ProQuantum – Process Development for a Saxon Spin Qubit Pilot Line

Work packages

The technological challenges are addressed in three closely interlinked work packages (WP) to ultimately demonstrate a complete integration route for silicon spin qubits:

WP1: Process optimization on 200 mm wafers

To significantly improve qubit quality (fidelity), charge noise in the gate oxide must be minimized.

• Gate oxide development: Use of novel hafnium (Hf)- and zirconium (Zr)-based dielectrics with a low thermal budget
• Gentle etching processes: Development of defect-minimizing wet chemical cleaning and dry etching techniques to protect sensitive layers
• Superconducting electrodes: Integration of CMOS-compatible superconducting nitrides (such as HfN, TiN, and ZrN) into the gate stack

WP2: Process transfer to the 300 mm technology node

True scaling to thousands of qubits requires transition to industrial 300 mm wafer formats.

• 2DEG substrate development: Evaluation of regional suppliers in Saxony for advanced Si/SiGe heterostructures
• Cross-tool process transfer: Adaptation of deposition, etching, and cleaning processes to the changed chamber geometries of 300 mm industrial tools
• Advanced lithography: Combination of DUV and electron-beam lithography (e-beam) for gate structures with minimal pitch (< 80 nm) and alignment accuracy down to 10 nm

WP3: Rapid characterization of spin-qubit processes

A reliable pilot line requires extremely precise and fast defect and failure analysis.

• Noise measurements & defect analysis: Application of advanced methods such as charge pumping and conductance measurements for precise energetic identification of atomic-scale defects
• Modeling: Development of temperature-dependent models to accelerate process evaluation

Future perspectives and economic impact

ProQuantum secures a technological leadership position for Saxony and Germany in the global quantum race.

• Benefits for industry: Commercial customers and foundries gain access to a scalable and reliable gate module. Technological know-how can be licensed flexibly to partners such as Infineon.
• Ecosystem synergies: The open pilot platform creates a unique infrastructure available to universities, start-ups, and SMEs under fair conditions (contributing to UN Sustainable Development Goal SDG 9).
• Future workforce: Integration of research outcomes into academic training helps build the next generation of quantum experts directly in Saxony.