| 摘要 |
PROBLEM TO BE SOLVED: To obtain a stack of subsurface FETs of bulk single-crystal silicon, wherein all the FETs are formed simultaneously and a low-resistance capacitance for the source or darn is provided by providing a constitution such that an electronic device has parts neighboring the horizontal trench in a single- crystal substrate. SOLUTION: This device consists of a bulk single-crystal substrate 120, a horizontal trench 334 embedded in the single-crystal substrate 120 and electronic devices 182 and 186, having parts located in the bulk single-crystal substrate 120. For example, the horizontal trench 334 is formed by using doping-dependent porous silicon etching, and a gate insulating layer 160 and a gate conductor 162 are formed in the inside. Then, a boron-doped glass layer 174 is formed on the sidewall of a vertical trench 172. After n-type dopant ions have been implanted in the bottom part of the vertical trench, annealing is performed, and a p-channel transistor 186 and an n-channel transistor 182 are formed. |
