Three‐Dimensional Atomic‐Scale Tomography of Buried Semiconductor Heterointerfaces

Atom probes generate three‐dimensional atomic‐scale tomographies of material volumes corresponding to the size of modern‐day solid‐state devices. Here, the capabilities of atom probe tomography are evaluated to analyze buried interfaces in semiconductor heterostructures relevant for electronic and quantum devices. Employing brute‐force search, the current dominant reconstruction protocol to generate tomographic three‐dimensional images from Atom Probe data is advanced to its limits. Using Si/SiGe heterostructure for qubits as a model system, the authors show that it is possible to extract interface properties like roughness and width that agree with transmission electron microscopy observations on the sub‐nanometer scale in an automated and highly reproducible manner. The demonstrated approach is a versatile method for atomic‐scale characterization of buried interfaces in semiconductor heterostructures. Heterostructures are ubiquitous in semiconductor science and technology enabling building blocks for transistors, lasers, and qubits. The buried interfaces in these heterostructures define the performance and thus need to be meticulously engineered and controlled. A method to map such interfaces on the near‐atomic scale using three‐dimensional atom‐by‐atom tomography is presented providing valuable insights into the nature of semiconductor heterostructures.