|
MAXIMILIAN A. BIBERGER & PAUL SCHILLING, Supercritical Systems Inc., Fremont, CA, USA
DON FRYE & MICHAEL E. MILLS, The Dow Chemical Company, Midland, MI, USA ABSTRACT
A
novel cleaning technology for removing photoresist and photoresist
residue from semiconductor wafers is introduced. This cleaning
technology is a non-plasma, environmentally friendly technology using
supercritical CO2 (SCCO2) and co-solvents to clean the substrates. The
wafers are being cleaned in a single wafer, 300 mm compatible chamber
under moderate pressures, between 8.6 MPa and 19 MPa, and moderate
temperatures, between 40ºC and 70ºC. Cleaning with SCCO2 and
co-solvents is a "dry in - dry out" process technology, consisting of a
cleaning and a rinsing / drying step performed in the same chamber with
a total processing time between two and four minutes, depending on the
application.
The above mentioned processing times include
pressurisation and de-pressurisation of the chamber. It was
demonstrated that the co-solvent usage is in the range of 10 ml to 40
ml per wafer run and that the amount of co-solvents, as well as the
time for cleaning and rinsing / drying, is independent of the sample
size (wafer chips versus a whole 200 mm wafer). Cleaning with SCCO2 and
co-solvents was successfully applied to a broad range of applications
from front end applications (ion implant) to dual damascene Cu
technology with standard oxides and low-k materials. Based on the
results to date, cleaning with SCCO2 and co-solvents has the potential
to combine ashing and wet cleaning into one process step, overcoming
the potential shortcomings of ashing and wet cleaning with respect to
high aspect ratio features, dual damascene and low-k technology, and
reducing the amount of solvents and water dramatically, resulting in an
enabling, very cost effective cleaning technology.
 Photoresist and Photoresist Residue Removal with Supercritical CO2- A Novel Approach to Cleaning
|
Wafer Processing 
