

Cum

ulat

ive

#/m

L

ColloidParticles

Non-Volatile Residue Particles

Aero

sol P

artic

le C

once

ntra

tion

Colloid Particles

Non-Volatile Residue Particles

ColloidParticles

Non-Volatile Residue Particles

Predicted particle sizes (150, 300, 600 ppt)

1.E+01

1.E+02

1.E+03

1 10 100

Size (nm)

dN/d

logD

p0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Perc

ent d

etec

ted

by 3

772S TPC

S TPCS TPCLNS #6LNS #6LNS #6Det eff

Scanning TPC Nebulizer Design

Upper tail of droplet distribution removed to minimize dissolved non-volatile residue particle counts

Secondary large droplet removal incorporated downstream of nebulization

region

Scanning TPC Response to dissolved NVR

•

High levels of DNVR will lead to false particle counts

•

Plot shows little sensitivity to low levels of added NVR (some true colloidal particles will be present due to injection system and impurities in the KCL)

Scanning TPC Response to injected KCL

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

0.1 1 10 100 1000 10000 100000

Dissolved NVR over 150 ppt background (ppt)

Rep

orte

d pa

rticl

e co

unts

(#/m

l) > 10 nm> 15 nm> 20 nm

Offline Data Inversion Option•

Monte-Carlo method may be used to estimate the true particle size distribution

•

Accounts for shape of detection efficiency curve

•

Accounts for shape of droplet size distribution

•

Finds best fit of a defined colloid size distribution to match measurements

Channel 1

Particle Diameter

100% Detection

Diameter

Cum

ulat

ive

#/m

L

D50

TPS Data Inversion Example

0.0E+00

5.0E+05

1.0E+06

1.5E+06

2.0E+06

2.5E+06

3.0E+06

3.5E+06

4.0E+06

0 5 10 15 20 25 30 35

Particle Diameter

#/m

l

Measured valuesInverted values

TPS Data Inversion Example

0.0E+00

5.0E+05

1.0E+06

1.5E+06

2.0E+06

2.5E+06

3.0E+06

3.5E+06

4.0E+06

0 5 10 15 20 25 30 35

Particle Diameter

#/m

l

Measured valuesInverted values

Scanning TPC Sample Data Colloid Size Standards

•

High concentration solutions of colloidal silica and gold nanoparticles

prepared for testing

•

Size distributions of each of the solutions has been characterized using Liquid Nanoparticle

Sizing

(LNS) technology–

US Patents 8,272,253 and 8,573,034

•

Use LiquiTrak

®

Precision Diluter to

provide high purity, online dilution.

Particle Diameter (nm)

5 10 20 30 40 50

Diff

eren

tial n

umbe

r wei

ghte

d di

strib

utio

n(d

(#/m

L) /

d lo

g(D

p))

0.0

5.0e+11

1.0e+12

1.5e+12

2.0e+12

2.5e+12

3.0e+12

Particle Diameter (nm)

5 10 20 30 40 50

Diff

eren

tial n

umbe

r wei

ghte

d di

strib

utio

n(d

(#/m

L) /

d lo

g(D

p))

0.0

2.0e+16

4.0e+16

6.0e+16

8.0e+16

ScanningTPC

Sample Data Colloid Size Standards

Particle Diameter (nm)

5 10 20 30 40 50

Diff

eren

tial n

umbe

r wei

ghte

d di

strib

utio

n(d

(#/m

L) /

d lo

g(D

p))

0.0

5.0e+14

1.0e+15

1.5e+15

2.0e+15

2.5e+15

Particle Diameter (nm)

5 10 20 30 40 50

Diff

eren

tial n

umbe

r wei

ghte

d di

strib

utio

n(d

(#/m

L) /

d lo

g(D

p))

2.0e+16

4.0e+16

6.0e+16

8.0e+16

1.0e+17

1.2e+17

1.4e+17

12 nm Silica 20 nm Silica 30 nm Silica

30 nm Gold

Particle Diameter (nm)

5 10 20 30 40

Diff

eren

tial n

umbe

r wei

ghte

d di

strib

utio

n(d

(#/m

L) /

d lo

g(D

p))

0.0

1.0e+14

2.0e+14

3.0e+14

4.0e+14

40 nm Gold

Data provided by CT Associates using Liquid Nanoparticle

Sizing methodology

ScanningTPC

Sample Data Sensitivity

•

Threshold diameter set to 10nm

•

The system responds to all particles with an attenuated response for the 12 nm particles

10nm Threshold Diameter1E8 #/mL Colloidal Silica Injections

0.0E+00

2.0E+07

4.0E+07

6.0E+07

8.0E+07

1.0E+08

1.2E+08

1.4E+08

1.6E+08

1.8E+08

2.0E+08

12:21 12:28 12:36 12:43 12:50 12:57 13:04 13:12

Parti

cles

/mL 12nm

20nm 30nm

ScanningTPC

Demonstration Sensitivity

•

Threshold diameter set to 20nm

•

The system shows little or no response to the 12nm particles, attenuated response to the 20nm particles and 80% detection of 30 nm particles.

