<p>A thin-film semiconductor element is formed on a plastic substrate in a semiconductor device. A thermal expansion buffer layer is interposed between the thin-film semiconductor element and the plastic substrate. Although the thin-film semiconductor element is made from a material with a thermal expansion coefficient differing from the thermal expansion coefficient of the plastic substrate, the thermal expansion buffer layer interposed between the thin-film semiconductor element, and the plastic substrate protects the thin-film semiconductor element from damage caused by mechanical stress in the device fabrication process due to the different thermal expansion coefficients, enabling the semiconductor device to function reliably.</p>
