US Patent 9530798 High performance heat shields with reduced capacitance

Methods and structures for capacitively isolating a heat shield from a handle wafer of a silicon-on-insulator substrate. A contact plug is located in a trench extending through a trench isolation region in a device layer of the silicon-on-insulator substrate and at least partially through a buried insulator layer of the silicon-on-insulator substrate. The heat shield is located in an interconnect structure, which also includes a wire coupling the heat shield with the contact plug. An isolation structure is positioned between the contact plug and a portion of the handle wafer. The isolation structure provides the capacitive isolation.