Foundry · Process and design rules
Our superconducting process, in detail.
For the engineer comparing foundries: materials and stack, junctions, integration and packaging, design rules, measured performance and downloads.
Materials and stack
The stack, layer by layer
300 nm aluminium ground plane on 500 µm high-resistivity silicon.
300 nm aluminium ground plane
500 µm high-resistivity silicon
Manhattan-style Josephson junctions
Air bridges
- Aluminium ground plane300 nm
- Coplanar-waveguide centre conductor, etched into the ground plane
- Air bridge
- Al/AlOx/Al Josephson junction (overlap, Manhattan-style)
- AlOx tunnel barrier
- High-resistivity silicon500 µm
Cross-section · thicknesses not to scale
Junctions
Josephson junctions
Al/AlOx/Al junctions, Manhattan-style or Dolan-bridge. Design with these variations in mind.
1–40 kΩ
Junction resistance range
Foundry page and brochures, 2025
±10%
Junction size precision, with >90% yield across a 4-inch wafer
Full wafer runs
±20%
Junction resistance variation across the wafer
Q-MPW Technical Guide, Feb 2026
±10%
Junction resistance variation within a block
Q-MPW Technical Guide, Feb 2026
Integration and packaging
From planar chip to packaged device
Air bridges, under-bump metallisation, flip-chip.
Air bridges
Part of the qualified Q-MPW process. Placement rules are under design rules below.
Under-bump metallisation and flip-chip
For 3D-integrated chips. First flip-chip integrated devices delivered October 2025.
Packaging
Our Qubit-in-a-Box packages show what we can package: the SMA case (gold-plated oxygen-free copper, 2 female SMA connectors) and Box20 (20 radial SMPM connectors).
- Box20 · Gold-plated OFHC copper
- 20 × Radial SMPM
Design rules summary
Before you draw
Key rules for the Q-MPW process. The full layer table and rules are in the Technical Guide.
The KLayout template is provided to Q-MPW participants.
Design rules at a glance
Technical Guide v1.0 §4- Ground-plane etch: linewidth and spacing
- ≥ 3 µm
- Air-bridge feet
- ≥ 10 µm
- Air-bridge clearance from etched metal
- ≥ 2 µm
- Air-bridge span
- ≤ 75 µm
- Flux holes: distance from CPW
- ≥ 10 µmNever in a waveguide, not in isolated metal islands
- Junction placeholder
- 10 × 10 µmMark each junction location with it, from the template
Measured performance
Measured on our own devices
Measured data, datasheets and publications are on the Evidence page, each with its source and date.
See the measured data256 µs
best measured qubit T1 (QiB0 datasheet)
QiB0, datasheet v2.0, Oct 2025
90–130 µs
average T1, QiB0
datasheet v2.0, Oct 2025
≳1M
resonator Qi at single-photon power
QiB0/QiB2 datasheets
250 µs
T1 demonstrated on the Q-MPW process (Technical Guide)
Q-MPW Technical Guide v1.0
Downloads
Technical documents
Send us what you're building.
A short description is enough to start. Attach a GDS file if you have one.