FLEXIBLE CRSS ADJUSTMENT IN A SGT MOSFET TO SMOOTH WAVEFORMS AND TO AVOID EMI IN DC-DC APPLICATION

摘要

A semiconductor power device comprises a plurality of power transistor cells each having a trenched gate disposed in a gate trench wherein the trenched gate comprising a shielding bottom electrode disposed in a bottom portion of the gate trench electrically insulated from a top gate electrode disposed in a top portion of the gate trench by an inter-electrode insulation layer. At least one of the transistor cells includes the shielding bottom electrode functioning as a source-connecting shielding bottom electrode electrically connected to a source electrode of the semiconductor power device and at least one of the transistor cells having the shielding bottom electrode functioning as a gate-connecting shielding bottom electrode electrically connected to a gate metal of the semiconductor power device.

主权项

1. A method for manufacturing a semiconductor power device comprising a source metal and a gate metal electrically connected to a source and gate of the semiconductor power device respectively , wherein the method comprising:
opening a plurality of trenches in a substrate and filling said trench with a conductive gate material; and applying a mask for carrying out a time etch for etching back said gate material from selected trenches, each adjacent to active transistor cells, thus leaving a bottom portion in said selected trenches and leaving the trenches covered by the mask still filled with the gate conductive material; covering the bottom portion in said selected trenches with a shielding insulation to form a bottom shielding electrode; designating some of the trenches still filled with the conductive gate material as source contact trenches for contacting the source metal and reminder of the trenches filled with the conductive gate material as gate contact trenches for contacting to the gate metal; and electrically contacting a first predetermined set of the bottom shielding electrodes to at least one of the source contact trench and a second predetermined set of the bottom shielding electrodes to at least one of the gate contact trenches.