Microchips are made using extraordinary technology. One has to go a little deeper inside the device to better appreciate it. Let's start by getting a sense of scale :
- a human hair is about 60 micrometers diameter (60 µm) or 60 000 nanometers (60 000 nm). For those who are used to the imperial system that corresponds to 0.0023 inch.
- visible light has a wavelength range of 400 nm (blue) to 700 nm (red). The pictures of microchip structures shown below have features much smaller than light itself. This is why scientists need to use electron beam microscopy instead of visible light microscopy to view the devices. Light itself is too "big" to show the small features.
The Apple Watch uses technology that
have features that are 28 nm in size. Next generation Watches may even use 14 nm technology.
The Apple Watch has 8 GB of storage. This means that the memory chip has 64 billion transistors! 64 000 000 000 parts on your wrist!
I attached a few images found on the web to show dimensions of structures of electronic devices, which are very similar to the ones used in the Apple Watch.
This one shows the side view of multiple layers that form a chip. Typical CMOS fabrication processes have more than 20 layers of materials (metals, semiconductors, oxides) that are patterned using masks and etches to create the chip. Each layer is patterned before another layer is added. M1, M2, M3, are metal layers that are used to connect individual electronic components together.
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This shows structures of flash memory. I think the oxide layers were etched out to show just the metal and semiconductor layers and give it a 3D appearance.
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A top view of an microelectronic circuit.
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Here's a side view of a single SiGe transistor capable of very high speed operation. The scale is shown at the bottom left (20 nm).
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Here's another side view show feature size.
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Personally, the Apple Watch is not my thing (heck, I don't even own a cell phone) but there's a lot of beauty in the astonishing technology that goes into the design and fabrication of microchips.
Michel
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