AI 中文总结
本研究制备了兼容BEOL的YPtBi/W/CoFeB异质结构，明确其SOT响应源于W掺入YPtBi上界面，为规模化SOT存储及存算一体硬件提供了可行自旋源材料路线。
AI 中文摘要
自旋轨道矩（SOT）器件需要兼具高效电荷-自旋转换能力与后端制程（BEOL）热兼容性的自旋源材料。本研究表明，直接沉积在Si/SiOx衬底上的YPtBi/W/CoFeB异质结构，在室温至400℃范围内仍保持主要为非晶或弱纳米晶状态，同时保留了显著的类阻尼有效SOT响应。反常霍尔效应、谐波霍尔测量，结合X射线衍射、横截面透射电子显微镜、X射线反射率及电子能量损失谱分析显示，该响应与YPtBi的体结晶无关；界面分析表明，自旋霍尔角的最强变化趋势与YPtBi/W上边界的化学性质相关，有效SOT响应随该YPtBi表面的W浓度积分值变化。同时，双自旋源分析显示，富Pt-W中间层仅提供微小的正修正，不足以单独解释大的负有效自旋霍尔角；因此推断，主要控制变量是W掺入YPtBi上界面，这可能改变YPtBi的局域电子结构并放大堆叠级响应。这些结果为堆叠行为提供了更具物理约束的解释，并确定了一条兼容BEOL的无序拓扑自旋源层制备路线，可用于规模化SOT存储器及存算一体硬件。
英文摘要
Spin-orbit torque (SOT) devices require spin-source materials that combine efficient charge-to-spin conversion with back-end-of-line (BEOL) thermal compatibility. Here, we show that YPtBi/W/CoFeB heterostructures deposited directly on Si/SiOx remain predominantly amorphous or weakly nanocrystalline from room temperature to 400 °C while preserving a large effective damping-like SOT response. Anomalous Hall and harmonic Hall measurements, together with X-ray diffraction, cross-sectional transmission electron microscopy, X-ray reflectivity, and electron energy-loss spectroscopy, show that the response does not correlate with bulk crystallization of YPtBi. Instead, the interfacial analysis indicates that the strongest trend of the spin Hall angle is associated with the chemistry of the upper YPtBi/W boundary: the effective SOT response tracks the integrated W concentration at that YPtBi surface. Meanwhile, a two-spin source analysis shows that the Pt-W-rich interlayer provides only a small positive correction, insufficient to explain the large negative effective spin Hall angle by itself. The dominant control variable is therefore inferred to be the incorporation of W into the upper YPtBi interface, which plausibly modifies the local electronic structure of YPtBi and amplifies the stack-level response. These results provide a more physically constrained interpretation of the stack behavior and identify a BEOL-compatible route to disordered topological spin-source layers for scaled SOT memory and compute-in-memory hardware.
