The development of useful quantum technologies will heavily rely on assembling many sub-systems that exhibit quantum properties. These systems do not spontaneously assemble themselves into useable quantum machines: they rely on advanced fabrication techniques at micro- and nanometre scales. Examples of such techniques include the fabrication of electrodes and waveguides for trapped ions, of Josephson junctions and microwave chips for superconducting circuits, of electrodes for the control of quantum dots or the fabrication of low-disorder semi-conductors for the operation of Majorana Zero Modes.
The development of useful quantum technologies will heavily rely on assembling many sub-systems that exhibit quantum properties. These systems do not spontaneously assemble themselves into useable quantum machines: they rely on advanced fabrication techniques at micro- and nanometre scales. Examples of such techniques include the fabrication of electrodes and waveguides for trapped ions, of Josephson junctions and microwave chips for superconducting circuits, of electrodes for the control of quantum dots or the fabrication of low-disorder semi-conductors for the operation of Majorana Zero Modes.
Quantum computing is rapidly evolving from theoretical frameworks to functional hardware, with physical qubits now being realized across multiple experimental platforms. Precision nanofabrication has enabled the development of low-loss, high-coherence quantum devices. Among the various approaches, superconducting circuits and trapped-ion systems have emerged as the most advanced and experimentally successful platforms for realizing controllable and scalable qubits. This review presents an overview of nanoscale fabrication techniques employed in these two architectures. We first outline the operating principles that define qubit behavior, followed by a discussion of representative device designs and fabrication workflows. In superconducting circuits, we examine processes such as thin-film deposition, lithographic patterning, and Josephson-junction fabrication that determine key parameters including qubit frequency, anharmonicity, and coherence. For trapped-ion systems, we describe the transition from bulk electrode assemblies to microfabricated surface traps produced using photolithography, metal deposition, and dielectric layering, where electrode geometry and surface treatment directly influence ion confinement and motional heating. We further discuss fabrication-related challenges, including dielectric loss, surface contamination, and material defects that limit coherence and reproducibility, along with emerging mitigation strategies such as advanced cleaning, low-loss materials, and improved surface engineering. By drawing parallels between these two leading platforms, this review highlights that continued progress in nanofabrication remains central to realizing scalable, high-fidelity quantum processors.
Superconducting circuits have emerged as a highly promising platform for quantum computing, among other divices based on Josephson junctions. The fabrication and testing of these devices requires especiallized nanofabrication facilities and milikelvin range testing equipment. In the search for the fabrication of these devices we have ran into limitations which forced us into creative solutions for the fabrications of these superconducting circuits and Josephson Junctions. Furthermore the development of these technologies allows for application in a wide range of research fields such as quantum computing, magnonics, micro-electromechanical systems and more.
Ongoing research at SUNY Polytechnic Institute to enable large scale fabrication of quantum devices with tightly controlled performance characteristics will be presented. Josephson junctions and transmon qubits patterned with 193 nm lithography will be used to illustrate how advanced process tools can control critical dimensions of devices, necessary for building larger ensembles of qubits. Advances in the CMOS industry enable superior surface roughness and interface quality to be achieved across the entire 300mm wafer – some examples will be presented. The integration of photonic circuits (waveguides and on-chip cryogenic IR emitters) with superconducting Josephson junctions to enable large-scale neuromorphic computing structures in the near future will be discussed. Ongoing work on developing materials and processes for UV-transparent photonic circuits at 300mm will be presented – such chips could be useful as part of the interface to trapped ion qubits. The talk will wrap up with a discussion of the synergies in technology development, and functionality integration that can be achieved using an advanced fabrication facility.
Microfabrication of atomic and optical components plays an increasingly important role in the development of quantum technologies and their application in fields such as sensing, timing and spectroscopy. Driven forward by advances in micro-electromechanical systems (MEMS), new techniques are now used for critical atomic and optical components at the heart of quantum technologies, including diffractive optics, atomic vapour cells and miniaturised ion traps. A range of other miniaturised technologies, such as hollow-core waveguides and integrated photonics, also add to the capabilities of emerging quantum devices. These components offer the potential to scale atomic quantum devices down to chip-scale packages, increasing the application range and facilitating their in-field deployment. Additionally, miniaturisation may also unlock physical regimes, such as thin media effects and atom–interface interactions, opening avenues for new research which cannot be accessed using larger conventional components.
Surface electrode ion trap is a promising candidate for quantum information processing (QIP), due to its feasibilities towards large-scale fabrication and on-chip electro-optical integration. In this paper, surface electrode ion traps on different substrates (e.g., high-resistivity silicon, silicon with ground plane and glass) are fabricated, assembled and tested. To simultaneously leverage the established fabrication technique of silicon and superior insulation property of glass, we further demonstrate a novel ion trap design with heterogenous integration of silicon and glass, acting respectively as ion trap and interposer substrates. The vertical connection between the silicon ion trap and the glass interposer is achieved by through silicon via (TSV) and micro bump. This silicon-glass integrated system advances the development of ion trap and enriches the toolbox of scalable QIP.
Quantum computing holds the promise of exponential speedup compared to classical computing for select algorithms and applications. Relatively small numbers of logical quantum bits or qubits could outperform the largest of supercomputers. Quantum dots in Si-based heterostructures and superconducting Josephson junctions are just two of the many approaches to construct the qubit. These, in particular, bear similarities to the transistors and interconnects used in advanced semiconductor manufacturing. While initial results on few-qubit systems are promising, advanced process control is expected to improve the qubit uniformity, coherence time, and gate fidelity needed for larger systems. This can be realized through the systematic characterization of film growth, interface control, and patterning.