Research for the development of quantum computers is gaining speed. With the advancement of silicon spin qubit yield and uniformity, it is expected that the possibility of realizing quantum computers will be brought forward in the future.

Intel Labs and Components Research groups today announced that they have demonstrated that silicon spin qubits fabricated at Intel’s transistor research and development facility in Ronler Acres, Oregon, deliver industry-leading yield and uniformity. This announcement represents a significant achievement in the production of silicon spin qubits and represents a major advance in the fabrication of quantum chips based on Intel’s transistor manufacturing processes.

This study reportedly utilized the second-generation silicon spin test chip. The research team tested the device using the Intel Cryoprober, a quantum dot test device that operates at extremely low temperatures (1.7 Kelvin or -271.45 degrees Celsius), and succeeded in isolating 12 quantum dots and four sensors. This represents the industry's largest silicon electron spin machine, with one electron at each location across an entire 300mm silicon wafer.

While typical silicon spin qubits are presented in a single device, Intel’s research demonstrated success across an entire wafer. The test chip was fabricated using Intel’s cutting-edge extreme ultraviolet (EUV) lithography and demonstrated high uniformity, with a 95 percent yield across the wafer, the company said.

Using a cryoprobe with powerful software automation, more than 900 single quantum dots and 400 doublets formed on the last electron were realized, at 1 degree above absolute zero, in less than 24 hours.

Additionally, it has improved the yield and uniformity of the devices characterized at low temperatures compared to previous Intel test chips. This, Intel added, allows it to identify areas of the manufacturing process to optimize using statistical process control. This accelerates learning and is a key stepping stone to scaling to the thousands or millions of qubits needed for commercial quantum computers.

Additionally, Intel has demonstrated the largest-scale single and dual quantum dot demonstrations using cross-wafer yield to automate data collection across wafers in a single-electron system. This is described as a significant step toward potential scaling to the thousands or millions of qubits needed for commercial quantum computers, through increased yield and uniformity in devices characterized at lower temperatures compared to previous Intel test chips.

“Intel is making continued progress toward manufacturing silicon-skin quantum chips using our own transistor fabrication technology,” said James Clarke, director of Intel’s quantum hardware business. “Achieving high yields and uniformity validates that manufacturing quantum chips on Intel’s existing transistor process nodes is the right strategy and a robust success strategy as the technology matures for commercialization.”

Meanwhile, the full results of the study were presented at the 2022 Silicon Quantum Electronics Workshop in Orford, Quebec, Canada on October 5, 2022.