Module 3: Units of Pressure/Definition

Description: Introduces the various systems of units used to measure pressure and conversions between them.

Length of Time: 2 hours


1. Units of measure

a. Torr

b. Pascal

c. mbar

d. mm Hg

2. Conversions between pressure units

3. Pressure regimes (ranges)

a. Low vacuum

b. Medium vacuum

c. High vacuum

d. Ultra high vacuum

4. Pressure differential and net forces


Student Objectives:

Student will be able to:

1. Convert pressure from one system of units to another system of units.

2. Give the four different pressure ranges of vacuum systems: low, medium, high, and ultra high.

3. Explain the relationship of vacuum ranges to semiconductor processes, e.g. photolithography, etch, diffusion, deposition, ion implant, etc.


Chambers: Chapter 2 "Gases in Vacuum Systems"

O’Hanlon: Chapter 1 "Vacuum Technology"

Varian: Chapter 1 "Vacuum Fundamentals"

Chapter 2 "Roughing Pumps"