ºÝºÝߣ

ºÝºÝߣShare a Scribd company logo

Wafer fabrication

?Download as PPTX, PDF?
?
I
ImranAhmad225

This document discusses crystal growth and wafer fabrication processes. It first covers crystal structures and defects like vacancies and dislocations. It then describes the dominant Czochralski method for growing silicon crystals from melted polysilicon, noting important control parameters like pull rate and temperature. Finally, it mentions preparing the crystals into wafers through chemical mechanical polishing.

1 of 11
Downloaded 15 times
Crystal Growth and Wafer Fabrication Mr. Imran Ahmad Assistant Professor JETGI
Crystal Structure Crystals are characterized by a unit cell which repeats in the x, y, z directions.
Silicon Crystal Structure
Defects in Crystals I. Point Defects e.g. Vacancies (V), Interstitials (I) II. Line Defects e.g. Dislocations III. Area Defects e.g. Stacking Faults IV. Volume Defects e.g. Precipitates, Collection of Vacancies
Wafer fabrication
Czochralski Crystal Growth Method
1. Essentially all Si wafers used for ICs today come from Czochralski grown crystals. 2. Polysilicon material is melted, held at close to 1417 ¡ãC, and a single crystal seed is used to start the growth. Czochralski Crystal Growth Method 3- Pull rate, melt temperature and rotation rate are all important control parameters.
Wafer fabrication
Wafer Preparation
Chemical Mechanical Polishing (CMP) Process
Wafer fabrication

More Related Content

Wafer fabrication