Minimum structure size
The minimum feature size ( English minimum feature size is) a unit length (symbol: F) in the manufacture of semiconductor devices . It describes the value of the smallest structure that can be reliably produced by photolithography . As a rule, half the pitch of a periodic line structure is used as a reference structure for the determination.
Since the shape and composition (the design) of semiconductor elements and functional groups largely does not change, only the manufacturing technology, the size is given in multiples of the smallest unit (e.g. an SRAM memory cell with approx. 140 F² and a DRAM Memory cell with approx. 6–10 F²).
In addition to the absolute size of elements, the minimum structure size for naming a new technology node , e.g. B. 28 nm technology nodes or 28 nm technology. However, the reverse is not necessarily possible, as the continuous improvement of the manufacturing techniques of a technology node makes it possible to manufacture smaller structures. In practice, however, a circuit design is only gradually scaled down in the form of a technology node (reduction by a factor of 0.7) or a pseudo-technology node. Up until the late 2000s, this was associated with the introduction of new manufacturing techniques that made it possible to reliably manufacture smaller structures. From the 28 nm technology node and the introduction of FinFETs and other transistor designs, this assignment has become more difficult or unclear.
See also: Structure size
literature
- Chris Mack: Fundamental principles of optical lithography . Wiley-Interscience, 2008, ISBN 978-0-470-01893-4 , pp. 9-11 .
Individual evidence
- ^ Dean A. Klein: The Future of Memory and Storage: Closing the Gaps Microsoft WinHEC 2007.