20nm Threshold Diameter1E8 #/mL Colloidal Silica Injections

0.0E+002.0E+07

4.0E+07

6.0E+07

8.0E+07

1.0E+081.2E+08

1.4E+08

1.6E+08

1.8E+08

2.0E+08

11:16 11:24 11:31 11:38 11:45

Parti

cles

/mL

12nm

20nm

30nm

ScanningTPC

Sample Data Scanning Operation

•

Operated TPC in mode that steps through threshold particle diameters

•

Mixture of 12, 20, and 30 nm particles at equal concentrations

Scanning Mode1E8 #/mL Mixed Colloidal Silica Injection

0.0E+00

2.0E+07

4.0E+07

6.0E+07

8.0E+07

1.0E+08

1.2E+08

1.4E+08

1.6E+08

1.8E+08

17:25 17:28 17:31 17:34 17:36 17:39 17:42 17:45 17:48 17:51

Parti

cles

/mL

10nm

15nm

20nm

ScanningTPC

Sample Data UPW Monitoring

•

Instrument installed on small scale, semiconductor grade UPW system at CT Associates

•

Good stability observed

•

Distribution of particle sizes apparent

•

Large scale UPW systems ~4X lower

UPW System Monitoring

1.E+05

1.E+06

1.E+07

0:00:00 2:24:00 4:48:00 7:12:00 9:36:00 12:00:00 14:24:00

Time

Part

icle

Con

cent

ratio

n (#

/ml)

> 10 nm> 15 nm> 20 nm

Scanning TPC Filter Testing

•

Single channel mode

>10 nm•

Shows material dependent retention of 30 nm particles

Fractional coverage (Monolayers)

0.000 0.025 0.050 0.075 0.100 0.125 0.150 0.175 0.200

Ret

entio

n (%

)

0

20

40

60

80

100

SilicaPSLGold

30 nm Rated Water Filter Challenged with 2E8 #/ml ( 6ppm) 30nm Particles

Scanning TPC Pros and Cons

•

Pros–

Particle composition independence

–

No dependence on refractive index or particle shape–

Wide dynamic range

•

Cons–

Low sample volume rate (~1 μl / min)

–

Requires Butanol

as a consumable–

Lower threshold limit is sensitive to amount of dissolved non volatile residue

Further development

•

Increase inspection volume•

Further characterization of operating parameters

•

Refinement and automation of optional offline data inversion software

FMT Model 1000 LiquiTrak®

Scanning TPC

•

Internal data logging•

Touchscreen

display–

Set nebulizer temperatures

–

Monitor and log pressures and temperatures

–

Adjust minimum detected particle size

–

Display particle counter concentration and trend lines

–

Set scan rates•

Patent pending

Thank you

Questions?

BibliographyGrant DC (2008). “A New Method for Determining the Size Distribution of the Working Particles in CMP Slurries,”

presented at the 2008 CMP Users Conference, sponsored by Levitronix.

Don Grant and Uwe Beuscher (2009), “Measurement of Sub-50 nm Particle Retention by UPW Filters”, Ultrapure Water Journal, 26(11):34-40.

Blackford D and DC Grant (2009). “A proposal for measuring 20-nm particles in high-purity water using a new technology,”

Ultrapure Water, January 2009.

Grant DC, DC Chilcote

and U Beuscher (2012). “Removal of 12 nm particles from UPW by a combination of Ultrafiltration

Modules and Microfiltration Cartridges,”

Ultrapure Water Journal, May/June 2012.

Rastegar, A (2013). “Particle Control Challenges in UPW ”, presented at 2013 UPW Micro Conference

Patents US 8,272,253; US 8,573,034; US 7,852,465; Other patents pending

Scanning TPC

Long Term Stability

System Background - 2014

Date

01/06/14 01/20/14 02/03/14 02/17/14 03/03/14 03/17/14 03/31/14

Con

cent

ratio

n (#

/mL

> 10

nm)

0

1e+6

2e+6

3e+6

4e+6

5e+6

6e+6

Filter test systemUpper 95% CLMeanLower 95% CL

ScanningTPC

Sample Data Material Independence

•

Inject 30 and 40 nm colloidal gold nanoparticles

•

Response similar to colloidal silica

20nm Threshold DiameterColloidal Gold Injections

0.0E+00

2.0E+07

4.0E+07

6.0E+07

8.0E+07

1.0E+08

1.2E+08

1.4E+08

1.6E+08

1.8E+08

2.0E+08

12:28 12:43 12:57 13:12 13:26 13:40 13:55 14:09 14:24 14:38

Parti

cles

/mL

1E7 #/mL30 nm Gold

1E8 #/mL40 nm Gold

5E7 #/mL30 nm Gold

UPW

ScanningTPC

Sample Data Linearity

•

Dilution ratios varied over a 16X range

Linearity30nm Colloidal Silica challenge

y = 3E-07x + 16.846R2 = 0.9958

0.0E+00

2.0E+01

4.0E+01

6.0E+01

8.0E+01

1.0E+02

1.2E+02

0.0E+00 1.0E+08 2.0E+08 3.0E+08 4.0E+08

Particle Injection concentration (#/mL)

CPC

Par

ticle

s / c

m^3

Scanning TPC Single Channel Performance

Installation of Ultra Filters at a Semiconductor Facility

Scanning TPC Single Channel Performance

Resin Rinse Down

Flush Volume (liters UPW)

1 10 100 1000

Cum

ulat

ive

Par

ticle

Con

cent

ratio

n A

dded

(#

/mL

> 10

nm

)

1e+5

1e+6

1e+7

1e+8

1e+9

Resin AResin BResin CResin DResin EResin FSpool

Flush Volume (liters)

1 10 100 1000

Non

-vol

atile

resi

due

adde

d (p

pt)

10

100

1000

10000

Resin AResin BResin CResin DResin EResin FSpool

Particle Rinse Non-volatile Residue Rinse

Data prepared and presented by CT Associates to the SEMI Ion Exchange Task Force on 02/27/2014