Sensofar and Linkam Develop Technique For Characterising The Temperature-Induced Topographical Evolution of Nanoscale Materials
Product News Jun 02, 2021
Stacked 4D view of the topographies extracted from two samples corresponding to different chip designs from silicon wafers (a) sample A and (b) sample B for visual comparison of the experimented bow change when samples go from 30ºC to 380ºC.
Sensofar has developed a new technique for characterising the evolution of a sample’s surface topography with temperature using the S neox 3D optical profiler and Linnik interferometer coupled with Linkam’s LTS420 temperature-controlled chamber. The technique has been used to successfully map the changes in roughness and waviness of silicon wafers at temperatures up to 380°C.
Optical profilometry is a rapid, non-destructive, and non-contact surface metrology technique, which is used to establish the surface morphology, step heights and surface roughness of materials. It has a wide range of applications across many fields of research, including analysing the surface texture of paints and coatings, analysing micro-cracks and scratches and creating wear profiles for structured materials including micro-electronics, and characterisation of textured or embossed nanometre-scale semiconducting components, such as silicon wafers.
Historically, it has been difficult to conduct temperature-controlled optical profilometry experiments due to imaging issues caused by changes in spherical aberration with temperature of both the front lens of the objective and the quartz window of the LTS420 stage.
By using Sensofar’s new Linnik interferometer lens system with the S neox 3D optical profiler, in combination with Linkam’s LTS420 precision temperature control chamber, spherical aberration issues are resolved, enabling the accurate measurement of 3D topographic profiles of nanoscale materials at a wide range of temperatures.
David Páez, Sensofar Sales Support Specialist, commented: “In a recent experiment using the new technique, we were able to observe the changes in topography of silicon wafers as they evolve with temperature from 20°C up to 380°C. This is critical information for silicon wafer producers and users, so that they can optimise their process, improve semiconductor properties and wafer durability. The Linkam LTS420 chamber and T96 temperature controller are key components in our experimental set-up and enable us to ramp and control the temperature between -195° and 420°C to a precision of 0.01°C.”
Robert Gurney, Linkam’s Application Specialist, added: “We have provided precise temperature and environmental control to a wide range of techniques, from microscopy to X-ray analysis, for decades. This collaboration highlights the important role of temperature control in contributing to innovative approaches to material characterisation. We are extremely pleased to be able to offer a solution for temperature-controlled profilometry thanks to Sensofar’s Linnik interferometer, and we look forward to seeing how this new technique helps researchers across many scientific fields to advance their research and knowledge.”