A monolithic semiconductor device has a substrate with a power region and control region. The substrate can be a silicon-on-insulator substrate. An opening is formed in the power region and extends partially through the substrate. A semiconductor material is formed within the opening. A power semiconductor device, such as a vertical power transistor, is formed within the semiconductor material. A control logic circuit is formed in the control region. A first isolation trench is formed in the power region to isolate the power semiconductor device and control logic circuit. A second isolation trench is formed in the control region to isolate a first control logic circuit from a second control logic circuit. An interconnect structure is formed over the power region and control region to provide electrical interconnect between the control logic circuit and power semiconductor device. A termination trench is formed in the power region.