Filmetrics Profilm3D Optical Profilometer SOP

Located in Main Lab (176)

TO: Victoria Pozzi (vpozzi3@gatech.edu) // MILL Wiki Article

[Computer Login] user: Mill_Conf // pw: filmetrics

Last updated June 27, 2025

Primary Use

The Profilm 3D Optical Profilometer uses white light interferometry to measure surface profiles and roughness. There are currently 10x, 20x, and 50x objectives that can resolve surface roughness down to 0.05μm. From each image, ProFilm’s analysis software can generate analyzable topological maps, which can also be exported as .STL files. Samples should be somewhat reflective (0.05%-100% reflectance), have a maximum vertical feature size of 100mm, thickness range (50nm-10mm). Otherwise, the profilometer will struggle to capture high quality images.

Operating Principle

Optical profilometers use the interference effects that occur when the light reflected from the sample is superimposed with the light reflected by a high-precision reference mirror to create a 3-d image.

Safety

Do not place your sample before the machine has fully booted up. Take care to not hit the lens with your sample, especially when using the 50x objective.

General Procedure

Startup & Loading Sample:

1. Log into the computer, the password is ‘filmetrics’
2. Turn on the Profilm3D and the Accurion stabilizer with the switches on the back right of both machines. Let the machine boot up, it will move up and down, this is normal.
3. After turning both machines on, start the Profilm by Filmetrics software.

1. The Profilm3D will begin moving the objectives up, all that is happening is the Profilm3D calibrating. Do not stop this as it is important for good imaging.

4. Make sure the objectives are far enough above the platform and load the sample. The maximum height a sample can be is 90 mm.

Controls (in Live Image Window)

Focus Tab (Just right of the image)

• The double arrows move the objectives up and down quickly for coarse focus, and the single arrows move it more slowly for fine focus.
• The step-up (top) button will move the head all the way to the top of its track.
• The red-emergency stop button stops the objective.

• Only really needed after using the step up button

• Height value is an arbitrary number. Can zero this value as a reference point and adjust quicker via this numerical tab.

X-Y Stage Tab (Center right of window)

• The double arrows move the stage quickly and the single arrows move it more slowly.
• The desired X-Y position can also be typed in the boxes at top as well
• The center button will move the stage to the X=0, Y=0 position.

Acquisition Tab (Far right of window)

• Important for making sure the scan will contain the proper area and features of interest.
• The objective lens indicates the current lens in use.
• The scan length and back scan determine the vertical scan range. Let’s say you start a scan at h=1mm, and you set a back scan of 0.01 mm and scan length of 0.02 mm. When you press start, the head will move down to 0.99 mm and it will start to scan up from there, to 1.01 mm.
• The measurement option allows the scan method to be switched between White Light Interferometry (WLI), Phase Shifting Interferometry (PSI), and a combination of both. For PSI, the sample must be much flatter before taking the scan than for WLI.  WLI allows for more scanning range but PSI is more accurate.
• The scan speed is indicative of how long the sensor waits for a response. For more accurate measurements and results, Normal speed is suggested. For quicker scans that are not as accurate, Fast speed is appropriate.

Image Intensity Tab (Bottom right of window)

• The image intensity is how bright the source is when taking a scan.
• For highly reflective samples it is suggested to decrease the intensity of the source so there are fewer invalid pixels.

Running a Scan

        Running a Manual Scan:

1. Begin by focusing the image on the 10x objective
2. While in focus on the 10x objective, move the sample stage to find the desired area of the sample for scanning. It is significantly easier to find the desired area at lower magnification.
3. Once over the desired area, switch to the 50x objective by manually rotating the turret to take a scan. After switching objectives, it may be necessary to adjust the focus a small amount.
4. Leveling the stage is important to have an accurate scan of the sample taken. The interference fringes are key for determining how flat the sample is before taking the scan. The wider spread out the interference fringes are, the flatter the sample is.

1. If the interference fringes are angled, so both tilt adjustment knobs to level the stage.
2. If the interference fringes are vertical, use the tilt knob on the right side of the stage
3. If the interference fringes are horizontal, use the tilt knob on the front of the stage.
4. If the interference fringes are angled use one knob until they are as spread out as possible and switch to the other knob.
5. It is a lot of guess and check work so just keep twisting one knob until the interference fringes get wider, if they aren’t getting wider try turning the knob the other direction.
6. The interference fringes indicate what height on the sample that is most in focus, this is important to keep in mind when setting up scan length and back scan.

Figure 1a-b: a) a highly tilted sample. b) the same sample but flat after adjustments were made.

5. Adjust the leveling and acquisition settings as desired. Be sure that you are focused on the highest point of your sample. This is where intimate knowledge of your sample topography is essential. The backscan and scan lengths should be in relation to the highest sample point.
6. Press the play button to take a scan

        Running an Auto-Scan

1. Remove interference fringes with the steps listed above
2. Underneath the stage height arrows, choose a top and bottom height for your scan
3. After doing so, the scan length will automatically adjust
4. Based on the magnitude of the scan length, choose an appropriate interferometry method (0-6 micrometers should be scanned with PSI, while WLI can be used for all else)
5. Set the backscan to 0
6. Press the play button to take a scan

Correcting a scan with operators

Figure 2: Screenshot highlighting the scan operators

Filling in the invalid pixels

• When the scan finishes, there is a chance there will be missing pixels due to the light not reflecting off the sample back to the microscope or not enough light reflecting back to the sensor. This causes gray pixels to appear in places around the image.
• To fix this go to the button that says, “Fill in invalids”.

