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					Defects and Disorders
 in Semiconductors

Jermell Powell
ECE 423
11/15/06
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Defect types
 Point defects
 Line defects
 Area defects
 Cluster defects
                        3




Point defects
 Types
 Frenkel defect pair
               4




Line defects
   Example
                          5




Wide defects
   Area defect
     Epitaxial   mound

   Cluster defect
     Dustparticle
     Mask scratch
                                                 6




Defect density
   d(r) = d{1 + 2.5 exp [0.34 X 19(1 - r/R)]}
                           7




Causes of defects
   Semiconductor doping




   Czochralski method
                          8




Advanced defects
   Antisite
     Nonstoichiometric

   Void defects
                                   9




Divacancy
 Cause
 Effect
     V-V +   Isi -> V-V + Isi
     V-V +   Isi -> V
     V-V +   2Isi -> V-V + 2Isi
     V-V +   2Isi -> V + Isi
     V-V +   2Isi -> 0
                             10




Results
   Positive
     Oxygen   in Silicon
        Lifetimes
        Diffusion lengths

        Mobilities

        Solar cells, IC
                          11




 ZnTe   and CdTe
   Chlorine doping
   Copper doping

 GaAs,   Arsenic heavy
                                     12




   Detrimental
     Categories  of Inoperability
     Oxygen in Silicon
     Dielectric breakdown
                13




Questions?
   Thank you

				
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