Influence of SOI wafer stress properties on placement accuracy of stencil masks

Summary form only given. Due to the high contrast and nearly lossless transmission, stencil masks offer important advantages over conventional optical masks. However, especially the issue of placement control has proven to be one of the key challenges of stencil mask technology. A high placement accuracy can only be achieved with a precise control of mechanical stress of each mask layer on a global and local scale. For this reason, the stress properties of the mask blank material - typically SOI wafers - have to be known and adjusted properly. In this paper a systematic investigation of initial stress properties and the resulting placement accuracy has been performed.