MECH466-Lecture-3 - 1 MECH 466 Microelectromechanical...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 MECH 466 Microelectromechanical Systems University of Victoria Dept. of Mechanical Engineering Lecture 3: Basic Concepts: Semiconductors May 14th, 2007 Mech 466, N. Dechev, UVic 2 Silicon Structural Properties Crystal Planes Bulk Micromachining Semiconductor Properties Doped Semiconductors Overview Mech 466, N. Dechev, UVic 3 Silicon Structural Properties Silicon solid exists in three different forms: Amorphous Randomly oriented atoms, e.g. Glass Polycrystalline Crystal grains/ domains oriented in random directions, which meet at grain boundaries Crystal Entire solid is made of an ordered array of atoms Mech 466, N. Dechev, UVic 4 Silicon Structural Properties Silicon crystal lattice is cubic. Silicon atoms form covalent bonds with four adjacent atoms, in the form of a diamond lattice structure. Si Atoms Covalent Bonds Note: Bonds outside of Cubic Lattice are not shown Mech 466, N. Dechev, UVic 5 Silicon Structural Properties Silicon exhibits different properties along different crystal planes. Properties such as E (youngs modulus), electron mobility, piezoresistivity, and chemical etch rates (for fabrication purposes). z x y a a a Mech 466, N. Dechev, UVic 6 Miller Indices, Planes The Miller Indices are a common notation used to identify the planes and directions in a crystal lattice. To determine the Miller Index of a plane, we use the following procedure: z x y a Step 0: Identify the plane of interest. For example, the plane shown in pink is one face of the cubic structure. Mech 466, N. Dechev, UVic Crystal Plane (100) Step 3: Reduce these numbers to the smallest set of integers h , k and l , by multiplying all by a , which yields (1 0 0). Parentheses are used to denote a crystal plane. Step 2: Take the reciprocals of the three numbers found in step 1. In this example: 1/ a , 1/ ! (=0), and 1/ ! (=0). Step 1: Identify the intercepts of the plane with the x , y and z axes. In this example, we have x = a , y = infinite, z = infinite....
View Full Document

This note was uploaded on 02/02/2010 for the course MECH 466 taught by Professor Dechev during the Summer '07 term at University of Victoria.

Page1 / 15

MECH466-Lecture-3 - 1 MECH 466 Microelectromechanical...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online