Abstract: In 1992, we began development of SiC membranes for X-ray masks using a prototype LPCVD system. A production type LPCVD system had been newly designed to provide significant improvements in film uniformity and achieved high productivity. SiC films of 2 micrometer in thickness produced by the new system showed uniform thickness distribution of plus or minus 0.6% in an area of 50 mm in diameter, and uniform stress of plus or minus 1% in an area of 25 mm square. SiC films in the suitable stress range of 100 to 350 MPa in tensile, with excellent thickness repeatability of plus or minus 0.06 micrometer, have been produced by the optimized process. SiC membrane of 3 micrometer in thickness, which are more effective for obtaining precise masks, showed uniformity similar to the membrane of 2 micrometer in thickness.!6
展开▼
