Anna Tchikoulaeva GLOBALFOUNDRIES Dresden Module Two GmbH & Co KG (Germany) Remo Kirsch GLOBALFOUNDRIES Dresden Module One LLC & Co. KG (Germany) Stephanie Winkelmeier Advanced Mask Technology Ctr. GmbH & Co. KG (Germany)
Reticle defectivity has been a widely discussed topic in the last few years primarily due to
ongoing haze issues but also because of the increasing number of the qualification methods
available in the fab. Mask shops are taking a closer look at the alternatives to the direct reticle
inspection , making a step towards wafer inspection as a valid option for reticle qualification.
High MEEF patterns represent the most interesting and challenging case study due to potentially
comparable sensitivity performance of the wafer inspection and reticle inspection tools as
reported in . A reticle with programmed defects in different environments was used to define
detection limits, capture rates and noise levels for both direct reticle inspection and the inspection
of the wafer print. Reticle inspection was performed using KLA587 tool. For the inspection of
the wafer prints two most advanced DUV inspection tools were used. Defect sizes were defined
on the reticle and on the wafer using SEM CD tools.
The focus of this study was to identify gaps and opportunities existing in the reticle qualification
chain starting with the outgoing qualification at the mask shop and continuing during the reticle
lifetime in the fab. Results and conclusions of this investigation will be presented and discussed
in conjunction with the prospects and possible modifications of pursued approach for 45nm and
the future nodes.