Investigation of stress-induced (100) platelet formation and surface exfoliation in plasma hydrogenated Si

We have studied the mechanisms underlying stress-induced platelet formation during plasma hydrogenation. The stress is purposely introduced by a buried SiGe stained layer in a Si substrate. During plasma hydrogenation, diffusing H is trapped in the region of the SiGe layer and H platelets are formed. The platelet orientation is controlled by the in-plane compressive stress, which favors nucleation and growth of platelets in the plane of stress and parallel to the substrate surface, and ultimately leads to controlled fracture along the SiGe layer. Also, the SiSiGeSi structure is found to be more efficient in utilizing H for platelet formation and growth compared to H ion implanted Si because there are fewer defects to trap H (e.g., Vn Hm and In Hm); therefore, the total H dose needed for layer exfoliation is greatly reduced.