Creating and measuring photomask damage

Reticle damage due to electric fields has been demonstrated using the Canary^trade reticle[1]. This effect, called the Field Induced Model (FIM), was simulated using a stainless steel electrode which caused damage to the Canary^trade reticle. The FIM has now been demonstrated to cause damage to 0.25 mum technology-node reticles of a design that is in current production at a modern semiconductor fab. Damage was seen in metal layer, gate and via layer reticles. The greatest amount of damage was observed in the metal layers, characterized by relatively long structures. This is predicted for FIM damage. In this paper, the apparatus that was employed to damage the reticles is described. The methods for detecting the damage, both through an ESD-induced EMI signature, and reticle scanning, are presented.