Smart mask ship to control for enhanced on wafer CD performance

Abstract

In the process of semicondutcor fabrication the translation of the final product requirements into specific targets for each component of the manufacturing process is one of the most demanding tasks. This involves the careful assessment of the error budgets of each component as well as the sensible balancing of the costs implied by the requirements. Photolithographic masks play a pivotal role in the semiconductor fabrication. This attributes a crucial role to mask error budgeting within the overall wafer production process. Masks with borderline performance with respect to the wafer fabrication requirements have a detrimental effect on the wafer process window thus inducing delays and costs. However, prohibitively strict mask specifications will induce large costs and delays in the mask manufacturing process. Thus setting smart control mechanisms for mask quality assessment is highly relevant for an efficient production flow. To this end GLOBALFOUNDRIES and the AMTC have set up a new mask specification check to enable a smart ship to control process for mask manufacturing. Within this process the mask CD distribution is checked as to whether it is commensurable with the advanced dose control capabilities of the stepper in the wafer factory. If this is the case, masks with borderline CD performance will be usable within the manufacturing process as the signatures can be compensated. In this paper we give a detailed explanation of the smart ship control approach with its implications for mask quality.