Probing single electrons across 300-mm spin qubit wafers.

Area of Science:

• Quantum Computing
• Solid-State Electronics
• Materials Science

Background:

• Fault-tolerant quantum computers require millions of physical qubits.
• Solid-state qubit fabrication needs to match the scale of the complementary metal-oxide-semiconductor (CMOS) industry.
• Cryogenic testing must scale to support high-volume qubit production and characterization.

Purpose of the Study:

• To present a cryogenic wafer probing technique for high-volume spin qubit testing.
• To enable rapid feedback for optimizing CMOS-compatible fabrication processes.
• To assess qubit yield and process variation at the 300-mm wafer scale.

Main Methods:

• Utilized a cryogenic 300-mm wafer prober to test hundreds of industry-manufactured spin qubit devices at 1.6 K.
• Automated measurements of spin qubit operating points and single-electron transitions across full wafers.
• Analyzed random variations in single-electron operating voltages.

Main Results:

• Demonstrated a scalable testing process for spin qubits using CMOS industry techniques.
• Achieved high yield and low process variation in spin qubit devices fabricated at the 300-mm scale.
• Observed low levels of disorder in optimized fabrication processes.

Conclusions:

• The developed cryogenic testing method facilitates the optimization of fabrication processes for large-scale quantum computing.
• Application of CMOS industry standards to spin qubit fabrication and testing is crucial for advancing quantum computing.
• This work shows significant progress towards building fault-tolerant quantum computers with high-yield spin qubits.