Zeta Plus™ 40Q
Purifier Cartridges
Superior Removal of Trace Metals From High Purity Chemicals
Zeta Plus 40Q purifier cartridges are high capacity purifiers designed to remove metallic
ion contaminants from high purity chemicals such as resins, photoresists, and solvents in
a single pass. The purifier contains ion exchange groups that have been bonded within
a porous depth media structure. This construction enhances surface area for the ion exchange groups assuring metallic contaminant removal to single digit ppb levels.
Zeta Plus 40Q Purifier Cartridge Vs Ion Exchange Columns
Ion exchange columns, a process step commonly used to remove trace metal ions
from high purity chemicals are often the limiting factor in reducing the manufacturing cycle. Ion exchange columns are comprised of resin beads, which typically have
a particle size distribution ranging between 0.3 mm and 1.2 mm in diameter, and are
packed into a column. When the resin beads are packed into the column they cause a
high differential pressure as the highly viscous fluid flows down through the column.
Because a finite space exists between ion exchange resin beads, void or interstitial
volume is formed. When a high purity chemical is introduced to the ion exchange
column, the fluid will take the path of least resistance through the column, which is
commonly referred to as “channeling”. To minimize the channeling effect, the ion exchange column is operated at a very low flow rate which in turn increases the contact
or “residence time” with the fluid. Residence is described as the period of time when
the fluid and functional sites of the ion exchange resin are in contact. Even with low
flow rates and long residence times, ion exchange columns typically cannot reduce the
Features & Benefits
Zeta Plus 40Q Metal Ion Removal Media
n Removes trace metals to single digit ppb levels
n Superior metal removal capacity, lower cost-of-ownership
Graded Density Construction
n Large surface area increases contact time between the fluid and reactive sites of the purifier
n Increased Purifier lifetime
High Flow Rates
n Increased throughputs as compared to ion exchange columns
Wide Range of Configurations
n Allows for the same purification media to be used during laboratory, pilot and full production
scale-up
n Low hold-up volume disk filters allow material suppliers to perform testing in a rapid and cost-
effective manner
n Purification media can be customized to the specific application
Low Cartridge Extractables
n No leaching of contaminants into the process fluid
Quality Manufacturing
n ISO 9001:2008 Registered Quality Management System.
n Repeatable and reliable performance
Applications
Resins
Solvents
Recirculation Baths
I Line Photoresists
G Line Photoresists
Ancillary Chemicals
Acetone
DI Water
IPA
Plating Solutions
Post CMP Clean
Water Reclaim
Table 1: Single Pass Metals Removal from
PGMEA/PGME (30/70 Mixture)
Metal
Ca 0.2 15 < D.L.
Cr 0.2 10 < D.L.
Cu 0.2 9 < D.L.
Fe 0.2 9 < D.L.
Mg 0.2 8 < D.L.
Mn 0.2 11 < D.L.
Na 0.2 9 1.6
Pb 0.2 10 < D.L.
Zn 0.2 7 < D.L.
* Detection Limit
Detection
Limit (ppb)
Al 0.2 10 < D.L.*
K 0.2 8 < D.L.
Ni 0.2 8 < D.L.
Influent
Level (ppb)
Effluent
Level (ppb)
Table 2: Single Pass Metals Removal from
PGMEA
Metal
Ca < 10 1160 < D.L.
Fe < 10 838 < D.L.
Na < 10 902 < D.L.
Detection
Limit (ppb)
Influent
Level (ppb)
Effluent
Level (ppb)
Table 3: Single Pass Metals Removal from ECA
Metal
Ca < 10 590 < D.L.
Fe < 10 230 < D.L.
Na < 10 850 < D.L.
Detection
Limit (ppb)
Influent
Level (ppb)
Effluent
Level (ppb)
Table 4: Extractable Metals Content of
Zeta Plus 40Q Purifier Cartridge in PGMEA
Metal
Ca 4.0 < D.L.
Cr 2.0 < D.L.
Cu 1.0 < D.L.
Fe 5.0 < D.L.
K 1.0 < D.L.
Na 5.0 < D.L.
2
Detection Limit
(ppb)
Effluent Level
(ppb)
trace metal content to the required specification levels in a single pass. One reason for
this is that the ion exchange resin beads have a relatively low surface area to volume
ratio and another reason is that a large void volume exists between each resin bead.
When these two factors are combined the process fluid is not able to fully access the
ion exchange sites thereby resulting in a less efficient means of purification. For this
reason, it is often necessary to run the ion exchange column in re-circulation mode until the required parts-per-billion levels for trace metals is achieved. This is particularly
true with high viscosity chemicals. While this technology is effective at reducing trace
metal and ionic contaminants it lacks the throughput that material suppliers require.
During the manufacturing process, molecules carrying a positive charge are
chemically bonded to the filter matrix permanently forming an interconnected filtration structure with positively charged electrokinetic capture sites. The resulting porous
depth filter is a tortuous network of charge-enhanced flow channels capable of removing
bacteria, particulate, cellular debris and submicronic contaminants to a level which mechanical screening alone cannot achieve.
3M Purification has developed a chemically modified purifier that is capable of
removing metallic or ionic contaminants from photoresists, resins, solvents, and
ancillary chemicals while improving flow and throughput. This is accomplished by
maximizing purification surface area, which reduces the potential for channeling and
increases the contact time between the chemical and reactive sites of the purifier. This
increase in purification surface area is achieved by using the Zeta Plus 40Q purifier
cartridge metal ion removal media.
Superior Metals Removal Capacity Provided by Zeta Plus 40Q Purifier Cartridge
Zeta Plus 40Q purifier cartridges contain multiple ion exchange groups that reduce
trace metals such as Na, Fe, K, and Ca to single digit parts per billion levels in single
pass or recirculation mode applications. Unlike competitive purifiers that only contain
ion exchange technologies on the surface of the media, Zeta Plus 40Q purifier cartridges are able to purify ionic contaminants throughout the entire depth of the media.
This design provides a more efficient means of purification per surface area while
increasing flow and lifetime. Tables 1, 2, and 3 show the metal removal performance
of Zeta Plus 40Q purifier cartridge in propylene glycol monomethyl ether acetate
(PGMEA), propylene glycol monomethyl ether (PGME), and ethyl cellosolve acetate
(ECA). Metals removal was quantified using a graphite furnace atomic absorption
spectrometer.
Zeta Plus 40Q Purifier Cartridge Extractables
The purifier’s clean materials of construction ensure that ionic, organic, and metallic
contaminants are not being added back into the process chemical. Ionic, organic, and
metallic contaminants can extract from other filter materials, which may change the
photo-speed, viscosity, or molecular weight of the chemical. A static soak test was performed to determine the amount of contaminants extracted from the solvent PGMEA.
After a 24-hour static soak, extractables were quantified using a graphite furnace
atomic absorption spectrometer (Table 4).
Zeta Plus 40Q Purifier Cartridge Purifier Scale-Up
For laboratory and pilot scale testing, 3M Purification offers low hold-up volume Zeta
Plus 40Q purifier disks (47mm, 90mm, 142mm) and housings to allow end users to assess parameters such as material compatibility, photo-speed, and trace metals removal
in a rapid and cost effective manner. The compact size allows for easy replacement and
installation of purification media while reducing the waste of expensive chemicals.