In wafer technology, the choice of crystal growing method depends on the physicochemical properties and desired structural of the material, the economic aspect of the process is also important.
Monocrystals used for electronics can be obtained:
- From the solid phase, as a result of the solid state phase conversion,
- From the liquid phase, by direct solidification of the liquid, evaporation, through “drawing” a single crystal from molten material,
- From the gas phase, through sublimation, by gas chemical transportation.
The most common technique in a wafer production in a large scale is crystal growth form melt.
|Crystal growth rate : 10 ÷ 50 mm/h
Growth from the open area
Large scale production capability – large crystals
The possibility of achieving high crystal purity up to 99.999999999%
Obtaining a product with a certain crystallographic orientation
Wide range of application techniques – can be applied to many types of material
|Magnetic field applied Czochralski (MCZ)||Allows to obtain a larger crystal diameter than basic Czochralski method, is possible to control the flow of convection fluid and reduce the concentration of oxygen|
|Double Crucible CZ (DCCZ)||High homogenity for solid solutions|
|Vertical Bridgeman (VB)||Crystals are characterized by very low density of dislocation because of large thermal stresses|
|Kyropolos||Perfect for materials with a high thermal expansion and a low thermal conductivity|
|Heat Exchanger (HEM)||Inverted or modified Kyropoulos method,
using in production of sapphire wafers
|Verneuil||Flame-fusion growth process|
Float Zone (FZ)
|The material is cleaned by repeated passage through the zone
Crystals can grow in closed ampules or in open tanks
The process does not require great care
Simplicity: there is no need to control the shape of the crystal
|Edge-Defines Film-Fed Growth (EFG)||Ability to produce various shapes, material can be produced in different crystallographic orientations|
More services : Grinding, Dicing, Polishing, Etching, Bonding.