Patent ID: 8883634

Claim:
A method for forming a device comprising: providing a semiconductor substrate having first and second major surfaces, the substrate includes first and second isolation trenches disposed on the first major surface in first and second substrate regions of the substrate, the isolation trenches extend partially through the substrate, wherein the trenches are filled with isolation material; removing the isolation material from the first isolation trench to form a first stress buffer trench while the isolation material remains in the second isolation trench to form an isolation region; filling the first stress buffer trench with a stress buffer material to form a stress buffer in the first substrate region; and forming a through silicon via (TSV) contact in the first substrate region, the TSV contact has first and second portions, the second portion extends beyond a bottom of the stress buffer, wherein the stress buffer completely surrounds the first portion of the TSV contact and alleviates stress created by the difference in coefficient of thermal expansion (CTE) between the TSV contact and the semiconductor substrate.