Question

Drawo neat labelled diagram
of the Czochralski method
of growth and purification of
semiconduchor crystal.​

Answer 1

Answer:

Dissolve the Si in the crucible and keep its temperature close to the melting point. Since you cannot avoid temperature gradients in the crucible, there will be some convection in the liquid Si. You may want to suppress this by big magnetic fields.

Insert your seed crystal, adjust the temperature to "just right", and start withdrawing the seed crystal. For homogeneity, rotate the seed crystal and the crucible. Rotation directions and speeds and their development during growth, are closely guarded secrets!

First pull rather fast - the diameter of the growing crystal will decrease to a few mm. This is the "Dash process" ensuring that the crystal will be dislocation free even though the seed crystal may contain dislocations.

Now decrease the growth rate - the crystal diameter will increase - until you have the desired diameter and commence to grow the commercial part of your crystal at a few mm/second.

Answer 2

Answer:

see the attachment

Explanation:

hope it helps you