Contact Pad Design Considerations for Semiconductor Qubit Devices for Reducing On-Chip Microwave Crosstalk

Abstract

Reducing on-chip microwave crosstalk is crucial for semiconductor spin qubit integration. Toward crosstalk reduction and qubit integration, we investigate on-chip microwave crosstalk for gate electrode pad designs with (i) etched trenches between contact pads or (ii) contact pads with reduced sizes. We conclude that the design with feature (ii) is advantageous for high-density integration of semiconductor qubits with small crosstalk (below -25 dB at 6 GHz), favoring the introduction of flipchip bonding.

Cryogenic flip-chip interconnection for silicon qubit devices

“…RF crosstalk is also an important aspect for future large-scale integration, where flip-chip bonding may also help. 21) Here we focus on the technique called RF reflectometry, which is often employed for fast qubit readout, for RF performance characterization. [22][23][24][25][26][27][28] Figure 3(a) shows an equivalent circuit diagram.…”