- By Sebastian Anthony
I don’t think you appreciate just howmagical the computer chip at the heart of your smartphone or PC really is. In the case of a smartphone’s SoC, you essentially have a single less-than-a-square-inch package that enables you to do almost anything, from playing games, to accessing a cellular network, to contactlessly paying for your groceries. To do this, there are billions of tiny switches inside each chip that switch on and off up to four billion times per second. A modern computer chip really is quite miraculous — especially when you consider that the first integrated circuits, which were only built 50 years ago, maxed out at around a dozen transistors.
It isn’t just the rich, society-altering functionality of advanced computer chips that blows my mind, though — it’s also the utterly gobsmackingly miniature scale of the things. In a modern chip, built using a 20nm or 22nm process, each transistor is roughly 30 nanometers square. A single SRAM cell, which consists of six transistors, is about 0.1 micrometers square (or 100 nanometers square, if you prefer). If you slice a tiny sliver off a human hair, you could get about 500 SRAM cells — 3000 transistors — into the cross section. You could even squeeze about 60 SRAM cells, or 360 transistors, into a footprint the size of a human red blood cell — and somehow, despite a single chip containing billions of these tiny things, they can operate continuously at billions of hertz for decades.
I could go on, but this video does a pretty good job of showing you just how much stuff we cram into a single chip. It starts off with a photo of a de-capped chip, and then zooms in through a series of closer photos before switching over to some scanning electron microscopy.
There are a couple of things to note about this video. First, it’s quite an old chip — a modern chip made by Intel or TSMC would be much more dense. Second, you can only see the first couple of layers — some connecting copper wires, and the tops of some transistors; Intel’s latest 14nm Broadwell chips consist of 13 layers.
This is what a modern chip looks like, under an electron microscope — in this case, one of Intel’s 14nm FinFET Broadwell chips.
