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Isonics Silicon Products and
Services Division -
Reclaim Process Flow
Sorting and Incoming Inspection
 The
Isonics wafer reclaim process ensures that wafers will remain
contaminant free throughout the entire wafer reclaim cycle. We
start with 100% visual inspection of the wafers. This visual
inspection of all wafers provides critical information on wafer
films and possible wafer damage; this inspection is also our first
line of protection against possible wafer or equipment
contamination. We guarantee that Isonics reclaim wafers can be
placed directly in use in your fab with high confidence in their
quality and safety.
Reclaim Wafer Preparation
 After
a thorough inspection of incoming silicon wafers, the appropriate
chemistry is determined to remove existing oxide, films or
patterns. This may include a piranha solution for organic matter,
or an alkaline or acid etch as required to remove films. This
preparation brings bare silicon to the wafer surface as originally
manufactured. As an additional fail-safe, Isonics applies a
pre-treatment to reclaim wafers that may contain metal films (such
as Al) to ensure that wafers enter the wafer reclaim line metal
free.
Wafer Surface Restoration
 Occasionally
the silicon wafer surface requires lapping or grinding to remove
films from wafers slated for reclaim. Isonics uses
state-of-the-art equipment for wafer grinding and lapping assuring
optimal surface condition, better stress relief, and low material
removal. Isonics Wafer Thinning is a natural extension of our
expertise in wafer surface conditioning. We have been recognized
by the EMC-3D industry consortium as their vendor of choice for
wafer thinning with capabilities down to 75um for 100mm and 200mm
wafers and down to 200um for 300mm wafers. For more information
see http://www.emc3d.org/
Polishing
 Based
on our customer's wafer reclaim specifications, Isonics will
provide single side or double side wafer polishing resulting in a
high-quality finish with optimal flatness across the wafer. Our
double side polishing achieves the lowest total thickness
variation (TTV) and our single side polishing ensures a high
quality front surface while preserving the condition of the
backside of the wafer. We tailor our wafer polishing process for
each customer to provide the minimum removal possible to achieve
the desired specification. This results in maximum wafer reuse
cycles for our customers.
Ultra-Pure and Ultra-Clean
 Following
wafer polishing, reclaim wafers are moved to the Isonics Class 1
Clean room where they are cleaned in multiple stages. Isonics uses
fresh chemistry (cleaning agents) or single pass cleaning, for
each run to prevent cross-contamination. Our cleaning process
ensures low particle counts and we guarantee surface metal levels
of less than 5e10 atoms per cm2. Typically Isonics wafer cleaning
performs at even lower surface metals of less than 1e10 (below
detection limit) for most customers.
Inspection
 Wafer
particles, or light point defects (LPDs) are measured by an
industry standard laser particle scanner including our newest KLA
Tencor SP1. Isonics actually has two KLA SP1s on site in
Vancouver, a model SP1-DLS and a SP1-TBI, the same models used by
leading semiconductor manufacturers in their fabs. The Isonics
wafer reclaim process is capable of achieving very low particulate
levels, LPDs below 50@0.080 um or 30@0.12 um for 300mm reclaim
wafers is possible. As part of our Wafer Reclaim Quality
procedure, we conduct storage simulation tests to ensure the
wafers remain clean even after extended storage periods
(simulating >12 month worst case scenarios).
Data Integrity and Reporting
 Isonics
provides a comprehensive report on our wafer reclaim products; the
C of A (certificate of analysis) reports the results by lot.
Isonics can also provide custom reporting as needed:
- Reconciliation report of wafer yields
- Wafer Metrology
- Full histogram data
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