摘要 |
<p>Crystal grains of a lower polysilicon layer is grown through an annealing or an ion-implantation before separation of the lower polysilicon layer into doped silicon pieces, an upper polysilicon layer with small crystal grains is deposited over the doped silicon pieces so as to wave at long intervals, and the upper polysilicon layer is roughened so as to wave at short intervals, thereby increasing the surface area of an accumulating electrode of a capacitor.</p> |