This semiautomatic profilometer can be used for single and multiple scans. It provides data on a film thickness, or on a surface roughness and also allows the generation of 3D images. By measuring the curvature of a sample before and after deposition of a thin film, the residual stress of the thin film can be determined from Stoner’s equation.
Rev 01: Alina Kulpa
Rev 02: Mario Beaudoin, April 2017
You should normally find the Dektak powered ON and with a silicon wafer sample on the chuck. The sample is kept there to protect the stylus in case of a non-controlled scan. If the unit is not powered, push the white button on the external power box.
- Make sure that your sample is clean on both sides without any sticky stuff on it, and that it is flat on the back
- On the computer, double click on the VISION 64 program icon (See Figure on left)
- The system will prompt you before zeroing the stage X-Y and Theta (rotation) positions. Click OK at both prompts.
- Wait until the system reaches the “home” position (tower should be up and stylus over the middle of the chuck)
- When the system has finished its initialization, you will see the camera image of the stylus and the front panel of the control program (See bottom image on Figure at left).
- Click Unload Sample; The stage will move forward.
- load your sample, place it approximately where a scan should be done (keep in mind that the scan is along a line going front to back)
- Click Load Sample; the stage will move under the stylus.
- Click the Tower Down button; this brings the stylus down.
- Once the tower is down, you should see the surface of your sample; if you are lucky and have large features, it would look like the top image on the Figure to the right.
- Click, drag and hold the red dot in the top right hand side of the control window to move your sample to the desired position.
- Click, drag and hold the red dot in the bottom right hand side of the control window to rotate your sample to the desired position.
- In the measurement setup panel, choose the height range, length of scan and duration of scan. Note the fire/pencil icon next to the length box; this can be used, along with the red dots to manually choose start and end positions of the scan.
- Click on the green Measurement button to begin the scan; you will see the stylus move over the sample while the trace is reported on a graph (see middle image on figure to the right).
- If the sample is tilted too much, it may be necessary to manually level the stage. This is done by turning the leveling knob in front of the stage (figure on top of page).
- If the trace clips at either top or bottom of the trace graph during measurement, increase the measurement range.
- When the measurement is complete, you will see a screen similar to the bottom image on the figure at the right. You can move and enlarge the R (reference) and M (measurement) cursors to electronically level the trace and to measure the height difference between the 2 cursors (in this example, the feature is 27.83 μm.
- If you wish to use 3D mapping, you also need to choose Map Scan from the topmost subwindow; this feature is trickier and you should discuss with the cleanroom personnel before attempting to use 3D mapping.
- Repeat steps 6 – 18 to unload/load and measure new samples.
- Several save and export features are available from the top left corner icon.
When your measurements are complete:
- Click on the Tower Home button
- Load the silicon “protection” sample back on the stage
- Exit the program without storing your scanning parameters in it
- Make sure the front door of the Dektak is closed.
For more information, the full users manual is on a DVD loaded in the Dektak computer.
Superuser: Mario Beaudoin