OVERVIEW
As the name suggests, profilers are used to provide highly accurate representations of a sample’s profile. More specifically, they provide quantitative data and qualitative images on the surface topography of materials. There are two main types of profiler: optical (non-contact) profilers and stylus profilers. For more information on optical profilers, see our article on Interferometry. Stylus profilers operate by bringing a precision-formed stylus (usually made of diamond) into contact with a surface then moving the sample laterally underneath the stylus. As the sample runs laterally, the vertical displacement of the stylus is measured. This measurement represents the profile of the sample.
Contact profilers have been in use for over forty years. They offer an array of advantages to users engaged in primary research and basic quality assurance. The systems can quickly produce highly accurate results. Since it is a direct contact method, it is less sensitive to particulate on the sample than optical methods and it doesn’t require modeling. Modern profilers have been developed to offer great ease-of-use, making them accessible to even novice users.
TYPICAL APPLICATIONS
- Data Storage
- Materials Science
- Microelectromechanical Systems (MEMS)
- Optoelectronics
- Semiconductor Research
- Surface Science
- Solar Research
ENVIRONMENTAL CHALLENGES
Just as a record player will skip when someone stomps in the room, profilers will produce inaccurate measurements if they are affected by environmental vibration. Stylus profilers must maintain a uniform distance between the stylus and the stage, any relative motion will degrade the stylus’ ability to produce accurate measurements of the sample’s surface. Since the stylus is a very small piece which is cantilevered out from the main structure of the instrument, it is particularly sensitive to energy. As such, most stylus profilers require some type of vibration isolation systems. Less sensitive profilers can suffice with air-based isolation while higher-end systems require active vibration control to function at peak performance.
Stylus profilers also require some sort of enclosure around the stage to prevent buffeting by air currents and particulate contamination. For especially noisy environments, it is advisable to employ a soundproof hood or acoustic enclosure.