STRESS OPTIMIZATION IN SIC FILMS FOR X-RAY-MASK MEMBRANE APPLICATION

One of the key factors for successful X-ray lithography is a well-established and controlled X-ray-mask technology. In this paper, we describe the development of a silicon carbide membrane for X-ray-mask applications. The most critical step is the generation of thin SiC films (approximately 2-mu-m of thickness) with a low tensile stress (< 1 x 10(9) dynes cm-2 or 1 x 10(8) Pa). For this purpose, the SiC films were prepared in a 100 kHz plasma-enhanced chemical vapor deposition system from a gas mixture of silane, methane, and argon on a Si substrate. The appropriate low tensile stress is then achieved by thermal annealing. Using this method, SiC membranes of 2.5 cm diameter were obtained.