Group 5 by EZZA SYUHADA BINTI SAZALI FS A https://padlet.com/ezzasyuhada/week3group5 en-us 2017-10-06 12:49:41 UTC 2023-04-12 06:54:08 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Moderncam.png B R I D G M A N - S T O C K B A R G E R T E C H N I Q U E https://padlet.com/ezzasyuhada/week3group5/wish/194952396
          WHAT IS IT?
Heating polycrystalline material above its melting point & slowly cooled from one end of its container (crystal seed located)

STOCKBARGER'S WAY?
Pulling method (Czochralski) , boat pulled out through temperature gradient

     BRIDGMAN'S WAY?
Melt it inside a temperature gradient furnace

            THE PRO?
Crystal shape defined by its container

          THE CON?
Material constantly in contact with sample boat which possibly changes ideal crystal structures caused by mechanical stress

        HOW TO DO IT?
Refer to the gif below :
]]> 2017-10-08 01:44:12 UTC https://padlet.com/ezzasyuhada/week3group5/wish/194952396 Float Zone https://padlet.com/ezzasyuhada/week3group5/wish/194952500 First foremost:
1. Mounted polycrstalline rod inside chamber
2.2cm rod is melted by RF
3.coil is then stabilized the liquid in molten zone
4.Lastly, the coil is moved along with molten zone through the rod
5. molten zone purified the rod and form single crystal
6. dopants and impurities rejected


]]> 2017-10-08 01:47:30 UTC https://padlet.com/ezzasyuhada/week3group5/wish/194952500 CZOCHRALSKI ( CZ ) CRYSTAL GROWTH https://padlet.com/ezzasyuhada/week3group5/wish/194952668 Principle
- Crystal pulling technique from the melt
- Based on a liquid to solid phase transition

Example
- Silicon, germanium, gallium arsenide,

Description and Working
- Large, single crystals of Si are grown by the CZ method
- It involves growing a single crystal in got from the melt, using solidification on a seed as illustrated.
- Gas inside the chamber is evacuated.
- Chamber is back-filled with an inert gas.
- Molten Si is held in a quartz crucible in a graphite susceptor
- It is heated by radio frequency induction coil
- A small discolation: free crystal, called a seed is moved down to touch the melt and then slowly pulled out of the melt.
- Dopant impurity is added:change into n-type and -type.

Advantages
- Growth from free surface
- Growth of large oriented single crystal
- Convenient chemical composition
- Control at atmosphere

Limitations
- High vapor pressure materials
- Liquid phase encapsulation
- Possible contanmination of the melt by the crucible
- No reproductivity of the crystal shape]]> 2017-10-08 01:53:28 UTC https://padlet.com/ezzasyuhada/week3group5/wish/194952668 https://padlet.com/ezzasyuhada/week3group5/wish/195730190 2017-10-10 17:29:32 UTC https://padlet.com/ezzasyuhada/week3group5/wish/195730190