Crafting Microchips: A Step-by-Step Process

Building a microchip is a marvel of precision, turning raw silicon into intricate circuits that power our world. This complex process unfolds in stages, each demanding cutting-edge tools and flawless execution.

It begins with a silicon wafer, crafted from purified silicon cut into thin, round slices. Silicon’s ability to switch between conducting and insulating makes it perfect for microchips. The wafer is polished and cleaned to eliminate contaminants, preparing it for the intricate steps ahead.

Photolithography is the heart of the process. A light-sensitive layer, photoresist, coats the wafer, and a mask bearing the circuit design is aligned above it. Ultraviolet light passes through, hardening the exposed photoresist; unexposed areas are rinsed off, exposing the silicon in the pattern. ASML’s extreme ultraviolet (EUV) lithography machines shine here, using tiny wavelengths to carve features mere nanometers wide.

A high-resolution photo of a silicon wafer.

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Etching follows, where chemicals or plasma sculpt the exposed silicon, shaping transistors and pathways. Doping then tweaks the silicon’s properties—ions like boron or phosphorus are implanted, creating conductive or resistive zones that form the transistors, the chip’s on-off switches.

Next, insulating layers (often silicon dioxide) are added via oxidation to isolate components, while conductive metals like copper link transistors into a network. This layering repeats dozens of times, building a 3D circuit with exact alignment.

After completion, the wafer is tested, then diced into individual chips. These are packaged and retested for reliability. Performed in sterile clean rooms, this process yields chips with billions of transistors, fueling devices from phones to supercomputers.