RELEASED GROUP IV CHANNEL BODY OVER DISTINCT GROUP IV SUB-FIN

摘要

An integrated circuit structure includes a channel body including a first group IV semiconductor material (e.g., Si_1-xGe_x, where 0.2 ≤ x ≤ 1.0), and a sub-fin below the channel body, the sub-fin including a second group IV semiconductor material (e.g., Si) different from the first group IV semiconductor material. A gap is formed between the channel body and the sub-fin, and an intervening layer of insulator material is disposed in the gap, the intervening layer in contact with at least the top of the sub-fin. Trench isolation is in contact with lower sidewalls of the sub-fin. In some cases, the intervening layer is also in contact with upper sidewalls of the sub-fin that are not in contact with the trench isolation. The intervening layer may be provided by the gate dielectric and electrode materials, or by a distinct insulator material. Double-gate, tri-gate, and gate-all-around transistor structures are provided.