1. Solid State Synthesis Czochralski Method
Bridgman-Stockbarger Technique
Zone Melting Method
Flame Fusion Method (Verneuil Method)

2. 1. Czochralski Method 2m Crystal Rod Czochralski Puller
Melting of raw materials or dopants
Seed growth and crystal pulling
Cooling
2m Crystal Rod
Sliced Si wafer
Memory chips on si wafer
Czochralski Puller
■ Principle & Process
Crystal growth method to obtain semiconductors (e.g. Si, Ge, GaAs) and metals (e.g. Pd, Pt, Ag, Au).
■ Characteristics
Rod-shaped single crystal is obtained from a melt of the same composition of melt.
Very large crystal is obtained at once. (e.g. 50 kg silicon rod with the size of ~2 m and width of 30 cm)
Extremely little impurities. (< 0.01 ppb)
Drawback: Materials with high vapor pressure cannot be grown.
■ Usages & Applications
Production of highly pure metals, semiconductors, salts, and synthetic gemstones.
Mass production of silicon wafer
Dopants can be added to make p-type (Boron dopant) or n-type (Phosphorus dopant) semiconductors.

3. 2. Bridgman-Stockbarger Technique
Stockbarger method
Bridgman Furnace
Bridgman method
■ Principle & Process
Heating polycrystalline material above its melting point and slowly cooling it from one end of its container, where a seed crystal is located.
Stockbarger method: As a pulling method like Czochralski method, boat pulled out through temperature gradient
Bridgman method: Melt is inside a temperature gradient furnace
■ Characteristics
The shape of the crystal is defined by the container
Drawback: Material is constantly in contact with crucible or sample boat, which introduces mechanical stress that possibly changes ideal crystal structures.
■ Usages & Applications
Simple and popular way to producing semiconductor crystals such as GaAs, InP, CdTe)

4. 3. Zone Melting (Zone Refining) Method
Zone Refining Furnace
Heating coil
Unmelted region
Tantalum crystal (99.999% purity)
Tantalum capacitor
■ Principle & Process
Method for purifying crystals: Impurities concentrate in the melt, and move to one end of container.
Molten zone melts impure solid at its forward edge, and purer material is solidified behind it.
■ Characteristics
Pure solid can be obtained in a simple manner.
Drawback: Materials with high vapor pressure cannot be grown.
■ Usages & Applications
Preparing high purity materials, mainly semiconductors for manufacuturing transistor.

5. 4. Flame Fusion Method (Verneuil method)
Verneuil Furnace
Gemstones
Refined Sapphire
Unrefined Ruby Rod
■ Principle & Process
Precursor pass through flame and then melted into liquid
Melted droplets fall on surface and crystal grows on it.
■ Characteristics
Rod-shaped gemstone crystal is obtained.
Useful for materials with high melting points.
Drawback: Excess oxygen induces gas bubble which induces imperfection of solids.
■ Usages & Applications
- Growing crystals of metal oxides with high melting points, such as gemstones (ruby, sapphire, spinels..)