Silicon (Si) Substrate
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**Superconducting Materials**

 

The Foundation of Most Quantum Chips

**Non-superconducting — dielectric substrate**

Silicon (Si) Substrate
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The Foundation of Most Quantum Chips

 **Role in quantum circuits** 

Substrate / foundation for depositing superconducting thin films and qubit circuits

 **Why it matters** 

High-resistivity intrinsic silicon is a common substrate because semiconductor
            fabrication techniques are directly compatible. It enables patterning of qubits using
            electron-beam and optical lithography at scale, including double-sided qubit chip
            fabrication workflows.

 **Key facts** 
* Dielectric constant ~11.7; extremely well-characterised
* Float-zone (intrinsic) Si has very low impurity levels
* Compatible with standard cleanroom microfabrication tools
* Loss tangent must be carefully managed at millikelvin temperatures
* Supports double-sided 3-inch wafer fabrication workflows