ESD damage in reticles used to be infrequent and easily detected. Now, due to the constantly shrinking feature sizes on reticles the damage mechanism has changed to a more subtle and continuous degradation mechanism - EFM.

Microtome first characterized this unusual reticle damage mechanism in 2003 and we have recently quantified it through pioneering research in conjunction with the University of Colorado at Colorado Springs*.

EFM is the field-induced migration of chrome and it can change the CD of a reticle by more than 6nm per second. It is very difficult to detect and a damaged reticle can be used for weeks before the defective products it has printed start to fail in final inspection. By that time, the production pipeline is full of defective inventory, which can cost millions of dollars in lost output.

EFM can be prevented, but the traditional ESD prevention techniques currently used in fabs are not sufficient and some "best practices" that are intended to protect against ESD - such as grounding reticles through static dissipative supports during handling - actually make the risk of field induced damage worse!

The most widely-used reticle SMIF pods and cassettes plus some of the most advanced pieces of reticle handling equipment in the industry adopt this grounding principle, but far from being protective as intended, they are inadvertently putting your reticles at an increased risk of electrostatic damage!

Such is the poor state of understanding of this problem in the semiconductor industry today.

You may be working in one of the fabs where millions of dollars have been spent on ESD protection and - if you are lucky enough not to have a reticle electrostatic damage problem now - you may conclude that the problem is being adequately managed. Yet the absence of reticle ESD damage is no more an indication that the risk is being properly managed than crossing a road without looking and not being knocked down is proof that it is safe to do so. It is necessary to fully understand a risk before it is possible to conduct a valid risk assessment.

We know that getting the basics wrong has cost one of the most advanced fabs in the world millions of dollars in lost output - we have seen it for ourselves. Can you take the risk that this serious problem is not properly understood in your company?

This is why our expertise in this area is so valuable to you - we have the necessary knowledge in depth and we can draw your technicians' attention to some potentially costly misunderstandings about reticle electrostatic protection (e.g. reticle grounding).

So, whether your interest is simply in updating the education of your reticle handling staff to include awareness about EFM, or in having a facility-wide reticle safety check to help you identify areas of your operation that might expose your reticles to invisible electrostatic risk, we are able to help you.