Conducting layers for charged particle beam projection lithography masks
Original Publication Date: 2000-Nov-01
Included in the Prior Art Database: 2003-Jun-18
Conducting layers for charged particle beam projection lithography masks Stencil masks are advantageously fabricated using diamond as the membrane material as described in a previous disclosure now filed with the US Patent Office. However, during the fabrication of these masks, issues with the diamond film being an electrical insulator have been discovered during mask processing. This causes difficulties both during mask fabrication and during use as a charged particle beam mask. Typical stencil masks are made from silicon membranes that are electrically conducting, but diamond provides advantages for stiffness and thermal conductivity. Charging phenomena have been observed during e-beam write and SEM inspection with a typical diamond stencil mask process. The stack in this case was diamond with a dielectric hardmask and photoresist (all insulating layers). This idea describes the use of thin discharge layers on the diamond membranes. The layers would be added at the beginning of the mask. The discharge layers could be thin metal layers or, more preferably for diamond, thin graphite layers formed by changing the deposition conditions during the diamond deposition or by modifying surface of the diamond layer after deposition.