ASML Litho Particle Summary
Using the SRD after wafers contact anything along svg tracks reduces particle count significantly.
The particle tests show that wafers ran on the track, then cleaned with q-tips and acetone (when needed on the back of the wafers) and SRD had 2/3 of their particles removed.
Sources of particles
|Svgcoat, no swab/SRD (reference)||Svgcoat & swab/SRD||SRD on clean wafer (no svgcoat use)||Svgcoat belts only (no contact to coater chuck or hotplate)||Svgcoat belts only, then SRD||YES oven use w/ teflon cassette||Station 1 in svgcoat2 (HMDS), but no coat, bake, or SRD|
|Normalized particle count||1.00||0.21-0.28||0.01-0.07||0.12-0.22||0.08-0.11||0.01-0.06||0.16-0.23|
In the above table, ranges indicate different sized particles measured and/or multiple wafers. Particle size ranges incorporated into each table entry correspond to the larger ones measureable with the particle counter, 24-256 um & 48-1024 um, as larger particles are most pertinent to the hotspot problem.