The present disclosure relates to a high voltage transistor device having a field structure that includes at least one conduction unit, and a method of formation. In some embodiments, the high voltage transistor device has a gate electrode disposed over a substrate between a source region and a drain region located within the substrate. A dielectric layer laterally extends from over the gate electrode to over a drift region between the gate electrode and the drain region. A field structure is located within the first ILD layer. The field structure includes a conduction unit having a vertically elongated shape and vertically extending from a top surface of the dielectric layer and a top surface of the first ILD layer.