An effective haze monitoring method

摘要

Monitoring and controlling of haze defect is becoming important more than ever before [1]. Regular and frequent maskinspection is expected to reduce the risk of defect print on wafer [2]. However, such frequent inspection requires longerinspection time and additional cost, which should lead to worsening of productivity. It is known that haze defect grows from non-killer defect at its infant stage to killer defect as time advances. And suchhaze growth process is dependent on the haze size in its infant stage, location of haze generation and such. If the hazeinspection procedure were customized in a most suited way to optimally monitor the growth characteristics of haze, theinspection throughput would become higher without sacrificing the performance and reliability of mask inspection itself. For such a purpose, we have studied an effective haze monitoring method that ensures both sensitivity and throughputhigh enough. We will show that a variable scan method using a DUV mask inspection tool is quite effective in cuttingdown inspection time and cost.