The Semiconductor Industry’s Unseen Role in Quantum’s Future
Quantum computing has often been portrayed as a radical break from the past, a leap into a new computational paradigm governed by quantum mechanics, not classical logic. Yet behind the awe-inspiring physics and futuristic rhetoric, a less visible but equally critical player is quietly shaping the field: the semiconductor industry. Erik Hosler, a quantum technologist deeply embedded in photonics-driven quantum systems at PsiQuantum, emphasizes that traditional semiconductor infrastructure isn’t just helpful, it’s indispensable. He sees it not as a relic of the past but as the scaffolding of the quantum future.
While quantum computing is built on principles that defy classical intuition, like superposition, entanglement, and probabilistic measurement, its practical realization depends on a surprisingly familiar foundation. Lithography, etching, deposition, packaging, and metrology, all cornerstones of the semiconductor world, are being reimagined and retooled to support the needs of qubits instead of transistors. That makes the semiconductor industry a silent enabler of quantum progress.
The Quiet Backbone of Quantum Fabrication
Quantum chips, particularly photonic ones, are produced using many of the same techniques used to make traditional silicon devices. Advanced lithography machines pattern waveguides and photon sources; dry etching defines component geometry; thin-film deposition coats surfaces with materials that modulate or guide light. Even cleanroom environments are the same.
This overlap has enabled quantum startups to outsource parts of their fabrication process to existing CMOS foundries. Leveraging these facilities, known for their rigor, precision, and scale, dramatically accelerates prototyping, reduces defects, and makes early production economically viable.
Erik Hosler observes, “The semiconductor industry and its technology are essential to building a useful quantum computer.” His remark reframes quantum progress as not only about quantum progress as not only about quantum logic, but also about leveraging decades of classical process expertise to build next-generation machines.
Lithography’s Second Act
Lithography may have been perfected for transistor manufacturing, but its role in quantum computing is no less vital. In photonic quantum chips, waveguide alignment, coupler precision, and grating profiles all rely on accurate patterning. For superconducting qubits, lithography defines Josephson junctions as microscopic tunnel barriers whose dimensions influence qubit frequency and fidelity.
While quantum devices often operate at larger feature sizes (hundreds of nanometers to microns), the tolerances are tighter. A few nanometers of line-edge roughness can lead to phase mismatches or excess loss in waveguides. Thus, equipment designed to produce 5 nm logic nodes is being reoriented to pattern structures five to ten times larger but with equal or greater precision demands.
The lithography industry’s investments in extreme ultraviolet (EUV) tools, proximity effect correction, and resist chemistry are all paying dividends in the quantum domain.
Packaging: From Interconnect to Isolation
Quantum computers require highly specialized packaging to isolate qubits from noise while routing control signals and cryogenically cooling the entire system. Here again, the semiconductor industry is indispensable. Flip-chip bonding, Through-Silicon Vias (TSVs), and 3D integration were all homed in the service of smartphone processors and graphics cards. But these same techniques now help connect photonic chips to lasers, detectors, and control electronics.
In superconducting systems, control lines must pass from room temperature to millikelvin stages without introducing thermal or electrical noise. Once optimized for RF chips and analog circuits, materials with low dielectric loss, precise impedance matching, and minimal parasitic capacitance features are repurposed for quantum interconnects.
These capabilities aren’t being developed from scratch for quantum; they’re being redirected from a semiconductor legacy decade in the making.
Metrology and Process Control
Process metrology, measuring whether a chip was fabricated to spec, is a crucial part of quantum manufacturing. But how do you inspect a single-photon source or a superconducting junction? The answer lies in modified versions of tools already common in CMOS fabs.
Scanning Electron Microscopes (SEMs), Atomic Force Microscopes (AFMs), and ellipsometers help measure geometry, roughness, and layer thickness in quantum chips. Scatterometry, which uses light diffraction to infer pattern dimensions, can identify sub-nanometer deviations in photonic circuits. These are the same systems used to tune critical dimensions in logic and memory chips.
Importantly, the automation developed for these tools, the feedback loops that adjust lithography exposure or etch timing based on real-time data, is now being adapted to quantum production. The semiconductor industry’s mastery of statistical process control enables repeatability, which is vital when manufacturing thousands or, eventually, millions of useable qubits.
Foundry Partnerships and Co-Development
Some of the world’s most advanced foundries are beginning to engage directly with quantum companies. Multi-project wafer runs allow startups to share mask sets and testing resources, lowering entry barriers. Meanwhile, co-development initiatives are emerging, where foundries experiment with quantum-friendly materials or process modules to support future scalability.
PsiQuantum, for instance, works closely with semiconductor manufacturing partners to refine the silicon photonics platform underlying its quantum chips. This collaboration allows rapid iteration and offers insights into process windows, thermal budgets, and feature scalability, all factors that would be impossible to explore in isolation.
These partnerships also help quantum firms access advanced process nodes, test equipment, and cleanroom capacity without building entire fabs from scratch, a capital expenditure that would otherwise be insurmountable.
When Classical Meets Quantum: The Integration Layer
No quantum computer operates in isolation. Control systems, error correction engines, and classical pre-processing units must sit alongside qubit arrays. This integration depends heavily on semiconductor principles: CMOS logic, high-speed DACs and ADCs, and cryo-compatible control electronics.
The industry is also exploring cryo-CMOS, a variant of standard logic designed to function reliably at temperatures near absolute zero. These chips live inside the cryostat with the qubits, minimizing latency and simplifying cabling. Designing, fabricating, and integrating cryo-CMOS chips requires semiconductor expertise and foundry access, yet another way classical tech enables quantum systems.
A Hidden but Central Contributor
Despite all this, the role of the semiconductor industry in quantum computing often goes unrecognized. The media focuses on breakthroughs in qubit count, coherence times, or quantum algorithms. Rarely do headlines mention the deep ultraviolet stepper that defined a crucial waveguide, or the PECVD tool that deposited an anti-reflective coating.
Yet these unglamorous contributions are what make those breakthroughs reproducible, scalable, and eventually commercial. The semiconductor industry isn’t competing with quantum. It’s enabling it.
From Backbone to Catalyst
Quantum computing may be defined by exotic physics, but its viability is grounded in centuries of collective manufacturing knowledge. The more quantum engineers push toward large-scale deployment, the more they depend on the infrastructure, tooling, and process control developed by the semiconductor world.
As quantum hardware inches closer to commercial viability, it becomes increasingly clear that its future is not decoupled from classical technology; it is built directly on top of it. The invisible scaffolding of the semiconductor industry provides the precision, repeatability, and scale that quantum systems require to move from the lab into practical, high-impact applications.
Quantum computing may seem like a technological development. In many ways, it is. But beneath that change lies the continuity of an industry that has quietly mastered the art of building the impossible, one layer at a time.
