Raman, PL & AFM Measurements on Lithographically-Created Structures - Applications Note

Raman, PL & AFM measurements on lithographically-created structures Silicon (Si), being the second most common element in the earth’s crust, is the material most widely used for integrated circuits as well as solar cells. Modern integrated circuit devices work with structures down to 14 nm in size[1] and while the latest developments use a variety of different technologies, traditionally the structures in semiconductor devices are produced using lithography. In order to ensure the highest quality in the devices, the production steps need to minimize stress and stress induced artifacts. Other structures in which layers with different lattice constants are grown on top of each other require the strain for lattice matching. It has been shown [2,3] that Raman measurements can effectively probe the strain states of crystalline materials and provide an effective, nondestructive way of developing the most appropriate production processes. From solar cell research it is additionally known that stress and crystallinity in Si has a strong effect on the photoluminescence (PL) signal of the Si [4]. In this application note we report on structures in crystalline Si created by laser lithography which were in turn examined on the same instrument using confocal Raman imaging, confocal PL imaging and AFM.