Particulate contamination removal from wafers using plasmas and mechanical agitation

Patent · 31 December 1997

OSTI ID:872039

Selwyn, Gary S ^[1]

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1. Los Alamos, NM

Particulate contamination removal from wafers using plasmas and mechanical agitation. The present invention includes the use of plasmas with mechanical agitation for removing particulate matter from the surface of a wafer. The apparatus hereof comprises a mechanical activator, at least one conducting contact pin for transferring the vibration from the activator to the wafer, clamp fingers that maintain the wafer's position, and means for generating a plasma in the vicinity of the surface of the wafer, all parts of the cleaning apparatus except the mechanical activator and part of the contact pin being contained inside the processing chamber. By exposing a wafer to a plasma and providing motion thereto in a direction perpendicular to its surface, the bonding between the particulate matter and the surface may be overcome. Once free of the wafer surface, the particulates become charged by electrons from the plasma and are drawn into the plasma by attractive forces which keep them from redepositing. The introduction of a flowing gas through the plasma sweeps the particulates away from the wafer and out of the plasma. The entire surface is cleaned during one cleaning step. The use of an rf plasma to accomplish the particulate removal was found to remove more than 90% of the particulates.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM
• DOE Contract Number: W-7405-ENG-36
• Assignee: Regents of University of California (Los Alamos, NM)
• Patent Number(s): US 5849135
• OSTI ID: 872039
• Country of Publication: United States
• Language: English

Related Subjects

/156/134/
90
accomplish
activator
agitation
apparatus
attractive
attractive force
bonding
chamber
charged
clamp
cleaned
cleaning
cleaning apparatus
comprises
conducting
contact
contained
contained inside
contamination
contamination removal
direction
direction perpendicular
drawn
electrons
entire
entire surface
exposing
fingers
flowing
flowing gas
forces
found
free
gas
generating
inside
introduction
maintain
matter
means
mechanical
mechanical agitation
motion
overcome
particulate
particulate contamination
particulate matter
particulate removal
particulates
perpendicular
plasma
plasmas
position
processing
processing chamber
providing
redepositing
removal
remove
removing
removing particulate
rf
rf plasma
step
surface
sweeps
thereto
tractive force
transferring
vibration
vicinity
wafer
wafer surface
wafers