Isolation of circuit elements using front side deep trench etch

A method of forming an integrated circuit, the method comprising:

• providing a substrate comprising semiconductor material;
• forming components at a top surface of the substrate;
• forming an interconnect region over the substrate, comprising forming dielectric layers and forming interconnects in the dielectric layers;
• forming an isolation trench through at least a portion of the interconnect region and into the substrate at least 40 microns deep, so that at least 200 microns of substrate material remains in the substrate under the isolation trench, the portion of the interconnect region containing at least a portion of the interconnects;
• and
• forming dielectric material in the isolation trench to form an isolation structure, the dielectric material filling the isolation trench and contacting the substrate and the interconnect region, the dielectric material of the isolation structure separating an isolated region in the interconnect region of the integrated circuit from at least a portion of the substrate, the isolated region containing an isolated component of the integrated circuit above the isolation structure, the isolated component being electrically coupled to at least one of the components at the top surface of the substrate through the portion of the interconnects of the portion of the interconnect region.