The end is nigh

 Moore's Law is the empirical observation that the number of transistors in a dense integrated circuit doubles about every two year and it has approximately held true since it was proposed in 1965.

It is driven by the economics of the insatiable demand for ever increasing electronics complexity and the steady reduction in feature size in the fabrication of silicon chips (integrated circuits).

In 2013 Robert Calwell vowed the end would come in 2022, maybe even 2020, with the herald of 7nm and even 5nm feature size.

And today the BBC has announced that Apple's new flagship iPhone 12 will incorporate the "A14" processor with 5nm feature size - the chip's transistors have been shrunk down - the tiny on-off switches are now only about 25 atoms wide - allowing billions more to be packed in.

These electronic chips use "solid state" technology, i.e. they have no moving parts which makes it sound like they can never wear out, will last forever short of physical damage. Alas, such is a dream. I am well used to using Flash and other types of non-volatile solid state memory (chips) in my work and I am all too aware that the specification documents mention a lifetime of sometimes as little as 100,000 re-write cycles. When software is running at GHz speeds this many can clock up quite fast!

Chips are made by first growing a very pure silicon crystal, slicing it into wafers, and then diffusing into it a photographic pattern of known amounts of certain impurities that give the silicon its required special electrical properties. Diffusion (the intermingling of substances by the natural random movement of their particles) is both the essential mechanism and Achilles' heel of solid state chips.

Back in college days I was told that the lifetime of a solid state circuit was limited by diffusion - what can be diffused in to make it work can, by the same token, diffuse out and self destroy it. OK, it is diffused in at high temperature where the particles are in much stronger random movement, so what may take seconds to diffuse in might take many years to diffuse out at room temperature. But the smaller the feature size, the more likely that diffusion defects can occur - the particles have less distance to move.

The aging problem is discussed in this paper - so I am not just imagining it!  Many people regard their cell-phone as a consumable item, with expectation that it be replaced after a year or so. Those people may have limitless bottoms to their purses but I, for one, am happy enough with my Pixel 2 and have no desire to shell out to upgrade it. So I'm hoping that all those billions of transistors inside will not diffuse into randomness too soon. All are of the dust, and all turn to dust again.