Disclosed herein are a method of forming stacked elongated nanoshapes (NSs) (e.g., stacked nanowires (NWs)) of different semiconductor materials above a substrate, a method of forming different devices (e.g., stacked field effect transistors (FETs) having different type conductivities) using the stacked NSs and the resulting structures. In the methods, stacked elongated NSs made of the same first semiconductor material can be formed above a substrate. The stacked elongated NSs can include at least a first NS and a second NS above the first NS. The second NS can then be selectively processed in order to convert the second NS from the first semiconductor material to a second semiconductor material. The first and second NSs can subsequently be used to form first and second devices, respectively, wherein the second device is stacked above the first device. The first and second device can be, for example, first and second FETs, respectively.