Portland Community College | Portland, Oregon

This is Part III of the three course series on semiconductor process equipment. Part I (MT224) covers the individual components of process equipment (controllers, sensors, motors, etc.) Part II and III cover process equipment as a whole system. The LAM Rainbow etcher system is used as a typical example of a fab process system. Students will learn operations, theory of how various subsystems of the system function, maintenance procedures, and trouble shooting of the etcher. 

Students in this course are expected to be able to carry out independent research in order to discover the components and functions of the etcher system. They are also expected to be able to integrate their knowledge gained in MT224, MT240, and MT223 to gain insights into the etcher system.

Upon completion of the course students should be able to:

• Apply an understanding of industrial equipment to analyze the functions of highly automated industrial equipment used in semiconductor or other industries.
• Apply a good foundation in maintenance to perform basic industry standard maintenance procedures.    
• Troubleshoot basic problems of certain subsystems of highly automated industrial equipment used in semiconductor or other industries following a systematic methodology.

The course 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. Students will perform independent research, preventative maintenance, and trouble-shooting in class. Students may be required to come to the lab after school to work in groups on equipment as a part of homework.

Assessment of student performance in this course will be in the form of written and/or practice-based questions. Some formal reports and presentations are required also.

REQUIRED STUDENT COMPETENCIES:
1.0 Wafer Transfer System Alignment (week1, 2)
1.1 Understand the degrees of freedom a rigid body can have in 3 dimensional space, i.e. displacement freedom along x, y, z axis and rotation around x, y, z axis. Understand the alternative polar coordinate system of r, theta, and height.
1.2 Be able to read and understand conceptually a typical alignment procedure between two components of the wafer transfer system—the sender and the receiver (example: transfer of wafer from cassette indexer to the shuttle arm of the Lam etcher) following the methodology below:
Step1: Identify degrees of freedom the system has.
Step2: Identify in which degrees of freedom, adjustment is necessary.
Step3: Identify what mechanism the equipment uses to adjust alignment in each degree of freedom.
Step4: Find out the order of alignment—which degree of freedom of the system needs to be aligned first, second, …etc.
1.3 Upon reading Lam alignment procedure, be able to organize individual steps into groups to better organize and understand the steps of the procedures. (i.e. step 1-4 may all describe adjustment of height and leveling)
1.4 By reading schematics and by observing the operations of an actual piece of equipment, be able to develop an alignment procedure for the equipment following the methodology above.
1.5 Be able to perform alignment procedures described in the Lam etcher manual.
1.6 While performing the alignment procedure, be able to use observation of relevant indicators as a feed-back to judge whether the alignment is off in certain dimensions.

2.0 Process Chamber (week 3-5)
2.1 Understanding of the components of the process chamber and its subsystems—upper electrodes, lower electrodes*, and the gap drive. (*lower electrode is optional this year)
2.1.1 Be able to read a cross sectional or exploded view schematic and discern the various parts of a subsystem and discern their spatial relations
2.1.2 Be able to locate the components on the etcher with the aid of a schematic
2.1.3 Describe the function that each component performs.
2.1.4 Describe the major functions of the process chamber. Be able to discover and then describe how the functions of the process chamber as a whole are achieved by the functions of the individual components. The major functions of the process chamber should include: RF delivery, gas delivery, pressure control, temperature control including He cooling and wafer clamping, gap distance control and end point detection.
2.2 Understand how process parameters affect processes which occur during etch, and in turn etch properties (such as etch rate).
2.3 Preventative Maintenance (PM):
2.3.1 Be able to perform the following Preparation Procedures:
P1: Automatic chamber vent
P2: Manual chamber vent
2.2.2 Be able to perform the following verification procedures:

V1. Rate of rise check
V2. Upper electrode centering
2.2.3 Be able to perform the following upper electrode PM procedures:
U1. Confinement ring removal and replacement
U2. Clamp/ plunger attachment plate removal and replacement
U3. Upper electrode removal and replacement (including upper electrode centering)
2.2.4 *Be able to perform the following lower electrode PM procedures: (*optional this year)
L1. Lower clamp removal and replacement (including lower clamp centering)
L2. Lower electrode removal and replacement (needs to perform lower clamp centering)
2.2.5 * Be able to perform chamber clean PM procedure (*optional this year)
2.2.6 Demonstrate good PM practices while performing the above PMs (for example, lay out parts in advance of PM, noting how to put things back while taking them apart)
2.2.7 Demonstrate good PM strokes while performing the above PMs (for example, holding both sides of ranches so as not to damage the electrode)
2.2.8 Be able to understand a PM by reading spec. Be able to dissect a complex PM procedure into simpler blocks.
2.2.9 Be able to come up with the right sequence of steps to perform in a related hypothetical PM (example, rate of rise of ELL).

3.0 Vacuum System (week 5-6)
3.1 Understanding of the components of the vacuum system
3.1.1 Be able to identify the various components of a subsystem and discern their functions by inspecting and observing the subsystem by eye. Subsystems should include: process chamber, ELL, and XLL.
3.1.2 Be able to draw a schematic of how the various components are linked with each other in a subsystem.
3.1.3 Describe the major functions of a subsystem. Be able to discover and then describe how the functions of the vacuum system as a whole are achieved by the functions of the components. The major functions of the vacuum system should include: venting, purging, pump down, and pressure control.
3.2 Be able to read a flow diagram of the process gas delivery system and discern how gases are flown into the chamber
3.3 Given a diagram, show the valving sequence to get a process gas to flow into the chamber.
3.4 Be able to design the right sequence of events to achieve certain task of the etcher (example, vent ELL manually)

4.0 Trouble-shooting (week 7, 8, 9, 10)
4.1 Be able to form an objective problem statement
4.2 Be able to form a clear mental picture of the entire system involved in the problem
4.3 Be able to design and then carry out quick and definitive tests to isolate the problem to a subsystem.
4.4 Be able to make a list of all possible causes of the problem in this sub-system.
4.5 Be able to design quick and definitive tests to verify whether a possible cause is the true cause or not.
4.6 Be able to prioritize to see which possible causes to check first based on the ease of the check and the probability of the cause
4.7 Be able to gather and use clues to judge which path to follow. (Given the clues, what is the likely cause? Training of this judgment)