The manufacture of nanoelectronics components.
The starting point is a wafer (a round thin disk, usually of silicon). After cleaning and rinsing the wafer meticulously, several hundreds of separate microelectronic components (chips) are built step by step, layer on layer on the wafer. At each step of this process, the wafer is tested with specially designed equipment under computer control.
When the process is completed, all the chips on a wafer are individually tested again. Those that pass the rigorous electrical tests are then cut from the wafer with high-speed, water-cooled, diamond cutting saws and mounted in metal or plastic packages, called modules. These modules are then tested again.
The primary building blocks on the wafer are the transistors, i.e. tiny switches that by being off or on signal 0 or 1 – the basis of all digital systems. The next level building block is the integrated circuit (IC). An IC is composed of several components of various types – transistors, diodes, resistors, and capacitors. These are wired into a specific circuit having a specific function. An IC can consist of as few as two components up to hundreds of billions of components. Soon the technology for making ICs will probably be able to put hundreds of trillions of components in one IC. As the components get smaller, the demand on the purity of the rinsing water increases.