Patent attributes
A method for forming a shielded gate of a MOSFET includes steps as following: providing a semiconductor substrate having at least one trench, forming a bottom gate oxide region and a shielded gate poly region in the trench of the semiconductor substrate, forming an inter-poly oxide region on the shielded gate poly region through high temperature plasma deposition, poly etching back and oxide etching back; and forming a gate oxide region and a gate poly region on the inter-poly oxide region. By utilizing the etching back processes in replace of traditional chemical mechanical polishing processes, the manufacturing cost of manufacturing a shielded gate structure is reduced, and the total cost of manufacturing a FET is also reduced. Meanwhile, the gate charge is effectively reduced due to the shielded gate structure, so that the performance of a MOSFET is enhanced.
