Patent ID: 8492226

Claim:
A method of forming a device comprising: providing a substrate defined with a device region; forming a buried doped region in the substrate in the device region; forming a trench having upper and lower portions of different widths in the substrate in the device region; forming sidewall spacers on sidewalls of the upper portion of the trench, leaving a portion of the upper portion unfilled; forming a drain connector in the trench; removing the sidewall spacers, the removal of the sidewall spacer leaves a gap between the sidewalls of the trench and exposes a portion of the drain connector; forming a gate in the upper portion of the trench in the substrate in the device region, wherein a channel of the device is disposed on a sidewall of the upper portion of the trench, the buried doped region is disposed below the gate, wherein a distance from the buried doped region to the channel is a drift length L D of the device, wherein forming the gate comprises forming gate insulator layer on the exposed portion of the drain connector, and forming gate electrodes on either side of the gate insulators in the upper portion of the trench; and forming a surface doped region adjacent to the gate.