A method of forming a semiconductor structure is provided. The method includes providing a substrate with a first melting point. A sacrificial layer with a second melting point is forming over the substrate. The second melting point is less than the first melting point. A stack of semiconductor layers is formed over the sacrificial layer. The stack of semiconductor layers has a third melting point greater than the second melting point and a formation temperature less than the second melting point. A thermal process is performed at a temperature greater than the second melting point and less than the first melting point and the third melting point in order to melt the sacrificial layer such that the substrate is stripped from the stack of semiconductor layers.