Course Content and Outcome Guide for MT 223

Course Number:
MT 223
Course Title:
Vacuum Technology
Credit Hours:
Lecture Hours:
Lecture/Lab Hours:
Lab Hours:
Special Fee:

Course Description

Covers the theory and practice of vacuum as used in semiconductor manufacturing. Topics include vacuum principles, vacuum systems and their components such as pumps, gauges and valves, and finally vacuum trouble- shooting. Prerequisites: MT 101, MT 102, (MT 103 or MT 104), CH 100 or higher, WR 121, or instructor permission. Audit available.

Intended Outcomes for the course

1. Apply basic vacuum principles such as the behavior of gas and behavior of a vacuum system while evaluating a pump down.
2. consider basic mechanisms and characteristics of vacuum system components such as pumps, valves and gauges while troubleshooting.
3. Be able to perform basic operations of a vacuum system such as measuring pressure correctly, venting a vacuum system, a rough pump down and a high vacuum pump down with correct valving sequence.
4. Be able to perform simple maintenance of vacuum systems including installation or replacement of various pipes, fittings, valves, gauges, and simple pumps.
5. Be able to perform vacuum trouble-shooting including leak isolation and detection.


Course Activities and Design

This course will include a variety of learning activities.  The
lecture portion of the course, three hours per week, will include
instructor delivered lectures and demonstrations stressing key
topics in the course.  In preparation for the lecture portion of
the course, students will be expected to complete all reading and
homework assignments.

The laboratory portion of the course, three hours per week, will
include laboratory activities.  The purpose of the laboratory
activities is to develop skills in the operation of basic vacuum
systems and analyzers, teamwork, and communicating in oral and
written form.

Outcome Assessment Strategies

Assessment of student performance in this course will be conducted
in both the lecture and laboratory portions of the course and may
be in the form of written and/or practice-based questions.

Course Content (Themes, Concepts, Issues and Skills)


1.0  Property of Gases

1.1  Define the terms: pressure and vacuum.

1.2  Convert pressure units between the following systems of
     units:  torr, pascal, mbar, atm, and mm of Hg.

1.3  State the following laws for pressure-volume-temperature
     relationships for a fixed amount of gas:
          (a)  Boyle's Law
          (b)  Charles' Law
          (c)  Gay-Lussac's Law

1.4  State the ideal gas law.

1.5  Solve for pressure, temperature, molecular mass, and volume
     of a gas using the ideal gas law.

1.6  State Avogadro's Principle for equal volumes of gases.

1.7  State Dalton's Law of Partial Pressure as it relates to a
     mixture of gases.

1.8  State Graham's Law of Effusion.

1.9  State the main ideas that form the basis for the Kinetic
     Theory of Gases.

1.10 Draw a graph to illustrate the distribution of kinetic
     energies in a collection of gas molecules at three different

1.11 List the gaseous components and percent composition of air
     (excluding water vapor as a component).

1.12 Define the term "Standard Temperature and Pressure" or STP.

1.13 Calculate the "mean free path" of a given gas at a given
     temperature and pressure.

1.14 List the four different pressure ranges of vacuum systems:
     low, medium, high, and ultra-high.

1.15 State the relationship of vacuum ranges to semiconductor
     processes, e.g. photolithography, etch,  diffusion, deposition,
     ion implant, and metallization.

2.0  Gas Flows

2.1  Define the following types of gas flows:  turbulent, viscous,
     intermediate, and molecular.

2.2  Relate the different types of gas flows to the following
     pressure regions:  low, high, and ultra-high.

2.3  Define the terms:  throughput and conductance.

2.4  Given a component catalog or data sheet, find the conductance
     value for a given vacuum system component.

3.0  Gas Sources

3.1  Define the following terms:  volume gas, surface gas, and

3.2. Give examples of where volume gases, surface gases, and
     monolayers occur in a vacuum system.

3.3  Relate surface gas composition variations to pumping time.

3.4  Define the term:  rate-of-rise.

3.5  Given pressure versus time data, construct a log-log graph
     describing rate-of-rise.

3.6  Define the term:  outgassing.

3.7  Identify materials that are the major sources of outgassing
     in vacuum systems.

3.8  Describe the effects of outgassing and contamination on
     vacuum system performance.

4.0  Low Vacuum Systems

4.1  Sketch and describe the mechanical operation of the following
     mechanical pumps:  rotary oil-sealed mechanical pump, dry pump,
     and lobe pump.

4.2  Define the term:  backstreaming.

4.3  List methods to eliminate or minimize backstreaming in
     mechanical pumps.

4.4  Give the operating pressure range and operating principle of
     the following low-vacuum gauges:  absolute pressure gauge,
     diaphragm gauge, capacitance manometer, thermocouple gauge and
     convection gauge.

4.5  Describe how each low-vacuum gauge is maintained.

5.0  High Vacuum Systems

5.1  Sketch and describe the operation of the following high
     vacuum pumps:  turbomolecular pumps,  cryo pumps, diffusion pumps,
     cryo panels and cryo traps, and getters.

5.2  State the operating pressure range for each pump listed in
     Objective 5.1.

5.3  Given a specific gas, select the pump that would produce the
     highest pumping speed.

5.4  Identify the components and describe the theory of operation
     of the following high vacuum gauges:  cold cathode ionization
     gauge and hot cathode ionization gauge.

5.5  List the limiting factors for high and low pressure limits
     for each type of gauge listed in Objective 5.4.

6.0  Leak Detection

6.1  Describe the liquid seal leak detection method.

6.2  Draw a block diagram of a leak detector indicating test
     manifold, isolation valve, accumulator or throttle valve,
     discharge gauge, mass spectrometer, roughing pump and high vacuum

6.3  Demonstrate troubleshooting skills by systematic leak
     detection using helium gas.

6.4  Relate leak rate to standard cc/sec.

6.5  Define the term:  virtual leak.

7.0  Residual Gas Analyzer

7.1  State the purpose of a residual gas analyzer.

7.2  Identify the major components of RGA's .

7.3  Describe the differences in mass filtering between a
     quadrapole and a magnetic sector RGA.

7.4  Analyze a mass spectrum in a typical vacuum situation.

8.0 Vacuum Components and Materials

8.1  Describe the operating principle and best usable pressure
     range of the following fittings:  O-Ring, Conflat flange, K-flange,
     and Swedgelock.

8.2  Describe the operating principles and correct operation of
     the following valves:  Regulators, Nupro pneumatic, needle valve,
     throttle value, swing gate, and sliding gate.

8.3  Describe basic lubrication processes, fluid rheology and
     techniques for vacuum lubrication.

8.4  Describe vacuum sealing and joining techniques:  welded and
     brazed metal joints, metal, glass and ceramic joints, elastomer
     and metal-sealed flanges, valves, and motion feedthroughs.