Editing Ion implantation (section)

===Ion channelling===
[[Image:Diamond structure.png|thumb|right|300 px|A diamond cubic crystal viewed from the [[Crystallography#Notation|<110>]] direction, showing hexagonal ion channels.]]

If there is a crystallographic structure to the target, and especially in semiconductor substrates where the crystal structure is more open, particular crystallographic directions offer much lower stopping than other directions. The result is that the range of an ion can be much longer if the ion travels exactly along a particular direction, for example the <110> direction in [[silicon]] and other [[diamond cubic]] materials.<ref>{{Cite book|title=Materials science of thin films : deposition and structure|author=Ohring, Milton|date=2002|publisher=Academic Press|isbn=9780125249751|edition=2nd|location=San Diego, CA|oclc=162575935}}</ref> This effect is called ''ion channelling'', and, like all the [[Channelling (physics)|channelling]] effects, is highly nonlinear, with small variations from perfect orientation resulting in extreme differences in implantation depth.  For this reason, most implantation is carried out a few degrees off-axis, where tiny alignment errors will have more predictable effects.

Ion channelling can be used directly in [[Rutherford backscattering]] and related techniques as an analytical method to determine the amount and depth profile of damage in crystalline thin film materials.