Self-Assembled Si Quantum-Ring Structures on a Si Substrate by Plasma-Enhanced Chemical Vapor Deposition Based on a Growth-Etching Competition Mechanism

摘要

We have, for the first time, fabricated self-assembled Si quantum-ring structures on a Si substrate by using a PECVD technique based on a plasma growth/etching competi- tion mechanism. We obtained perfect Si quantum rings with excellent rotational symmetry and a narrow edge width (down to 10 nm). Moreover, the ring size and morphology were tuned by simply adjusting the timing procedure, and the fabrication process was fully compatible with standard microelectronic Si technologies. The as-grown Si ring structures could be electrically well isolated by controlling the ring/substrate junction bias condition, which lays the ground work for further device applications. We also suggest that this growth model, because it is not limited to certain specific material systems, actually represents a general scheme for controlling and tailoring the shapes, sizes, and complexities of self-assembled nanostructures.