MnGe nanopattered DMS materials for Spintronics Nanoscale Devices Dilute Magnetic Semiconductor (DMS) have attracted a great deal of interest in recent years as they promise the possibility of combining the advantage of semiconductor bandgap engineering with controllable magnetic properties in a single semiconductor device. A particularly exciting development is the recent realization of ferromagnetism in Mn-doped group IV being attributed to their potential compatibility with current Si-based technology and expected high Curie temperature. In our group, we have focused our attention onto MnxGe1-x/Ge nanostructure composite films. We fabricated a novel periodic nanostructured MnxGe1-x by patterned assisted Mn implantation into Ge(111). The process flow is shown in Figure 1. To test electrical field controlled ferromagnetism, we fabricated a spin gated MOS structure using this MnxGe1-x nanostructures. Firstly we grew a thin Ge cap on top of this layer, and then employed Atomic Layer Deposition (ALD) to grow Al2O3 as the gate oxide. After the gate oxide deposition, the gate and the substrate were metallized with Al. A magnetic phase transition is able to turn the hole-induced ferromagnetism on and off by controlling the carrier concentration in DMS channel through gate bias, as shown in Figure 2. The results show the potential to realize a Spin Gain Transistor operating at room temperature, and further open the possibility for the development of novel spintronic devices.