Patent ID: 7374974

Claim:
A method of manufacturing a semiconductor device having a substrate, the method comprising: forming a thyristor having at least a portion of the thyristor's body region in and formed from the substrate; forming a trench in the substrate adjacent to the at least one portion of the thyristor's body region; forming conductive filler material in the trench; forming a control port in the trench, the control port being configured and arranged to capacitively couple to the thyristor body region for controlling current flow therein; and forming a dielectric material in the trench to at least partially fill the trench and electrically insulates the conductive filler material from the control port; wherein forming the dielectric material in the trench includes thermally growing the dielectric material in the trench; and wherein thermally growing the dielectric material in the trench includes thermally growing the dielectric material on the conductive filler material at a first growth rate and thermally growing the dielectric material on a sidewall of the trench at a second growth rate, the first growth rate being higher than the second growth rate.