TRAILBLAZER: Electron-enhanced Atomic Layer Processing for Revolutionary Thin-film Technologies

California Institute Of Technology, Pasadena CA

Investigators

Abstract

New technologies are needed for the U.S. to maintain leadership in the development and manufacture of next generation computer chips. A critical step in the manufacture of computer chips is the deposition of electronic materials, layer by layer, onto a surface, in precise patterns to create a circuit. A particularly precise method is called atomic layer processing, which can deposit a single layer of atoms onto a surface (atomic layer deposition), or remove a single layer of atoms from a surface (atomic layer etching). However, these processes require very high temperatures and do not work for all electronic materials. A bold new idea is to use electrons to enable the deposition or etching processes to work at lower temperatures. In the research funded by this award, atomic layer processing systems will be equipped with special emitters that direct an electron beam to the surface and drive reactions that would not otherwise be possible. Special instruments designed to work inside the atomic layer processing equipment will measure the progress of the reactions in real time, providing fundamental information that can be used to control and improve the process. Once this concept has been demonstrated, the project seeks to make superconducting thin films that can be used as “qubit” chips in quantum computers. The project will also pioneer new ways to train students in use of clean room technology that is central to the semiconductor industry. The training modules will use augmented reality / virtual reality tools to make this training available to students who do not have access to clean room facilities. Atomic layer processing (ALP) is based on self-limiting chemical reactions of gases, plasmas, or molecular precursors at a surface, enabling deposition and etching with monolayer control. This project will advance fundamental understanding of electron-enhanced ALP (EE-ALP), where electrons are used to drive electron-stimulated reactions that would otherwise not occur in the given conditions. Although electron-stimulated chemistry has been studied in other contexts, the chemical mechanisms occurring in the unique self-limiting surface reactions of EE-ALP remain largely unexplored. A key component of our technical approach will be the first use of mid-infrared frequency combs to track the dynamics of interacting chemical species in ALP in real time, allowing a quantitative description of the chemical kinetics to be revealed. The fundamental understanding created by this project will open new process windows and new chemistries for deposition and etching of thin films with atomic precision, which is key to enabling future technologies such as quantum computers. The knowledge will also impact adjacent fields involving molecule-substrate interactions such as heterogeneous catalysis. Anticipated Transformative Impact:Superconducting thin films for quantum computer chips. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.