SWITCHING ELEMENT AND ITS MANUFACTURING METHOD AND SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD AND ELECTRO-OPTIC DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a switching element in which a variation in switching characteristics between transistors is very small and an occupancy area can be reduced significantly when mounted on a circuit board and not only a high breakdown voltage but also a prevention of electrical interference among transistors can be realized by using a substrate with high electrical insulation. SOLUTION: A single crystal silicon thin film 4 is grapho-epitaxial-grown by a catalyst CVD method on a glass substrate 1 having a step and single crystalline silicon TFTs Q1 -Qn are formed by patterning the single crystalline silicon thin film 4 into strap-shapes. A threshold voltage of the single crystal silicon TFTs Q1 -Qn is set to become larger sequentially. The single crystal silicon TFTs Q1 -Qn are switched sequentially by applying a saw-tooth shaped gate voltage to a common gate 8.