Patent ID: 11862593
Assignee: MICROSOFT TECHNOLOGY LICENSING, LLC
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. A cryogenic electronic chip, comprising:
a semiconductor die including a bond pad; and
an under bump metallization (UBM) stack on semiconductor die, the UBM stack including:
an adhesion and barrier layer on the bond pad;
a conductive pillar on the adhesion and barrier layer, the conductive pillar being a solder wetting layer of the UBM stack and having a thickness; and
an indium superconducting solder bump on the conductive pillar, the thickness of the conductive pillar having a value great enough to prevent intermetallic regions in the conductive pillar that form due to interdiffusion between the conductive pillar and the indium superconducting solder ball during heat treatments and storage at room temperature from extending through the thickness of the conductive pillar to the adhesion and barrier layer.