Atomically Precise Scanning Probe Based Analysis of Activated Dopants for 2D Micro Electronics

Atomically precise placement of dopants in 2D planes inside semiconductor crystals has shown enormous potential for creating valuable structures such as analog quantum simulations and devices such as qubits for quantum computers ultra-high performance analog transistors, and potentially quantum metamaterials with designer quantum properties. These applications will have an enormous impact on energy efficiency as well as other important attributes important to our nation’sinterest. This technology has a number of unique and powerful advantages already realized and more capabilities are being developed: Ability to place dopant atoms (primarily P donors) in a single buried (100) plane of a Si or Ge crystal. Emerging capabilities to place acceptor (B and Al) dopants and heavier donor (As) dopants. Doping levels can be extremely high in a single (100) plane. As much as ¼ monolayer of P atoms in a single Si (100) plane renders metallic conducting material that is also direct bandgap. Even higher doping levels have been obtained and ongoing improvements in doping levels may produce 2D superconducting semiconductor material. These delta doped layers have 5-6 orders of magnitude less 1/f noise. The ability to pattern with atomic precision the 2D regions that dopants are placed in. Near deterministic control of doping in a given region. By repeating these 2D patterning and dopant placement after epitaxial growth the atomically precise dopant placement can be extended to 3D designs. A current limitation in these potentially revolutionary devices and structures is the ability to control exactly the number of dopant atoms that end up in specific nanoscale elements. For instance in spin donor qubits the number of dopant atoms that make up a single qubit is extremely important and currently the methods of placing the dopant atoms is stochastic in nature. There are attempts at developing methods that are deterministic, but there is no dopant counting metrology technology to guide this development and verify the numbers of dopant atoms in production. Building on our Atomically Precise Patterning tool which is integral to creating these 2D structures and devices, we will integrate into this tool the ability to count individual dopant atoms beneath the surface and verify that specific nanoscale areas contain the desired number of dopant atoms. This will be accomplished by using a specific modality of scanning tunneling microscope imaging. We intend to develop a method that operates at room temperature rather than cryogenic temperatures which will make the process more affordable and will reach a larger market.