The fabrication of three-dimensional nanostructures is key to the development of next-generation nanoelectronic devices with a low device footprint. Magnetic racetrack memory encodes data in a series of magnetic domain walls that are moved by current pulses along magnetic nanowires. To date, most studies have focused on two-dimensional racetracks. Here we introduce a lift-off and transfer method to fabricate three-dimensional racetracks from freestanding magnetic heterostructures grown on a water-soluble sacrificial release layer. First, we create two-dimensional racetracks from freestanding films transferred onto sapphire substrates and show that they have nearly identical characteristics compared with the films before transfer. Second, we design three-dimensional racetracks by covering protrusions patterned on a sapphire wafer with freestanding magnetic heterostructures. We demonstrate current-induced domain-wall motion for synthetic antiferromagnetic three-dimensional racetracks with protrusions of up to 900 nm in height. Freestanding magnetic layers, as demonstrated here, may enable future spintronic devices with high packing density and low energy consumption.

三维纳米结构的制造是开发具有低器件足迹的下一代纳米电子器件的关键。磁跑道存储器将数据编码在一系列磁畴壁中，这些磁畴壁由电流脉冲沿磁性纳米线移动。迄今为止，大多数研究都集中在二维赛道上。在这里，我们介绍了一种剥离和转移方法，用于从在水溶性牺牲释放层上生长的独立磁性异质结构制造 3D 跑道。首先，我们从转移到蓝宝石基板上的独立薄膜创建二维跑道，并表明与转移前的薄膜相比，它们具有几乎相同的特性。第二，我们通过覆盖具有独立磁性异质结构的蓝宝石晶片上图案化的突起来设计 3D 跑道。我们展示了用于合成反铁磁三维跑道的电流引起的畴壁运动，其突起高度高达 900 nm。如此处所示，独立的磁性层可以使未来的自旋电子器件具有高封装密度和低能耗。