Figure 3a-b: a) scan with invalid pixels shown in the blue circle and outliers shown in the red circle.

b) scan with the invalid pixels filled in.

Removing outliers

• When removing the outliers, it will ask at what slope to remove the outliers from. This means any slope at a greater angle than the slope chosen will be removed.
• The range for slopes is between 0° and 90°.
• Your sample may look much different after doing this; it is important to look at how the vertical scale changes. If there is drastic change in the scale, that likely means that there was an overall extrema that was removed by the operator.
• Make sure to check the box that says to fill in the invalids next to the chosen slope.

Leveling

• Two types: 3-point and facet.
• 3-point leveling is better when you know that there are three positions in the scan that are all supposed to be on the same level; you can place the nodes on those surfaces and level the sample.
• Facet leveling is better if you are unsure which surfaces are on the same level. In this technique, the software will subtract a plane from the scan that is parallel to the facets on the starting image.

Image properties

• Image settings is to the right of the operators. When you click on this you will see all the operators you added to the scan.
• You will also see a red X next to each operator to get rid of the effects of the operator on the scan. Note that when getting rid of an operator, any secondary operator below it will also be removed they were dependent on the effects of the primary operator.

Figure 4:  image properties.

Color scaling

• Using the color scaling feature the color can be changed from a rainbow to another set of colors to indicate different heights.
• This can be useful for exporting the sample and analyzing it in MATLAB. There is a gray scale feature allowing users to know that the higher regions are closer to white and the lower regions are closer to black.

General

• One important feature in this tab is that the vertical scale can be changed to be 1 to 1. This means that the 3D view will show what the surface of the sample actually looks like instead of an exaggerated view.

Analysis

Figure 5: Screenshot highlighting the analysis tools

Dimension

• The two types of dimensions that are available are circles and lines. When adding a dimension tool, it will appear on the top view image to the left of the 3D figure.
• To move the dimension tool around just click and drag the node to the desired location.
• Circles are good for measuring the size of circular features on the sample

• Only give the diameter as measurement

• Lines are good for measuring the distance between two features

• Gives the change in x, y, and z to see the difference in height between the two points

Figure 6: Screenshot demonstrating line and circle measurements.

Area Roughness

• Area roughness gives the measurements of the roughness in several styles such as, ASME B46.1 3D, EUR 15178N Amplitude, and ISO 25178 Height.
• The two measurement types are the entire image and restricted area.
• Entire image: Takes area roughness measurements across the entire area of the sample
• Restricted area: A yellow box will appear in the top view image to the left of the 3D image. Adjust the box to the size of the appropriate area to measure and position in the correct spot on the image. As the box is moved the roughness measurements will automatically update.

Line roughness

• Line roughness measures the roughness over a line on the sample and produces the ASME B46.1 2D and ISE 4287 Amplitude style of measurements.
• The line appears on the 3D image and the top view image on the left side of the screen. It can be adjusted by clicking and dragging the nodes one either end of the line.
• The software also gives a profile of the sample where the line goes over it.

Figure 7a-b: a) Screenshot of restricted area roughness measurement and accompanying statistics.

b): Screenshot of line roughness measurement and accompanying statistics

Volume

• The volume analysis tool is useful for finding the size of bumps or indentations (holes)
• To use this feature, add vertices to the top view image on the left side of the screen to create the boundaries of the area being investigated.
• With the vertices added the software will create a polygon and a best fit surface with the polygon.
• Across the best fit surface any volume of the sample that is above the surface will count as a bump and any empty volume below the best fit surface will count as a hole.

Figure 8: Screenshot of the volume measurement tool in use

Grain boundaries

• The grain boundaries tool is useful for finding grain boundaries or finding areas that are lower than the rest of the sample.
• Use the slider on the left side of the grain boundary tool to adjust the height at which the software looks for areas of different heights.
• When the software finds a grain, it will list in the table below the image on the right. Clicking on the gain in the table will highlight it in the image on the right.

Figure 9: Screenshot of the grain boundaries tool in use.

Saving and exporting

• To save a scan go to the blue arrow in the top left of the screen and click on the save button. Save the scan as a ‘Filmetrics Scan’ or a ‘Filmetrics complete scan’, doing so will save all measurements taken and can be uploaded to https://www.profilmonline.com/ to be viewed in a web browser.
• Using the export feature in the dropdown menu saves the 3D scan as an STL. This file type can be opened in any 3D viewer and 3D printed for project presentations.

Common issues/Debugging/Tips:

• When closing the profilometer, the stage height must NOT be set at its maximum value. This will disrupt the restartup of the profilometer due to faulty programming of the system.
• User Manual: https://www.phys.sinica.edu.tw/~bssf/docs/Profilm3D_Software_User_Manual.pdf