Download presentation

Presentation is loading. Please wait.

Published byReilly Vital Modified over 4 years ago

1
Presentation on Semiconductor Fundamental Submitted by : MD. Jubayer Ahmed MD. Mehedi Hasan Tanvir Anjum A.S. Shakur Submitted to: Mohiuddin Munna Lecture Dept. of EEE SUST, Sylhet. Shahjalal University of Science & Technology, Sylhet. Dept. of Electrical & Electronic Engineering. 2010338025 2010338019 2010338007 2010338013

2
Structure : The atomic arrangement within a solid can be classified as follows Amorphous Polycrystalline Crystalline

3
Amorphous: An Amorphous solid is a material in which there is no recognizable long-range order in positioning of atoms within the material. Crystalline: A crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an ordered pattern extending in all three spatial dimensions.

4
Polycrystalline: Polycrystalline materials are solids that are composed of many crystallites of varying size and orientation.

5
Unit cell Unit cell: The unit cell is a small box containing one or more atoms arranged in 3-dimensions

6
The unit cell is represented in terms of its lattice parameters.

7
On the cubic category there are three types of unit cells Simple cubic Body-centered cubic Face-centered cubic

8
Silicon Lattices In Si (and Ge) the lattice structure is diamond lattice. Diamond Lattice: 1.Similar to F.C.C but have four additional atoms. 2.Most of the iii-v semiconductors are diamond lattice. 3.Diamond lattice similar to zincblende structure.

9
Fig: silicon lattice

10
Fig: Diamond LatticeFig: Zincblende Structure

11
MILLER INDICES The position of the planes or the direction of a vector in the lattice are usually described by three integers.

12
HOW TO FIND MILLER INDICES. Determine the intercepts of the plane intersecting the xyz coordinate.a1 – x direction, a2 – y direction, and a3 – z direction. Take the reciprocals of the intercepts. h = 1/a1, l = 1/a2, and m = 1/a3. Reduce the result to the smallest integer. ( hkl) – for single plane and {hkl} for a group of planes. Negative Miller values are denoted by a bar on top. Example - (ħkl). Planes without an intersecting intercept are taken as infinite planes (∞).

13
Obtaining Ultrapure Si: In nature Si is found in a various forms of silicon dioxide or silicates. silicon the second most abundant element in the Earth's crust (about 28% by mass) after oxygen. Czochralski process.

15
Thank You

Similar presentations

Presentation is loading. Please wait....

OK

Structure of Solids Chapter 11 Part III.

Structure of Solids Chapter 11 Part III.

© 2018 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google