tech - Defects and Disorders in Semiconductors

Defects and Disorders in Semiconductors Jermell Powell ECE 423 11/15/06 1 2 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  Dust particle  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  + Isi -> V-V + Isi  V-V + Isi -> V  V-V + 2Isi -> V-V + 2Isi  V-V + 2Isi -> V + Isi  V-V + 2Isi -> 0  V-V 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 of Inoperability  Oxygen in Silicon  Dielectric breakdown  Categories 13 Questions?  Thank you