Method of forming a deep trench capacitor are provided. The method may include forming a deep trench in a substrate; enlarging a width of a lower portion of the deep trench to be wider than a width of the rest of the deep trench; epitaxially forming a compressive stress layer in the lower portion of the deep trench; forming a metal-insulator-metal (MIM) stack within the lower portion of the deep trench; and filling a remaining portion of the deep trench with a semiconductor. Alternatively to forming the compressive stress layer or in addition thereto, a silicide may be formed by co-deposition of a refractory metal and silicon.