Materials Chemistry Laboratory CH 445/545 SB2 – B71 and SB2 401

Spring 2011 Professor: Shankar Rananavare TA: 503-725-8511 SB2 – 358 SB2 – 442 ranavas@pdx.edu Overview: This Lab is designed to give some experience working in semiconductor industry. You will be required to complete and write full lab reports for all of the lab- experiments. You will be working in groups. Please keep in mind you will need extra time for some experiment, the TA will setup schedule for you. The lists of experiments are listed below.

1. Photolithography software: PROLITH 2. Growth kinetic of oxide on silicon 3. Learn spin coating to fabricate thin films

• Viscosity polymer solution • Film thickness measurement using a reflectance spectrometer

4. Characterization of SPR photoresist • Determination of Dill’s parameter • Fabrication of the microstructures on silicon substrate using SPR

photoresist.

Textbook(s): There is no official textbook for this lab. Suggestive reading to better understanding the concept of microfabrication and electronic materials can be found in the textbook: Electronic Materials, by Nicholas Braithwaite and Graham Weaver. Also make use of the web, you can find information about the technique, discussion, calculations online. Also please read supporting materials on D2L web site. Notebook: You are required to keep a bound notebook. Include a table of contents on the first page and record all pertinent data/calculations/observations/etc for each experiment. It doesn’t have to be perfectly neat, but it must be legible. You will submit the notebook with your final report and a 20% of your total grade will depend on it. Lab Reports: Lab reports must be written INDIVIDUALLY, must be of journal quality, and must follow the JACS format. Online you can also find guidelines on http://www.rose-hulman.edu/~tilstra/ . Important Dates: Thursday, April 16th 2009 Journal-quality lab reports for the 1st lab due Thursday, April 30th 2009 Journal-quality lab report on the 2nd lab due Thursday, May 14th 2009 Journal-quality lab report on the 3rd lab due Thursday, May 28th 2009 Journal-quality lab report on the 4th lab due

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Before you start an experiment, ask the following questions 1. Do I understand the principle of the experiment? • If not, please go back and read about the experiment. 2. Do I know the experimental setup? • If not, go to the lab and find out, ask instructor, web/library search, read the instrument manual. 2. Do I have my lab notebook ready? • The simplest way to keep all the important data is to have a notebook. You are allowed to use the PC’s in the physical chemistry lab to do all the searches and keep good documentation. • Writing all the relevant information about how you are going to do the experiments will help you reduce the time it takes to finish the lab report. In the Lab: A Checklist • Do I have all the equipment necessary to setup the experiment? • How do I hook it up and start the experiment? • Safety first!!

o Use common sense. o With radiation or high voltage make doubly sure that you are following the appropriate procedure. If you are unsure please ask TA or Professor in charge. o Do not play with open electrical connections or liquid nitrogen.

• Prior to collection of data o Check if calibration run needs to be performed. o Check how the data will be saved. o Note the exact instrument model/serial numbers in your notebook. o Take a few minutes to look at the instrumentation manual. o Spend a few minutes to assess sample preparation/purity. o Determine the precision of the instrument.

• Data collection o Decide which variables are fixed and the uncertainties involved in their measurement. o See how minor perturbations of the experimental conditions affect your data. o Repeat…Repeat…REPEAT…to improve the accuracy/precision of the data. o Record everything in your notebook.

• After the experiment o Shut down the power and clean up the surroundings. o Write down brief notes in the logbook. o Notify instructor if there is any problem.

Analysis of Data • Identify the relationship between the independent/dependent variables. • Determine both precision/accuracy of measurements • Rejection of data: Students test. • Fitting the data

o Selection of equation. o Perform linear and/or nonlinear least squares analysis using proper weighting function.

• Compare your date to what is expected in the literature. • Summarize your conclusions and possible improvements.

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Experiment #2 Photolithography: Microprocessing Technology

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Experiment #4 Dills ABC parameters

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Experiment #5 Photolithography: Microprocessing Technology

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Photolithography procedure (Overview) Silicon wafers were coated with aluminum using microwave plasma chemical vapor deposition techniques. These wafers were then cleaned with IPA (isopropyl alcohol) and water, then air-dried. The aluminum-coated silicon was then spin coated using SPR 220-7 at 2000 rpm for 1 minute. The pre-exposure bake was conducted at 115 degree Celsius for ninety seconds. The photoresist was exposed using 11.5 mJ/cm2 for sixty seconds. The mask produced a given pattern on the wafer was selected by the TA. The soluble portion of the photoresist was removed using 0.02 M NaOH solution for 30 seconds. The wafer was then post-exposure baked for 90 seconds at 115 degrees Celsius. And then developed in 0.22 M NaOH solution at 40 degrees Celsius for 20 seconds to etch the image into the aluminum coating. The substrate was then washed with water to stop the development any farther, and the SEM was used to determine the angles of the substrate. Experiment #5: Photolithography Operating procedures

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