Sandia National Laboratories Installs kSA ICE Tool

DEXTER, Mich. - July 27, 2015 - PRLog -- Sandia National Laboratories recently installed a kSA ICE tool (http://www.k-space.com) on a modified EMCORE D-125 MOCVD reactor. The kSA Integrated Control for Epitaxy (kSA ICE) tool is a modular in situ metrology system capable of measuring multi-wafer real-time temperature, reflectivity, growth rate, film stress and substrate curvature during MOCVD processes.

This kSA ICE tool features the kSA patented reflectivity based pattern recognition software to keep track of individual wafers on this multi-wafer MOCVD system that does not have a locked carrier.  It also features reflectivity at a wavelength of 405 nm, in addition to reflectivity at longer wavelengths of 660 and 960 nm. The 405 nm reflectivity capability will allow Sandia to better study defect formation and surface roughness with the goals of minimizing such defects and improving epitaxy processes and device performance.

Figure 1 shows the simultaneous measurement of 405, 660, and 960 nm reflectance during GaN template deposition on sapphire measured at Sandia. The 405 nm reflectivity does not produce interference oscillations as only the first surface reflection is measured – the light that penetrates the GaN is absorbed because it is above the band gap of the material.  This technology can be used during well/barrier depositions to reveal differences in surface and interface quality that cannot be seen with longer wavelength light.  Run-to-run comparisons of 405 nm reflectivity during well/barrier growth can potentially help improve device yield and reproducibility.