A vertical centrifugal pump comprises a housing, impeller, annular guiding vanes, annular outlet with outer and inner casings, forming a collector with a pressure pipe, and flow channels to lower and upper rims. The gate and first terminals of the two capacitors preferably share the same conductive line such as a polysilicon segment. A first partial trench is formed in the second silicon layer between at least a portion of the gate region and at least a portion of the source region, wherein the first partial trench stops short of the insulator layer. A top of the base has a pair of connecting walls.