[labnetwork] Evaluation of heavy metal contamination in oxidation furnace

[Jerry Hunter]

TXRF will detect metallic contamination on the very surface down to ppm levels.

If you are looking for more the bulk (>5nm) of the film with depth profiling then SIMS is a better choice (as long as the concentration is less than 1%) and will give you detection down to ppb levels. If the concentration is > 0.1% then XPS is a good choice and easier to do than SIMS.

Jerry Hunter

On Apr 13, 2023, at 6:42 PM, Lino Eugene <lino.eugene at uwaterloo.ca> wrote:


Hi all,

We have a Tystar furnace dedicated to thermal oxidation. We do not have a chlorine source for tube cleaning. So far, only bare prime Si wafers cleaned in RCA solutions have been loaded in the furnace. MOS capacitors with 20 nm thermal oxide were fabricated and C-V measurements did not show hysteresis due to mobile ions and I-V measurements showed nice Fowler-Nordheim curves up to 20 V with no breakdown . Quasi-static CV curves showed low density of interface traps. We tried the Zerbst method to determine the minority carrier lifetime generation but somehow it did not work.

For those of you who care about metal contamination in quartz furnaces, I am curious to know how you evaluate it. I learned about surface charge analyzing that can work on bare and dielectric coated wafers and measure the minority carrier lifetime. I have contacted Berkeley and Georgia Tech for a characterization service. I am also considering TXRF (Total X-ray Fluorescence) but the cost to analyze few wafers with a specialized analytical company is quite high.

Any suggestion is welcome.

Best,

Lino Eugene, P.Eng., Ph.D.,
Micro/nanofabrication process engineer
Quantum-Nano Fabrication and Characterization Facility
Office of Research
QNC 1611
University of Waterloo
200 University Avenue West
Waterloo, ON, Canada
N2L 3G1

Ph: +1 519-888-4567 #37788
Cell: +1 226-929-1685
Websites:
https://uwaterloo.ca/quantum-nano-fabrication-and-characterization-facility/
https://fab.qnc.uwaterloo.ca/

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