A method is described what includes providing a substrate having a first trench and a second trench. An epitaxy material (crystalline material) is formed in the first trench and in the second trench. The top surface of the epitaxy material in the first trench is noncollinear with a top surface of the epitaxy material in the second trench. An amorphous semiconductor layer is formed on the crystalline material. Subsequently, the amorphous layer is converted, in part or in whole, into the crystalline semiconductor material. In an embodiment, a planarization process after the conversion provides crystalline regions having a coplanar top surface.