Boule (crystal)

A boule is a <a href="/facts/Single_crystal/UMG5pFp9">single-crystal</a> <a href="/facts/Ingot/j7kzdag2">ingot</a> produced by synthetic means.
A boule of <a href="/facts/Silicon/cgWx0hdr">silicon</a> is the starting material for most of the <a href="/facts/Integrated_circuit/fjn6vg7C">integrated circuits</a> used today. In the <a href="/facts/Semiconductor/zFf3mGTE">semiconductor</a> industry synthetic boules can be made by a number of methods, such as the <a href="/facts/Bridgman_technique/G8ekXBI0">Bridgman technique</a> and the <a href="/facts/Czochralski_process/uvSrr84x">Czochralski process</a>, which result in a cylindrical rod of material.
In the Czochralski process a <a href="/facts/Seed_crystal/WxJ17hXh">seed crystal</a> is required to create a larger crystal, or <a href="/facts/Ingot/j7kzdag2">ingot</a>. This seed crystal is dipped into the pure molten silicon and slowly extracted. The molten silicon grows on the seed crystal in a crystalline fashion. As the seed is extracted the silicon solidifies and eventually a large, cylindrical boule is produced.
A semiconductor crystal boule is normally cut into circular <a href="/facts/Wafer_(electronics)/lCBJAoUL">wafers</a> using an inside hole <a href="/facts/Diamond_saw/QLABehU4">diamond saw</a> or diamond <a href="/facts/Wire_saw/XyTRQ2su">wire saw</a>, and each wafer is <a href="/facts/Lapped/CXVRF336">lapped</a> and polished to provide substrates suitable for the fabrication of <a href="/facts/Semiconductor_device/6W3ryr50">semiconductor devices</a> on its surface.
The process is also used to create <a href="/facts/Sapphire/C11GJAmm">sapphires</a>, which are used for substrates in the production of blue and white <a href="/facts/Light_emitting_diode/gE8x4MDb">LEDs</a>, optical windows in special applications and as the protective covers for <a href="/facts/Watches/PuFUMNTl">watches</a>.

Boule (crystal) open-in-new

Boule (crystal)