Electrochemical Deposition of Indium for Scalable 3D Quantum Chiplets

This study investigates the electrochemical deposition of indium thin films on copper and ruthenium seed layer for potential application in scalable 3D quantum chiplets. Our findings reveal a remarkable seed layer-dependent change in superconducting behavior: indium on copper exhibits Type-II superconductivity, while indium on ruthenium maintains Type-I superconductivity. Both systems show enhanced critical temperatures, Tc ≈4.3K for In/Cu and Tc ≈ 3.7K for In/Ru, compared to bulk indium (3.41K). These seed layer-dependent properties offer unique advantages for different quantum computing applications, potentially enabling tailored superconducting interconnects in 3D-integrated quantum architectures.