Nanospec 010-180, nanospec
Picture and Location
Nanospec (white light area), this tool is located at FG4 on the Lab Map:
The nanospec appears in all three equipment groups (clean, semiclean, and gold).
What the Tool CAN do
- pieces to 8 inch wafers
- Measure thickness of up to two
transparent films on a substrate.
What the Tool CANNOT do
- Measure films thinner than 300 A.
- Measure refractive index.
- Measure more than 2 thin films.
How to Become a User
- Read all material on the SNF website concerning the Nanospec.
- Contact SNF training contact on the Equipment Summary page.
The NanoSpec/AFT Model 010-180 is a computerized film thickness measurement system for selected small areas. It includes a microspectrophotometer head, which can measure in the wavelength range of 390 - 800 nm, using a computer-controlled grating monochromator, photomultiplier tube detector, and amplifier. The amplifier output is converted to a digital signal by the computer, which then calculates film thickness with one of several algorithms. The front panel includes linear wavelength and photointensity (amplifier output) displays. The head is mounted onto a customized microscope with vertical reflected light illumination, using a regulated tungsten lamp, variable field diaphram, and 10X, 40X and 100X parafocal objectives, mounted in a five-position turret.
- When the power switch is turned ON, the terminal will display the question "IS WAVELENGTH 480?". Reply with "<YES/0>" or <NO/.>".
- The terminal will next display the available programs. Choose the desired program and continue.
- If you choose one of the 12 standard programs, the terminal will display the statement "ENTER OBJECTIVE LENS". You should then enter "1" (for 10X) or "2" (for 40X) or "3" (for 100X).
- Be sure the lens selected above is the one you use.
- The terminal will then ask you to focus on a reference wafer with the appropriate objective and to press "<MEAS> when ready. Do so.
- The terminal will then display the statement "ENTER SAMPLE ID". Enter the identification. This can have as many as 18 characters: all alphabetic characters, numbers, and punctuation are acceptable.
- From this point on, operation for any of the 12 standard programs . While you make measurements, as many as 60 numbered reading will be displayed on the CRT. It will display "MEASURING" at the bottom of the screen while it is obtaining data or computing results. You may accept or reject readings with the "<YES/0>" and "<NO/.>" keys. Rejected readings will not be used to compute any statistics.
- When the instrument is not measuring, you can display the statistics for the current program's data. Press "<DISPLAY STATISTICS>".
- When you wish to return to normal operation, press"<ENTER>".
Measuring a Sample
- If the display does not show available programs, press <CALIB>.
- Note: When <CALIB> is pressed and the 10X objective is focused on the bare Si calibration wafer a reading of 32 should appear on the upper left LED (photomultiplier). If not contact a technician for assistance.
- Select the program to be used (using the number pad on the right side of
the keyboard) and press <ENTER>.
1) Oxide on Si
2) Nitride on Si
3) Negative resist on Si
4) Poly on Oxide
5) Negative resist on Oxide
6) Nitride on Oxide
7) Thin Oxide on Si
8) Thin Nitride on Si
9) Polyimide on Si
10) Positive resist on Si
11) Positive resist on Oxide
12) Reflectivity Mod
- Select the objective to be used (position lens selected and enter the number of lens selected). "1" (for 10X) or "2" (for 40X) or "3" (for 100X) and press <ENTER>.
- You will be asked if you wish to measure a reference wafer (this is the bare Si wafer on the left side of the platform). If you wish to calibrate with the reference wafer press "<YES/0>"
- You will be instructed to focus on the reference wafers and push <MEAS>. To focus on a bare wafer (since there is no pattern to focus on) you should focus on the diaphram.
- For some programs (such as positive resist on oxide) you will be asked to enter the thickness of the bottom layer (oxide in this case). Enter the number and press <ENTER>.
- You will then be asked to "ENTER SAMPLE ID". Do so, or just push <ENTER> to continue.
- Then the terminal will prompt you for "REFRACTIVE INDEX?". If you wish to use the standard refractive index for that film, just push <ENTER>. If you wish to use a different refractive index, enter it using the numbered keys on the right of the keyboard and press <ENTER>.
- You will then be prompted to focus on your sample and push <MEAS>. Note: that the black dot in the center of view must be over the area to be measured (if the area to be measured is smaller that the dot, you must go to a higher power lens-- which means recalibrating to enter the new lens to be used).
- Your measurement will come up on the screen. If the thickness is below the measurement capability of the program you selected it will give you a "less than" number (ie less than 100 A if you are using program 1, or less than 20 A if you are using program 7). If the measurement is too high for the program you have selected you may get "OR" for out of range.
This measurement system is very dependent on the reflectivity of the sample. Sometimes if the sample is hazy (ie poly sometimes is) the reading may have a "*" by it. If it is really bad it may have a "?". This indicates that the readings may not be very reliable.