1. Presentation on SGS, Crystal Defects & Wafer Preparation Guided By MD. Mohiuddin Munna

2. #Group Members# Chinmoy Das (2010338012) Nazmul Hossain (2010338016) Niloy Bonik (2010338017) Sohel Rana (2010338033)

3. #Semiconductor Grade Silicon (SGS)# The highly refined silicon used for wafer fabrication. Also known as Electronic Grade Silicon. Has ultra high purity.

4. #Steps to obtaining SGS#

5. Obtaining MGS

6. #Steps to obtaining SGS# Pure Silicon Producing System

7. #Crystal Defects in Silicon# Interruption in the repetitive nature of the unit cell crystal structure. Aiso known as micro defect.

8. #Types of Defects# Point Defects: Localized crystal defect at the atomic level. Dislocations: Displaced unit cells. Gross Defects: Defects in crystal structure.

9. #Point Defects# Vacancy Defect Interstitial Defect Frenkel Defect

10. #Vacancy Defect#

11. #Interstitial Defect#

12. #Frenkel Defect#

13. #Dislocations#

14. #Gross Defects#

15. #Wafer Preparation# A process of preparing wafer including- Machining operations Chemical operations Surface polishing & Quality measures.

16. #Basic Process Flow#

17. #Steps’ Introduction# Crystal Growth Shaping Wafer Slicing Wafer lapping & edge grind Etching Polishing Cleaning Inspection Packaging

18. #Shaping Operations# End Removal Diameter Grinding

19. #Wafer Slicing#

20. #Wafer Lapping# Two-sided lapping operation to remove damage left by slicing. Performed under rotational pressure with pads & mixture of alumina or silicon carbide & glycerin.

21. #Edge Contour#

22. #Etching#

23. #Polishing#

24. #Cleaning# Wafers must be cleaned to achieve an ultraclean state. Wafers should be free of particles & contamination.

25. #Wafer Evaluation# Wafers need to be inspected carefully before packaging. Standard quality should be measured.

26. #Packaging# Finally wafers should be packaged carefully.

27. Here is the END of our presentation Thanks everyone for being with us