| 摘要 |
PURPOSE:To readily control the channel length of a semiconductor device by forming a gate electrode on the partial upper surface of a single crystal region and forming a source and a drain on a polycrystalline region and the single crystal region of both sides. CONSTITUTION:A polycrystalline silicon film 3 and a single crystal silicon film 4 are epitaxially grown on a single crystal silicon substrate 1, and a gate electrode 9 is formed on the partial upper surface of a single crystal silicon film 4. With the gate electrode 9 as a protective mask arsenic ions are injected, and source region 10 and drain region 11 are formed. Since the diffusion of the arsenic advances to the depth of several times the thickness of the polycrystalline region as compared with the single crystal region, the diffused layer becomes deep in the film 4, so that the resistance becomes small. Since the diffusion is shallow in the film 3 and lateral diffusion is small, it can prevent the reduction in the channel length. |
