Breakthrough Diamond Bonding Technique Revolutionizes Quantum Device Manufacturing

A breakthrough in bonding synthetic diamonds to other materials has been achieved by researchers at the University of Chicago’s Pritzker School of Molecular Engineering (PME) and Argonne National Laboratory. This novel technique, published in Nature Communications, enables the integration of diamond into quantum and conventional electronics, overcoming a major hurdle in harnessing the material’s exceptional properties.

Diamond is prized for its durability, thermal conductivity, and dielectric strength, but its homoepitaxial nature made it difficult to integrate with other materials. The new method, developed by Assistant Professor Alex High’s lab, involves surface treatment and annealing to bond diamond membranes as thin as 100 nanometers to materials like silicon, sapphire, and lithium niobate.

This innovation has the potential to revolutionize quantum computing, sensing, and even phone and computer manufacturing. Key researchers involved in this work include Xinghan Guo, F. Joseph Heremans, Peter Maurer, and Avery Linder. The University of Chicago’s Polsky Center for Entrepreneurship and Innovation is commercializing the patented process.

Diamond Bonding Breakthrough for Quantum Devices

A novel technique has been developed to bond diamonds directly to materials that integrate easily with either quantum or conventional electronics. This breakthrough, published in Nature Communications, allows for the greater integration of synthetic diamonds into devices, improving how both quantum and conventional electronics are built.

Diamond is an elite material for both quantum and conventional electronics due to its durability, inertness, rigidity, thermal conductivity, and chemical well-behaved properties. However, diamond only grows on other diamonds, making it difficult to integrate into devices without sacrificing its full potential or using large, expensive chunks of the precious material. The new technique, developed by researchers at UChicago PME’s High Lab and Argonne National Laboratory, creates a surface treatment to the diamond and carrier substrates that makes them attractive to each other, allowing for direct bonding.

The team bonded crystalline membranes as thin as 100 nanometers while still maintaining a spin coherence suitable for advanced quantum applications. This technique has the potential to greatly influence the ways we do quantum and even phone or computer manufacturing. The researchers have patented the process and are commercializing it through the University of Chicago’s Polsky Center for Entrepreneurship and Innovation.

Perfect Defects

Unlike jewelers, quantum researchers prefer a slightly flawed diamond. By precisely engineering defects in the crystal lattice, researchers create durable qubits ideal for quantum computing, quantum sensing, and other applications. Diamond is a wide bandgap material that is inert and has great thermal and electronic properties, making it beneficial to various fields.

However, as thin diamond membranes were previously difficult to integrate directly into devices, this required larger—but still microscopic—chunks of the material. The new technique allows for the integration of these thin diamond membranes into devices, bringing us closer to applications such as quantum bio-sensing.

Sticky Diamonds

In diamonds, each carbon atom shares electrons with four other carbon atoms, creating a hard, durable internal structure. However, if there is no other carbon atom nearby to share electrons, this creates “dangling bonds” on lonely atoms looking to partner. Creating a diamond surface full of these dangling bonds allowed the team to bond the nanometer-scale diamond wafers directly to other surfaces.

The researchers compare the new diamond technique to the advances in complementary metal-oxide semiconductors (CMOS) over the years, from bulky individual transistors in labs in the 1940s to the powerful, tiny integrated circuits filling computers and phones today. They hope that their ability to generate these thin films and integrate them in a scalable fashion can lead to something like CMOS-style revolution for diamond-based quantum technologies.

This breakthrough has the potential to greatly influence the ways we do quantum and even phone or computer manufacturing, bringing us closer to applications such as quantum bio-sensing and advanced quantum computing.