A semiconductor structure comprising at least one metal-oxide-semiconductor field-effect transistor (MOSFET) power device, the semiconductor structure comprising: a first insulating layer formed on a substrate; an active layer formed on at least a portion of the first insulating layer; a buried well having a first conductivity type formed in the active layer; a source region having a second conductivity type formed in the active layer proximate an upper surface of the active layer, the source region being electrically connected to the buried well; a drain region having the second conductivity type formed in the active layer proximate the upper surface of the active layer and spaced laterally from the source region; a body region having the first conductivity type formed in the active layer between the source and drain regions on at least a portion of the buried well, wherein the buried well has a higher doping level than the body region, at least a portion of the source region extends laterally into the body region, and the drain region comprises a lightly doped drain extension region extending from the body region; a background doping region of the active layer between the lightly doped drain extension region and the buried well, wherein the background doping region has the second conductivity type and a lower doping level than the lightly doped drain extension region; a gate formed above the active layer proximate the upper surface of the active layer and at least partially between the source and drain regions, the gate being electrically isolated from the active layer by a gate insulating layer; a drain terminal formed on the upper surface of the active layer and electrically connecting with the drain region; a source terminal electrically connecting with the source region; a gate terminal electrically connecting with the gate; and a shielding structure formed proximate the upper surface of the active layer between the gate and the drain region, the shielding structure comprising a field plate configured to control an electric field distribution along a top oxide interface away from an edge of the gate nearest the drain terminal, the buried well being configured with the higher doping level than the body region, in conjunction with the active layer, to form a clamping diode operative to position a breakdown avalanche region between the buried well and the drain terminal away from the gate insulating layer, a breakdown voltage of the at least one MOSFET power device being a function of one or more characteristics of the buried well. a first insulating layer formed on a substrate; an active layer formed on at least a portion of the first insulating layer; a buried well having a first conductivity type formed in the active layer; a source region having a second conductivity type formed in the active layer proximate an upper surface of the active layer, the source region being electrically connected to the buried well; a drain region having the second conductivity type formed in the active layer proximate the upper surface of the active layer and spaced laterally from the source region; a body region having the first conductivity type formed in the active layer between the source and drain regions on at least a portion of the buried well, wherein the buried well has a higher doping level than the body region, at least a portion of the source region extends laterally into the body region, and the drain region comprises a lightly doped drain extension region extending from the body region; a background doping region of the active layer between the lightly doped drain extension region and the buried well, wherein the background doping region has the second conductivity type and a lower doping level than the lightly doped drain extension region; a gate formed above the active layer proximate the upper surface of the active layer and at least partially between the source and drain regions, the gate being electrically isolated from the active layer by a gate insulating layer; a drain terminal formed on the upper surface of the active layer and electrically connecting with the drain region; a source terminal electrically connecting with the source region; a gate terminal electrically connecting with the gate; and a shielding structure formed proximate the upper surface of the active layer between the gate and the drain region, the shielding structure comprising a field plate configured to control an electric field distribution along a top oxide interface away from an edge of the gate nearest the drain terminal, the buried well being configured with the higher doping level than the body region, in conjunction with the active layer, to form a clamping diode operative to position a breakdown avalanche region between the buried well and the drain terminal away from the gate insulating layer, a breakdown voltage of the at least one MOSFET power device being a function of one or more characteristics of the buried well.