Inventions that Enabled the Silicon Age

Silicon-based electronic devices are all-pervasive, though this might have been unimaginable just a few decades ago. Their manufacture requires silicon with extreme purity, with less than one foreign atom per ten million of silicon. There are innovative processes that have enabled the mass production of such silicon. The base for discussion is the silicon that has been made since the nineteenth century for metallurgical applications, where the demands on purity are much less onerous. This is followed by the story of pure silicon crystals with minimal defects in their periodic structure, essential in the making of reliable semiconducting devices that are so remarkably affordable, so much so that there are now 56 billion transistors in existence per living person.