Layered X-Ray Mask Substrate
Original Publication Date: 1985-Apr-01
Included in the Prior Art Database: 2005-Feb-18
A two-layer supporting membrane structure for an X-ray mask is described in which the bottom layer is boron-doped silicon and the top layer is either boron nitride or silicon carbide. The new X-ray substrate is a multilayer structure formed on a silicon wafer 10 bonded to a PYREX* ring 12, as shown in the figure. The fabrication process is as follows: (1) Boron dope a silicon wafer on one side to form a thin boron- doped silicon layer 14. (2) Deposit BN 16 or SiC on both sides. (3) Pattern the BN on the undoped side to define an exposure window 17 and alignment window 18. (4) Etch the BN on the undoped backside to form the window pattern. (5) Etch the Si on the undoped backside down to the doped layer to form the windows.