How extrinsic p-type semiconductor can be form ?

Answer 1

Take a 'virgin' intrinsic silicon crystal wafer, place it in a vacuum chamber, and bombard it with boron ions, or aluminum ions.

It would be useful if a mask was used to direct where you want the ions to go (and block where you don't want them to go). Depending on the ion current and energy, and the depth to which you want the p-type material to be formed in the intrinsic crystal lattice, you must time the bombardment. The longer you fire ions into the silicon, the deeper the p-type material you will have.

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Answer 2

conductors when they are pure serve heights;semi-condutors impure 13 bred through very low grade alloys 1 may be better than the other but both do not pass high standards for purity.

Answer 3

http://en.wikipedia.org/wiki/Extrinsic_semiconductor