A semiconductor device design method useful for the design of microprocessor, ASIC, and high-speed high-performance LSI is intended to enhance the accuracy of delay calculation and crosstalk noise calculation, and enhance the accuracy of assessment of delay variation caused by crosstalk and checking of malfunctioning caused by crosstalk. The mask has a nasal cushion forming a nose-receiving cavity. The shadow memory device includes a non-volatile nanotube switch that stores the corresponding state of the shadow device. Other embodiments are claimed and disclosed.