A semiconductor chip includes an active layer on a top surface of an underlying base substrate. The active layer has: bonding surface therein that delineates an interface between a bottom active layer and a top active layer extending on the bottom active layer, and a chamfered edge that extends entirely through the top active layer to fully expose a sidewall thereof but only partially through the bottom active layer, such that the chamfered edge has a vertical height greater than a thickness of the top active layer but less than a combined thickness of the top and bottom active layers. A protective layer is also provided, which covers at least a portion of a top surface of the active layer. A vertical level of a bottom of the chamfered edge may be higher than a vertical level of the top surface of the base substrate.