Analysis of thermal stress and transitory deformations in the SiC-W mask irradiated with a laser-created X-ray source

With a view to optimising the fabrication process for X-ray masks, this paper studies their deformation under irradiation. Over the last years this has become a problem of major importance in microelectronics. The heating of the mask during exposure to X-rays is critical since it can cause displacements and mechanical breaks due to the strain induced in the diaphragm and absorber. X-ray lithography has the potential for engraving patterns with dimensions smaller than 0.1 μm with only one level of resin. Hence the patterns on masks are of submicron size (1:1 ratio), which demands rigorous monitoring of deformations in the mask. These could restrict the use of X-ray masks in production. It is therefore necessary to estimate, simulate and limit the deformations