Stress-Compensating Structure for Silicon Carbide Thin Films
Original Publication Date: 1988-Sep-01
Included in the Prior Art Database: 2005-Feb-15
A technique is described whereby silicon carbide thin films, grown under high tensile stress as used in X-ray lithography mask membranes, are structured and fabricated such that the stress can be partially compensated and tailored to an optimum value. The resulting thin film will, therefore, increase the effective strength and life of the membrane. SiC thin films, when grown on silicon substrates, are typically highly stressed films under tension. However, excessive tension is detrimental for its effective strength since any applied stress will be in addition to the grown-in. Grown-in stress is the stress under which the film is found after growth. It exists in the absence of any externally applied stress. Nucleation and growth processes and differential thermal expansion are responsible for the grown-in stress.