Metrology Bay

Rudalph Elipsometer
Location: 1.728
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*****Description: Elipsometer

*****Compatible Materials:

*****Incompatible Materials:

1. Turn up the screen intensity (the knob is on the right side of the monitor). If for some reason the computer has been turned off, then perform the following: Put the DOS startup disk into the left drive and turn the computer on. After the A> prompt appears, replace that disk with the DafIBM disk and type DAFIBM. The menu will appear on screen. See DafIBM procedures for setting up the program.
2. The standby mode for the ellipsometer's software (i.e. DAFIBM) is to measure thickness (Å) of SiO2 on silicon*. Please leave it in this mode when you are through.
3. Place the Rudolph 1238Å reference wafer on the stage, open the shutter to the laser (i.e. move the compensator up), and align the laser beam inside the rectangle on the wafer. Use the central microscope to check that the table is leveled. This is done by aligning the "moon" inside the cross hairs using the left and right tilt knobs under the stage. If these knobs are frozen, then loosen the front knob under the stage a little until they become free. Check the stage height alignment by checking that most of the laser light is entering the detector aperture, but do not adjust the height!
4. Press teh restart button located under the door. The ellipsometer will prompt** you to put the compensator in the up position and then press CONTinue. The next prompt requests that the compensator be put in the down position followed by pressing the CONTinue button. After the delta and psi values are displayed, check that the thickness displayed on the computer is 1238±1Å. If this is not the case, see the person in charge of the ellipsometer.
5. If the reference wafer is within tolerance, then the ellipsometer is ready to measure sample thicknesses. Remove the reference wafer and place it back in its container.
6. Place your wafer on the stage and check the stage tilt and height. Press CONTinue and wait for the thickness calculation to be displayed on the computer.
7. The calculation results are cyclic displaying a base thickness (0th order) and higher orders. For this reason, you must have a rough idea of your film's thickness to make sense of the output.
8. When you are finished, don't turn anything off, just turn down the intensity of the monitor using the knob on the right of the monitor.

*For measuring other materials, Double Layers, or unknown indices of refraction, see the DAFIBM procedures.
**The following two errors may appear: COMMUNICATION ERROR (see DAFIBM procedures and check interface cable to computer) or NULL NOT FOUND/BAD A0 (Try moving wafer slightly to make sure the reflected beam is entering detector, then push ). If the problem is persistent, see the person in charge of the ellipsometer.