Silicon-on-insulator structure and method of reducing backside drain-induced barrier lowering

A method, comprising:

• on a semiconductive layer of a substrate, forming a gate stack including a spacer, the semiconductive layer overlying an insulator layer and the insulator layer overlying the substrate;
• by a gate stack self-aligned etch, forming a recess through the semiconductive layer and through the insulator layer below the semiconductive layer;
• forming an inside contact beneath the semiconductive layer in the recess that is self-aligned along one side thereof with the first spacer, the inside contact to intercept and drain electromagnetic energy from the semiconductive layer;
• and
• forming an outside contact in the recess that is spaced apart and opposite the inside contact.

A method, comprising:

• forming a gate stack including a first spacer on a semiconductive layer, the semiconductive layer overlying an insulator layer and the insulator layer overlying a silicon substrate;
• performing a first etch, self-aligned with the gate stack, entirely through the semiconductive layer and into a portion of the insulator layer, the insulator layer etched to a small distance beneath a bottom extremity of the semiconductive layer;
• forming a second spacer at the gate stack, the second spacer formed along the entire side length of, and below, the first spacer so that a bottom end of the second spacer bottoms out on the etched insulator layer;
• performing a second etch that penetrates through the insulator layer to a top surface of the underlying substrate to form an undercut beneath the second spacer, the undercut extending from the bottom end of the second spacer to the top surface of the substrate;
• depositing a conductive film over the gate stack, over the first and second spacers, over the top surface of the substrate, and within the undercut;
• and
• performing a third etch in alignment with an outside edge of the second spacer, the third etch removing the conductive film from over the gate stack, from over the first and second spacers and from over the substrate, the second spacer protecting the conductive film from being etched within the undercut thus forming a vertically oriented conductor at the undercut beneath the semiconductive layer, the vertically oriented conductor having a bottom end that connects to the surface of the substrate and a top end that terminates said small distance from the bottom extremity of the semiconductive layer so as not to connect with the semiconductive layer, the vertically oriented conductor to intercept and drain electromagnetic energy away from the semiconductive layer.