A method for manufacturing a semiconductor device includes forming a first semiconductor layer on a semiconductor substrate, forming a second semiconductor layer including a first concentration of germanium on the first semiconductor layer, and forming a third semiconductor layer on the second semiconductor layer. The first and third semiconductor layers each have a concentration of germanium, which is greater than the first concentration of germanium. The first, second and third semiconductor layers are patterned into at least one fin. The method further includes covering the second semiconductor layer with a mask layer. In the method, a bottom source/drain region and a top source/drain region are simultaneously grown from the first semiconductor layer and the third semiconductor layer, respectively. The mask layer is removed from the second semiconductor layer, and a gate structure is formed on and around the second semiconductor layer.