Quantum startup Diraq is to produce sample devices at GlobalFoundries fabs, making it another developer following Intel down the route of using standard CMOS production techniques to build toward full-scale quantum systems.

The contract manufacturer is to produce sample devices that combine both quantum and classical circuitry on a single slab of silicon.

Diraq's technology is based on electron spins in silicon quantum dots, like that of Intel. Earlier this year, the company announced a funding round that brought its total development reserves up to $120 million, including research funding from Australian and US government programs.

Andrew Dzurak, founder and chief executive at Diraq, has previously said that Diraq aims to have a "commercially relevant" quantum system within five years, and produce fault-tolerant hardware based on "many millions" of qubits inside a ten-year horizon. Quantum industry watchers will have heard all this many times before, however.

The move with GlobalFoundries is to demonstrate that Diraq''s silicon qubit design can be implemented using standard production processes with existing production tools and integrate with standard CMOS transistors, which Diraq says is crucial to increasing the number of qubits on a chip toward the million mark and beyond.

"Just as modern chipmaking allows millions of transistors to be crammed onto a regular chip, we can get millions of qubits on a quantum chip," Dzurak said in an interview with Bloomberg, claiming that "Quantum computing can be made much cheaper and more accessible than competing qubit technologies."

Diraq said it has designed sample chips that will be manufactured this year by GlobalFoundries using its 22nm 22FDX Silicon-on-Insulator process technology, possibly as early as this month.

If all goes as planned, it hopes to be able to scale up production toward its goal of a complete quantum computing system by 2028. It isn't clear if this means Diraq intends to use GlobalFoundries fabrication plants to manufacture the production chips.

However, Diraq says the viability of its technology has already been demonstrated using devices manufactured by Belgian research and development outfit Imec (Interuniversity Microelectronics Center).

These were produced using standard 300mm wafers and claimed by Diraq to demonstrate single qubit control fidelity of 99.9 percent, where fidelity is a measure of how effectively a quantum computer can perform operations without errors due to noise or decoherence.

The devices featured a layout similar to earlier work by Diraq team members, but were redesigned and fabricated by Imec using their 300mm fabrication line.

A spokesperson at GlobalFoundaries told us via email that its technical team had discussed designs for CMOS-based spin qubits for a number of years.

"GF’s 22FDX transistor technology has a number of advantages that make the transistors work extremely well at cryo temperatures (1 kelvin), and are also well suited to making spin qubits. The chip that Diraq is taping out this month, which GF will fabricate, is the first chip that GF will have made for Diraq, and is based on Diraq proprietary qubit and transistor circuit designs. Diraq will receive a number of chips from this initial fabrication cycle with GF, due later this year. There will be a number of future chips designed by Diraq that will be fabricated by GF over the coming years, under standard commercial supply agreements."

GlobalFoundries would, according to the spokesperson, be a long-term Diraq supplier for "both qubits and also for the classical electronics chips that are used to control and measure the qubit chips - but which also need to operate at 1 kelvin."

Like Intel's silicon quantum dot chips, Diraq's devices are designed to operate at cryogenic temperatures, meaning they must be cooled close to absolute zero.

Intel recently revealed a method of testing its prototypes using a cryogenic chamber large enough to hold an entire silicon wafer, and last year was able to provide research facilities and universities in the US with samples of its Tunnel Falls 12-qubit test chip to evaluate.

Diraq isn't the only Aussie quantum startup that has chosen to work with GlobalFoundries. Back in 2022, a company called Archer Materials said it was working with the fab operator on manufacturing its quantum chip technology, which it claimed was able to operate at room temperature.®

https://www.theregister.com//2024/06/13/diraq_globalfoundries_sample_chips/