Inter-poly dielectric in a shielded gate mosfet device

An apparatus, comprising:

• a shield dielectric disposed within a trench aligned along an axis within an epitaxial layer of a semiconductor;
• a shield electrode disposed within the shield dielectric and aligned along the axis;
• a first inter-poly dielectric having a portion defining a ring aligned along a plane intersecting the shield electrode, the plane being orthogonal to the axis;
• a second inter-poly dielectric having a portion disposed between the portion of the first inter-poly dielectric and the shield electrode;
• and
• a gate dielectric having a portion coupled to the first inter-poly dielectric.

An apparatus, comprising:

• a shield dielectric disposed within a trench within an epitaxial layer of a semiconductor;
• a shield electrode disposed within the shield dielectric;
• an inter-poly dielectric having a first portion coupled to the shield dielectric and a second portion coupled to the shield electrode, the inter-poly dielectric having a top surface defining a concave shape;
• and
• a gate dielectric having a portion disposed on the top surface of the inter-poly dielectric.

A method, comprising:

• forming a shield electrode within a shield dielectric disposed within a trench of an epitaxial layer of a semiconductor;
• removing a first portion of the shield dielectric disposed above the shield electrode so that a second portion of the shield dielectric remains coupled to a wall of the trench;
• and
• forming, within the trench, an inter-poly dielectric having a thickness along the second portion of the shield dielectric less than a combined thickness of the first portion of the shield dielectric and the second portion of the shield dielectric.