Precise x-ray mask writing technology using advanced 100-kV EB writer EB-X3

Key issues of x-ray mask fabrication are EB mask writer and writing process on thin membrane. This paper shows precise x-ray mask writing technology using 100-kV EB writer on x- ray membrane mask. After several improvements of writing process including non-deformation mask holding and precise temperature control, absolute image placement accuracy within 10nm was obtained for giga-bit level ULSI pattern. Also the delineation characteristics of membrane mask writing using high-energy electron-beam including proximity effect and fogging effect were evaluated. Then accurate critical dimension control within 8 nm was achieved for such high density ULSI patterns. These good results satisfied the mask precision requirements for 100-nm node generation and below. So we fabricated precise x-ray masks having fine patterns of sub 100-nm node device for evaluation of advanced x-ray stepper.