Skip to content. | Skip to navigation

Sections
Personal tools
You are here: Home / Equipment / Optical Photolithography Overview / Exposure Tool Summary / ASML / ASML Community / Follow-up: May 2011 Community Meeting Action Items

Follow-up: May 2011 Community Meeting Action Items

This document describes the follow-up to the action items derived at the May 11, 2011 ASML community meeting.

The action items from the May 11, 2011 community meeting are largely taken care of. Therefore, the next meeting will be scheduled on an as-needed basis. Please communicate with staff if there are needs not being met with the ASML and we can determine together if they need to be addressed at the community level.

 

Please review the rest of this document to understand the status of the action items from the May 2011 ASML community meeting.

 

For review, the list of action items from the May 11, 2011 community meeting were as follows:

Items being worked on or for review at a subsequent meeting:

  • A 3-strikes punishment policy including either a user-done particle check or a user-done hotspot check. (Revisit)
  • Particle counts from SRD-only, oven-only, cassette-use-only, flatness table-only, and N2-gun-blown-only. (WIP)
  • Determine if hotspot test works on test wafers with 955 or 1um 3612. (WIP)
  • Put litho SRD on Coral. (Revisit)
  • Determine "expired" user requalification policy. (Revisit)

 

How these action items have been addressed is as follows:

  • "Punishment policy of user-done particle or hotspot check"

Final word:

Given that there have been no complaints about punishment policies since the community meeting, policy will remain as-is. Labmembers, please make concerns known to the litho team if this isn't meeting needs.

Other details:

The "user-done hotspot check" as punishment isn't as feasible as hoped. The hotspot check done on stockroom wafers proved to not conclusively show hotspots. See Mahnaz if further details are needed.

The main stumbling block for a "user-done particle check" as punishment is it would require training of ASML users in fault of policy on the particle counter. This is still potentially a possibility, but the decision on a new punishment policy above negates the need for something like this for now.

 

  • "Additional particle counts"

Final word:

 The choice of using the SRD after anything relating to the svg tracks has been wise.

As reported at the meeting, 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.  The last few months' reports of particles on the chuck after enforcing this policy also speaks clearly about the improvement.

Other 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.

 

  • "Hotspot test on stockroom wafers"

The "user-done hotspot check" as punishment isn't as feasible as hoped. The hotspot check done on stockroom wafers proved to not conclusively show hotspots. See Mahnaz if further details are needed.

 

  • "Litho SRD on Coral"

Users, in general, seem to be abiding by the SRD post-coater track rule and therefore this is now low priority. Please report to the litho team if you see cases where having had a Coral enable on this SRD would have prevented ASML tool problems.

 

  • "'Expired' user requalification policy"

This item has not been given attention. Please report to the litho team if there are cases where users out of touch with machine use and policy are endangering the tool so we can determine how pressing the need for such a policy is.

 

 

Document Actions