A vertical power device, comprising: a semiconductor substrate having first and second trenches and a drift region of a first conductivity type therein that extends into a mesa defined by the first and second trenches; first and second insulated electrodes in the first and second trenches; first and second base regions of a second conductivity type that extend adjacent sidewalls of the first and second trenches, respectively, and in the mesa; first and second source regions of the first conductivity type in said first and second base regions, respectively; an insulated gate electrode that extends on a surface of said semiconductor substrate and opposite said first and second base regions; and a source electrode over the surface of said semiconductor substrate and electrically connected to the first and second insulated electrodes in the first and second trenches and to the first and second source regions; and a first shielding region of the second conductivity type that extends between said first base region and the drift region and is more highly doped than said first base region; and a second shielding region of the second conductivity type that extends between said second base region and the drift region and is more highly doped than said second base region; wherein said first and second shielding regions extend adjacent sidewalls of the first and second trenches, respectively; and a transition region of the first conductivity type in the upper portion of the drift region, wherein the transition region extends between said first and second base regions and between said first and second shielding regions, wherein said transition region forms a non-rectifying junction with the drift region and has a vertically retrograded first conductivity type doping profile with a dopant concentration that peaks at a first depth relative to the surface. a semiconductor substrate having first and second trenches and a drift region of a first conductivity type therein that extends into a mesa defined by the first and second trenches; first and second insulated electrodes in the first and second trenches; first and second base regions of a second conductivity type that extend adjacent sidewalls of the first and second trenches, respectively, and in the mesa; first and second source regions of the first conductivity type in said first and second base regions, respectively; an insulated gate electrode that extends on a surface of said semiconductor substrate and opposite said first and second base regions; and a source electrode over the surface of said semiconductor substrate and electrically connected to the first and second insulated electrodes in the first and second trenches and to the first and second source regions; and a first shielding region of the second conductivity type that extends between said first base region and the drift region and is more highly doped than said first base region; and a second shielding region of the second conductivity type that extends between said second base region and the drift region and is more highly doped than said second base region; wherein said first and second shielding regions extend adjacent sidewalls of the first and second trenches, respectively; and a transition region of the first conductivity type in the upper portion of the drift region, wherein the transition region extends between said first and second base regions and between said first and second shielding regions, wherein said transition region forms a non-rectifying junction with the drift region and has a vertically retrograded first conductivity type doping profile with a dopant concentration that peaks at a first depth relative to the surface.