A substrate including a stack of a handle substrate, an optional lower insulator layer, a doped polycrystalline semiconductor layer, an upper insulator layer, and a top semiconductor layer is provided. A deep trench is formed through the top semiconductor layer, the upper insulator layer, and the doped polycrystalline semiconductor layer. Exposed vertical surfaces of the polycrystalline semiconductor layer are crystallographically etched to form random facets in the deep trench, thereby increasing the total exposed surface area of the polycrystalline semiconductor layer in the deep trench. A node dielectric and at least one conductive material are deposited to fill the trench and to form a buried strap portion, which constitute a capacitor of an eDRAM. Access transistors and other logic devices can be formed.