Method of forming a recessed gate structure on a substrate having insulating columns and removing said insulating columns after forming a conductive region of the gate structure

A method of forming a transistor structure, the method comprising the acts of:

• forming a plurality of spaced insulating column structures over a substrate comprising semiconductor material and dielectric material, semiconductor material being exposed between a first adjacent pair of the spaced insulating column structures, dielectric material being exposed between a second adjacent pair of the spaced insulating column structures;
• forming an oxide layer over the exposed semiconductor material between the first adjacent pair of the spaced insulating column structures but not over the exposed dielectric material between the second adjacent pair of the spaced insulating column structures;
• after forming the oxide layer, etching through said oxide layer and forming at least one trench structure within semiconductor material of said substrate between the first adjacent pair of insulating column structures, said adjacent insulating column structures acting as a guide to form the trench;
• forming a first conductive region at least partially within said trench structure;
• forming a second conductive region above said first conductive region and electrically connected to said first conductive region;
• removing said insulating columns after forming the first and second conductive regions;
• and
• forming source and drain regions within semiconductor material of said substrate on respective sides of said first conductive region.

A method of forming a recessed gate structure, comprising the acts of:

• forming insulating columns directly on a top surface of a semiconductor substrate;
• after forming the insulating columns, forming a trench within said semiconductor substrate and adjacent said insulating columns, wherein a maximum width of said trench is less than a distance by which said insulating columns are spaced apart;
• forming a gate oxide on the bottom and sidewalls of said trench;
• forming polysilicon within the trench over the gate oxide;
• forming a metal layer within the trench over the polysilicon;
• after forming the metal layer, implanting a conductivity enhancing dopant into the polysilicon;
• and
• removing said insulating columns after forming the metal layer.