Interposer for Quantum Computing

Interposer is a chip which connects devices(dies) to each other and the PCB board or substrate. It is widely used in semiconductor industry as IC packaging processes. With interposer, higher bandwidth in smaller space can be realized and can be further integrated with other prepattern devices on it. To gain those advantages, fabricates interposer requires further understanding of fabrication technologies and execution complicates processes compares to traditional wire bonding.

Here in HNF, in order to connect the device (Qubit for example)/ chip carrier to another, an interposer is design to be an electrical interface to bridge devices. Especially, quantum computer usually requires Qubit/DAC connections in fridge temperature. With interposer, shortening the route (wiring/leads) to dies and surface area which benefits the thermal budgets in the mini-K cryostat. HNF clean room providing the understanding of fabrication technologies to process interposer on difference substrates with various materials. With laser pattern generator, high lateral resolution (down to 1um) and overlay accuracy (within 1-2 um) can be achieved. Together with Reactive Ion Etcher (RIE) and sputter/ALD/evaporator, simple 2.5D interposer through silicon vias (TSV) can be produced in HNF clean room as a prototype for research propose.