DT capacitor with silicide outer electrode and/or compressive stress layer, and related methods
Method of forming a deep trench capacitor are provided. The method may include forming a deep trench in a substrate; forming a metal-insulator-metal (MIM) stack within a portion of the deep trench, the MIM stack forming including forming an outer electrode by co-depositing a refractory metal and silicon into the deep trench; and filling a remaining portion of the deep trench with a semiconductor.
1. A method of forming a deep trench capacitor, the method comprising:
forming a deep trench in a substrate;
forming a metal-insulator-metal (MIM) stack within a portion of the deep trench, the MIM stack forming including forming an outer electrode by co-depositing a refractory metal and silicon into the deep trench,
wherein the co-depositing of the refractory metal and the silicon includes alternately depositing the refractory metal and the silicon into the deep trench; and
filling a remaining portion of the deep trench with a semiconductor.
2. The method of claim 1 , further comprising, prior to forming the MIM stack:
enlarging a width of a lower portion of the deep trench to be wider than a width of the rest of the deep trench; and
epitaxially forming a compressive stress layer in the lower portion of the deep trench.
3. The method of claim 2 , wherein the enlarging includes depositing an etch resistant layer over an upper portion of the deep trench, and performing a wet etch of the lower portion of the deep trench.
4. The method of claim 2 , wherein the compressive stress layer forming includes epitaxially growing silicon germanium on a surface of the lower portion of the deep trench.
5. The method of claim 4 , further comprising doping the silicon germanium with an n-type dopant.
6. The method of claim 1 , wherein the MIM stack forming further includes forming a node dielectric layer and an inner electrode layer over the outer electrode.
7. A method of forming a deep trench capacitor, the method comprising:
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 only in the lower portion of the deep trench directly against the substrate;
forming a metal-insulator-metal (MIM) stack within a portion of the deep trench, the MIM stack forming including forming an outer electrode by co-depositing a refractory metal and silicon into the deep trench;
wherein the co-depositing of the refractory metal and the silicon includes alternately depositing the refractory metal and the silicon into the deep trench; and
filling a remaining portion of the deep trench with a semiconductor.
8. The method of claim 7 , wherein the co-depositing of the refractory metal and the silicon includes alternately depositing the refractory metal and the silicon into the deep trench.