Transistor with a primary gate wrapping a floating secondary gate

Abstract

Disclosed is a structure including a substrate and a transistor on the substrate. The transistor includes a barrier layer above the substrate and a multi-gate structure on the barrier layer. The multi-gate structure includes a primary gate and a secondary gate. The secondary gate has opposing sidewalls, opposing end walls and a top surface. The primary gate includes essentially vertically-oriented first portions on the barrier layer positioned laterally adjacent to opposing sidewalls, respectively, of the secondary gate. Optionally, the primary gate also includes an essentially horizontally-oriented second portion on the top surface of the secondary gate and/or essentially vertically-oriented third portions on the opposing end walls, respectively. The secondary gate can be a floating gate. Also disclosed is a method of forming the structure.