Investigation of MoSi Etch Processes for Embedded Attenuating Phase Shift Mask Applications Utilizing a Next Generation ICP Source

摘要

As critical dimensions and exposure wavelengths approach the physical limitations of optical lithography, the use of newer techniques such as Embedded Attenuating Phase Shift Masks become necessary to extend the viability of DUV lithographic tools. One of the more common EAPSM materials is MoSi and its analogues. Current MoSi processes are challenged to meet future requirements of improved CD and phase uniformity, vertical profiles, and reduced Quartz substrate damage. To this end, a Next Generation ICP (Inductively Coupled Plasma) hardware configuration has been adopted with improved plasma uniformity and larger process window. In this article, a description and a performance characterization of this new ICP source and Chamber Fixturing Hardware is presented. Additionally, the MoSi plasma etch parameter space is explored utilizing Design of Experiments and preliminary process optimization is offered. Finally, process results including etch rate uniformity, CD uniformity, and sidewall profiles are discussed.