The Intel Labs and Components Research organizations have demonstrated the industry's highest reported yield and uniformity of silicon spin qubit devices developed at Intel's transistor research and development facility, Gordon Moore Park at Ronler Acres in Hillsboro, Oregon. 

This achievement represents a significant milestone for scaling and working toward fabricating quantum chips on Intel's transistor manufacturing processes.

The research was conducted using Intel’s second-generation silicon spin test chip. 

Through testing the devices using the Intel cryoprober, a quantum dot testing device that operates at cryogenic temperatures (1.7 Kelvin or -271.45 degrees Celsius), the team isolated 12 quantum dots and four sensors. 

This result represents the industry's largest silicon electron spin device with a single electron in each location across an entire 300-millimetre silicon wafer.

Today’s silicon spin qubits are typically presented on one device, whereas Intel’s research demonstrates success across an entire wafer. Fabricated using extreme ultraviolet (EUV) lithography, the chips show remarkable uniformity, with a 95% yield rate across the wafer. 

The cryoprober and robust software automation enabled more than 900 single quantum dots and more than 400 double dots at the last electron, which can be characterized at one degree above absolute zero in less than 24 hours.

Increased yield and uniformity in devices characterized at low temperatures over previous Intel test chips allow Intel to use statistical process control to identify areas of the fabrication process to optimize. This accelerates learning and represents a crucial step toward scaling to the thousands or potentially millions of qubits required for a commercial quantum computer.

Additionally, the cross-wafer yield enabled Intel to automate data collection across the wafer at the single electron regime, which enabled the largest demonstration of single and double quantum dots to date. 

This increased yield and uniformity in devices characterized at low temperatures over previous Intel test chips represents a crucial step toward scaling to the thousands or potentially millions of qubits required for a commercial quantum computer.

“Intel continues to make progress toward manufacturing silicon spin qubits using its own transistor manufacturing technology,” says James Clarke, Director of Quantum Hardware, Intel. 

“The high yield and uniformity achieved show that fabricating quantum chips on Intel’s established transistor process nodes is the sound strategy and is a strong indicator for success as the technologies mature for commercialization.”

“In the future, we will continue to improve the quality of these devices and develop larger scale systems, with these steps serving as building blocks to help us advance quickly.”

Clarke further explains Intel’s quantum computing breakthroughs.

“Quantum computing employs the properties of quantum physics like superposition and entanglement to perform computation. Traditional transistors use binary encoding of data represented electrically as on or off states. Quantum bits or qubits can simultaneously operate in multiple states enabling unprecedented levels of parallelism and computing efficiency,” he says.

“Today’s quantum systems only include tens or hundreds of entangled qubits, limiting them from solving real-world problems. To achieve quantum practicality, commercial quantum systems need to scale to over a million qubits and overcome daunting challenges like qubit fragility and software programmability.”

Adding how Intel Labs is working to overcome these challenges, Clarke notes, "Firstly, Intel is leveraging its expertise in high-volume transistor manufacturing to develop 'hot' silicon spin-qubits, which are much smaller computing devices that operate at higher temperatures."

"Secondly, the Horse Ridge II cryogenic quantum control chip provides tighter integration. And thirdly, the cryoprober enables high-volume testing that is helping to accelerate commercialization."

“Even though we may be years away from large-scale implementation, quantum computing promises to enable breakthroughs in materials, chemicals and drug design, financial and climate modelling, and cryptography.”  

The full results of this research will be presented at the 2022 Silicon Quantum Electronics Workshop in Orford, Québec, Canada, on October 5, 2022.