According to history a new technology node is released every 2 years. Starting in 1971 with 10um technology node and with already some early projects in 7nm technology node, the semiconductor industry have invested heavily to develop those technology nodes that enable essentially faster, cheaper, smaller chips.
Technology node is essentially the physical size of the transistor- e.g the smaller the transistors, the more transistors in the same area, the faster they switch, the less energy they require and the cooler the chip runs.
Until 2009, technology node refer to the length of the silicon channel between the source and drain terminals in field effect transistors . For example, in a 130nm process, the length of the channel are 130 nm, but since 2009 the description of technology node changed.
The following table shows the different technology nodes half-pitch and gate length, the table is based on IEEE report.
