Editing wafer size

'''Wafer size''' refers to the diameter of a [[wafer]] and is an important parameter as part of the [[semiconductor manufacturing process]]. A larger wafer size enables the fabrication of more dice per wafer which translates into cost reduction in high-volume manufacturing.

== Motivation and difficulties ==
[[Wafer]] size has increased greatly over the years from 23 mm (0.905 of an inch) in [[1960]] to 300 mm in nowadays. [[Foundries]] make the transition to a larger wafer because of the cost benefits resulting from producing the larger number of [[dice]] per wafer, all while maintaining many of the same process steps to produce the them. Unfortunately increasing the wafer size is far from being a trivial process - costing billions in [[research & development]]. The transition to 300 mm in the early 2000 cost the industry $10s of billions<ref>ISMI</ref>. Most recently, the transition from 300 mm to 450 mm wafer will have an overall price tag of $25 to $40 billion<ref>G450C</ref> with other estimates that go as high as $100B. The monumental cost associated with the transition created considerable resistance in the industry fearing insufficient return on investment and incredible risk and uncertainty associated with the transition.

== Historical Sizes ==
{| class="wikitable"
|-
! Year !! Wafer size<ref>F450C</ref><ref>I300I</ref> !! Wafer thickness
|-
| 1960 || 23 mm || ?
|-
| 1962 || 25 mm || ?
|-
| 1963 || 28 mm || ?
|-
| 1969 || 51 mm || 275 µm
|-
| 1972 || 75 mm || 375 µm
|-
| 1976 || 100 mm || 525 µm
|-
| 1981 || 125 mm || 625 µm
|-
| 1983 || 150 mm || 675 µm
|-
| 1992 || 200 mm  || 725 µm
|-
| 2002 || 300 mm || 775 µm
|-
| ~2020 || 450 mm || ~925 µm
|}

Note that wafers grown using materials other than silicon have different thicknesses than a silicon wafer due to the different stress and strain properties. Wafers must be tick enough to maintain structural integrity during processing and handling.

== References ==
{{reflist}}