Surface profilometry is a contact measurement technique in which a diamond-tipped stylus is used to measure surface topography as it moves across the surface of a specimen.
The Facility operates a Sloan Dektak3ST Profilometer. This 2-D Profilometer has the capability to measure features ranging from a few nanometers to approximately 105 microns in height.
The Dektak profilometer uses a 2.5-micron (radius), conical stylus (90-degree cone angle). The stylus contact-force is adjustable from 10 to 400 microNewtons, allowing the instrument to measure a wide variety of materials without damaging them. The Dektak is controlled by a Windows PC. The software includes commonly used data processing and analysis capability. Data can be converted to ASCII (text) format and saved to a USB flash drive.
It is common to use a profilometer to measure film thickness and surface texture. Examples include thickness measurements made after spin coating or magnetron sputter deposition and height measurements that are used to calibrate the thickness monitor on a deposition system. Another important application is the measurement of crater depths for surface analysis methods that use depth profiling, such as Secondary Ion Mass Spectrometry (SIMS).
Materials such as semiconductors, polymers, metals, and ceramics are commonly measured using this instrument.
The Dektak can accommodate a wide variety of specimens. Most users who would like to measure film thickness will encounter less difficulty by using nominally flat specimens, such as glass slides, cover slips, and wafers (or pieces thereof), or pieces of metal, plastic, etc.
Curved, cylindrical, crumpled, or other non-flat specimens can be measured but you should be aware of how they will affect a measurement. Please consult Staff for assistance with unusual or challenging specimens.
More stringent specimen guidelines include:
- They must fit on the 165mm diameter stage.
- They must weigh under 1/2kg and be less than approximately 50mm tall overall.
- They must be stiff enough to support the force applied by the stylus during measurement. This means that foils and curled membranes or films will be very difficult to measure.
- Polymers and resist layers must be cured; sticky samples will not work.
- Powders are generally not permitted on the Dektak. Consult with Staff if you are considering this type of measurement.