18-615 Micro and Nano Systems Fabrication
 


    


    
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About
    this course


    
This course is concerned
    with microfabrication technology interpreted broadly to include silicon integrated circuits, compound semiconductor technology, MEMS, AMLCD panels, disk drive heads, ...etc. It will be of interest to students performing
    research in the general area of solid-state devices and technology;
    to students in ECE, Physics, Materials Science and Engineering,
    and Chemical Engineering who wish to learn about microfabrication technology; and to advanced undergraduates, especially those pursuing
    the Electronic Materials minor.


    
This course will begin with a summary of unit process steps and a review of some actual process sequences. Much of the course will be devoted to a discussion of the physics, chemistry, and materials science behind individual process steps. The objective is to give students a useful introduction which goes beyond a qualitative description. In general each topic area will begin with qualitative discussion and will usually but not invariably continue to a discussion of fundamentals. Usually I will conclude with some discussion of current issues and trends. 
A basic understanding of semiconductor device physics
    (at the level of 18-310) or MEMS device physics (level of 18-614) will be assumed. Important process
    steps will be discussed with varying degrees of detail, including
    photolithography, etching, plasma deposition, metal deposition,
    diffusion, CVD/ epitaxy, and ion implantation. This is not a course on process simulation. Students should be prepared to use computation
    software of some sort in solving homework assigments. Mathcad
    is my current favorite, and I may post useful worksheets on the
    web which will faciliate homework assignments for those who choose
    to use this program. Homework assignments and other announcements
    will appear on the course website, and nowhere else (there will
    be minimal distribution of paper copies in this course).


    
I will post .pdf or .zip files
    of lecture materials and other supplementary material on this
    website. There will often be copyrighted material in these postings;
    consequently files will be protected by a password which will
    be announced in class. I believe that posting this material in
    password-protected form is permitted as a "fair use."
    By downloading such files you agree not to distribute these files
    and to reserve them for your own personal use.


    
Some lectures will have
    a substantial "blackboard" component. I will not provide
    notes from this part of the class.


    
Posted files may be
    large, and consequently they may not remain on the website for
    the entire semester. It is advisable to print/ review/ save these
    materials within two weeks of posting.
This course includes a laboratory. Completion of all laboratory assignments and reports is required. After the fact makeups will be arranged only in the most exceptional circumstances. (Admission to a hospital, etc.)
This course has other required assignments as detailed below. 


    
Course Objectives


    
      
  • Develop an understanding
      of the fundamental physics, chemistry, and materials science
      behind micromicrofabrication and to relate this to specific processes.
      
  • Gain an appreciation
      of practical aspects fabrication.
      
  • Develop the ability
      to do first-pass calculations using simple models and the insight
      necessary to distinguish plausible results from implausible ones.
      
  • Obtain an appreciation
      of important issues in process integration, manufacturing,
      process development, and process control.
    
    • 

    
    Personnel
    

    
    
      
    Prof. D.W. Greve 

    
      REH231
    
      dg07(at)andrew.cmu.edu

    
      X8-3707
    Chun Wang  chunw(at)andrew.cmu.edu
    Eric Black  rugal(at)cmu.edu
    

    
    Schedule
    

    
    
      
    Lectures: Tu,Th 3:00-4:20 WEH5310
    Lab: to be determined
    
    
    

    
    Text
    

    
    
      
    No text is required. However: tests will be open book and handwritten notes and homework solutions, with "book" restricted to one of the books discussed below (any edition). No, you can't share with your neighbor during tests. 
    If you WANT to use a book during the tests you are responsible for acquiring it. Requests to borrow a book the day before the test will be politely declined.
    Silicon VLSI Technology, J.D. Plummer, M. Deal, and
      P.B. Griffin, Prentice Hall, 2000 (ISBN 0-13-085037-3).
    Lead author has published very widely on semiconductor processing; very strong on diffusion and oxidation, a real textbook. Highly recommended.
    The Science and Egineering of Microelectronic Fabrication, S.A. Campbell, Oxford, 2001, Second edition, (ISBN 0-19-513605-5.
    Another real textbook with problems and good exposition. Highly recommended.
    Silicon Processing for the VLSI Era, Vol. 1 Process Technology, S. Wolf and R.N. Tauber, 2000, Lattice Press, (ISBN 978-0961672164).
    Essentially self-published with less polished production values. However this is highly regarded for its comprehensiveness although not necessarily linear in development. Long book, longer than the two above. Encyclopedic. Well-worn copies found on the bookshelves of a great many engineers in industry (along with the companion volumes 2-4 on related topics).  
    Microchip Manufacturing, S. Wolf, 2004, Lattice Press, (ISBN 978-0961672164)

