filename: REPORTS update

This is an update containing further details on your lab reports. You should still read Section A, p. Intro-1, that contains the old information on lab report format; most comments made there are still valid.

GENERAL COMMENTS:

As usual, where ever possible check your results based on "reasonableness" arguments. You should always find several other ways to check each measurement you have made, for instance by checking the expected process results against Ghandhi or the Lab Manual, by checking the process log books in lab, and by performing any calculations that are reasonable. REFERENCE ALL OUTSIDE SOURCES OF INFORMATION, AS WELL AS THE LOCATION OF YOUR RAW DATA IN YOUR LAB NOTEBOOK. As a general rule, the statement "as expected," when used in reference to the results of some measurement, is NOT acceptable, unless you state explicitly why it is expected.

MAKE COPIES OF THE TABLES INCLUDED HERE (pp. Up-6 through Up-8) FOR USE IN EACH LAB REPORT. I STRONGLY ADVISE YOU KEEP A COPY OF ALL YOUR COMPLETED TABLES AND DRAWINGS, IN ADDITION TO WHAT YOU TURN IN.

CRITIUQES

You are not only be responsible for writing lab reports, but also for critiquing other group's reports. The quality of your understanding of what you do and observe is influenced by how hard you work on the Lab Reports, and can be greatly enhanced by exposure to alternative views. This is not just a scheme to get you to grade the reports for me; I will read and grade the reports, as well as reading and grading your critiques. Except for Lab Report 0 you and your lab partner(s) will prepare the reports as a team, submitting one report per group. You will, however, do your critiques individually.

General comments about critiques:

You will receive a copy of another group's lab report. Read the report carefully; editorial comments should be made in the margins of the report. Try to flag things you do not understand, weak and/or unsupported arguments, or incorrect conclusions. Also flag good points, or conclusions you agree with but did not notice when you wrote your own report.

LAB REPORT "ZERO": DUE IN CLASS, Monday Sept. 4:

Critique of Lab Report 0, due in class, Monday, Sept. 21.

The remaining reports should be done in formal collaboration with your lab partner(s):

LAB REPORT I (one report per lab group; two copies required), due Monday, Oct. 19:

Critique of Lab Report I, due Monday, Nov. 2:

LAB REPORT II (one report per lab group; two copies required), due Monday, Nov. 16:

Critique of Lab Report II, due Friday., Dec. 4.

LAB REPORT III and TESTING (one report per lab group; one copy required) due Friday Dec. 4:

Questions for Lab Report 1

Discuss the following points in your lab reports. Please phrase your answers to questions 2 and 3 below in such a way as to re-state the question being answered. A short discussion is appropriate.

1. Give a brief overview of the process to date; an outline format would probably be most appropriate. You should clearly identify the location of each device in the Holberg Mask Set (pp. 38-47), along with the function of Masks 1, 2, 3 and 4 in terms of how they form the devices. You should include accurate, clearly labeled cross-sectional drawings of the MOSFET, diffused diode, and MOS capacitor with guard ring, at the following points in the processing: after step 4 (immediately before pre-dep); after step 6 (immediately before drive); and after step 10 (immediately before gate ox). Based on data gathered from your MPT chips you should be able to give some of the actual thicknesses of various layers in the devices.

2. Discuss the geometry correction factors necessary to interpret the four point probe measurements. Be careful to distinguish between the doped and undoped sides, and how this affects the dimensions you use for calculations of sheet resistance. Which measurements can be used to calculate a resistivity, and which can only be used to determine sheet R? Based on the measurements made so far, for what areas of the chip can you give an actual doping concentration, either background or diffused? Use this data to fill out the appropriate blocks in Tables II and III. Make sure you do not quote numerical results of precision greater than what you actually think is significant. You should give in the Tables an approximate value for the uncertainty. A short discussion of how you calculated each value (both the quantity of interest and its associated uncertainty) should be given.

3. Discuss the ellipsometric results. Again, make sure to consider in which cases your results are reasonable. The index of refraction calculated from your measurements is a good place to start. Reference from a book any materials properties you need to interpret the results. Fill out all the blocks in Table I that you have sufficient information to determine. Again you must determine how many significant figures you have actually measured to. You should give in the Tables an approximate value for the uncertainty. A short discussion of how you calculated each value (both the quantity of interest and its associated uncertainty) should be given.

4. Use the information gathered in the lab using the registration verniers and resolution bars on the masks to fill out Table IV. "Statistics" are important here, so indicate in footnotes how many measurements your numbers are based on.

Questions for Lab Report 2

1. Provide ACCURATE, CLEARLY labeled cross-sectional drawings of all the completed devices. You should have enough information to label your device cross sections with actual dimensions in both the vertical and horizontal directions. Based on the data you have obtained from the MPT chips, you should be able to fill out several more blocks in Tables I and II; as before, a short discussion of how you calculated each value (both the quantity of interest and its associated uncertainty) should be given.

2. Using information in Ghandhi, calculate the junction depths in your n- and p-type chips. Be very careful, and cross check any approximations you might use concerning diffusion constants, etc. Once you have calculated a diffusion profile you can use the Irwin curves to find the final sheet resistance of the diffused layers; compare this calculated value to your measured values, and discuss any differences. Show your junction grooving results, and compare them to your calculations.

3. Use the information gathered in the lab using the registration verniers and resolution bars on the masks to complete Table IV. "Statistics" are important here, so indicate in footnotes how many measurements your numbers are based on.

1. Draw diagrams for each device showing the relationship between the the device layout and the electrical connections to the device. Where necessary make sure that you consider connections through the backside of the chip. Indicate how the electrical test connections are made between the probe stations and the device-under-test (the DUT).

2. Device parameter extraction equations should be properly referenced, and great care used in determining what approximations have been used. The Lab Manual and OP's contain some of the necessary equations, but you will probably need to use some 339 equivalent text to get everything right.

PLEASE NOTE THE SIGN UP PROCEDURE FOR TESTING EQUIPMENT:

For each test station (CV Station; IV Station; Resistance Station) there will be a SIGN UP SHEET posted outside the lab. Please do NOT sign up for more than two time slots at a time.

Table 5: Lithography and Etch Results