Editing Wafer (electronics) (section)

=== Crystalline orientation ===
[[File:Silicon-unit-cell-3D-balls.png|thumb|Diamond cubic crystal structure of a silicon unit cell]]
[[File:Wafer flats convention v2.svg|thumb|Flats can be used to denote [[doping (semiconductors)|doping]] and [[crystallography|crystallographic]] orientation. Red represents material that has been removed.]]

Wafers are grown from crystal having a regular [[crystal structure]], with silicon having a [[diamond cubic]] structure with a lattice spacing of 5.430710 Å (0.5430710&nbsp;nm).<ref name="HandbookSi">{{cite book|last=O'Mara|first=William C.|url=https://books.google.com/books?id=COcVgAtqeKkC&q=Czochralski+Silicon+Crystal+Face+Cubic&pg=PA351|title=Handbook of Semiconductor Silicon Technology|publisher=William Andrew Inc.|year=1990|isbn=978-0-8155-1237-0|pages=349–352|access-date=2008-02-24}}</ref> When cut into wafers, the surface is aligned in one of several relative directions known as crystal orientations. Orientation is defined by the [[Miller index]] with (100) or (111) faces being the most common for silicon.<ref name=HandbookSi/>
Orientation is important since many of a single crystal's structural and electronic properties are highly [[anisotropic]]. [[Ion implantation]] depths depend on the wafer's crystal orientation, since each direction offers distinct [[Ion implantation#Ion channelling|paths]] for transport.<ref>{{cite book|last=Nishi|first=Yoshio|url=https://books.google.com/books?id=Qi98H-iTgLEC&q=wafer+flat+and+notch&pg=PA70|title=Handbook of Semiconductor Manufacturing Technology|publisher=CRC Press|location=Boca Raton, Florida|year=2000|isbn=978-0-8247-8783-7|pages=108–109|access-date=2008-02-25}}</ref>

Wafer [[cleavage (crystal)|cleavage]] typically occurs only in a few well-defined directions. Scoring the wafer along cleavage planes allows it to be easily diced into individual chips ("[[Die (integrated circuit)|die]]s") so that the billions of individual [[Electronic component|circuit elements]] on an average wafer can be separated into many individual circuits.{{Citation needed|date=February 2021}}