    Illustrations in color! Short! Less comprehensive than the "big books" by the same author. Only the most important equations are given and with no development. Winner of the award for Most Hyphens in a Textbook Published in 2004. 
    Introduction to Microelectronic Fabrication, R.C. Jaeger, Second edition, 2002, Prentice Hall, (ISBN 0-201-44494).
    Paperback. The low cost solution. A perfectly good book for this course. From the lamented Blue Book series now out of print; famed for containing enough but not too much. If you go to industry you will have to buy a copy of Wolf and Tauber later. 
    

    
    Laboratory
    Organization of the laboratory is in progress. Check back for introductory and safety-related material, lab assignments, report template, etc. 
    Assignments, policies,
    etc.
    

    
    There will be homework assignments from time to time. A few of
    these will require access to a computer for numerical calculations. These will be graded on
    a pass/ fail basis with one opportunity granted to correct your
    solution if seriously wrong (albeit with an adverse impact on
    your grade). It is expected that all students will complete essentially
    all assignments correctly in a timely manner. Two tests are planned with tentative dates as shown in the schedule. 
    

    
    The time required for
    this course will be in line with the credit hours (that is, neither
    homework assignments nor the lab will require a committment
    of time which will prevent students from making progress on their
    research projects).
    Lectures. There will be lectures. Probably not quite as many as available (I count 27 lecture days after allowing for two tests) but more than last time this course was offered (as 18-815, 17 lectures). So expect a lecture or three to be cancelled. Stay alert. 
    

    
    Carnegie Mellon permits
    an instructor to determine the requirements for a student to
    receive a grade of "AU." I will issue a grade of AU
    provided a student certifies in writing or by email that he has attended
    at least 75% of the classes in this course.
    

    
    Approximate Outline
    

    
      
      
    1. Introduction to course; review of important unit processes; the lab process flow; mass production, FET scaling and the FET as a technology driver; yield quantification and some processes in varying degrees of detail. 
      
    2. Oxidation: technology; nature of SiO2; oxide growth kinetics; the Si-SiO2 interface; how are we going to replace SiO2?? A little bit about the silicon wafer itself.
      
    3. Wet etching: etchants for common materials; deionized water and liquid equilibria; etching mechanisms.
      
      
    4. Vacuum technology and the nature of gases; the glow discharge; mechanism of sputtering; DC, RF, magnetron sputtering; step coverage; trace gases and their possible incorporation into growing films.
      
    5. More about gases. Gas phase reactions and the determination of the equilibrium state. Gas flow and boundary layers.
      
    6. Epitaxy: what it is
      and why we want it; hetero- and homo-epitaxy. Epitaxy in the high-temperature regime: relevance of the equilibrium state; gas phase transport, surface reactions and growth kinetics.
    7. Epitaxy in the low-temperature limit: UHV/CVD, GSMBE, MBE, and other acronyms. Surface reaction kinetics and contamination (again). 
    8. Low pressure chemical vapor deposition: materials, chemistries, factors influencing growth kinetics and structure, especially of polysilicon. 
    9. Lithography: process
      outline; summary of photoresist chemistry; essentials of optics;
      photoprinters: contact, proximity, projection, stepping, e-beam,
      X-ray; masks: conventional and phase-shifting; substrate effects;
      the astonishing, continuing, and ultimately doomed dominance of optical lithography.
      
    10. Impurities and doping: dopant choice and incorporation limits; development of the diffusion equation; a formal solution to the diffusion equation; two particular solutions to the diffusion equation; profiles, interactions, and some words about simulation.
      
    11. Implantation: selecting and accelerating ions; stopping of ions and the resulting profiles; damage and annealing of damage; interactions with oxidation and diffusion.
      
    12. Metallization: metals and semiconductors in contact; equlibrium again (the phase diagram); silicides; metallization schemes; series resistance associated with contacts.
      
    13. Some more process flows, chosen for diversity and interest; process integration.
    

    
    Grading
    

    
      
      
      
        
      20% homework
        
      40% test
        
      40% lab
      
      
    
    Schedule 
    

    
    Tentative only.