News Article
Ferdinand-Braun researchers avoid SiC/GaN cracking with EpiCurve
Laytec, which makes in-situ metrology tools for LED, laser and thin-film production, has announced that researchers at Ferdinand-Braun-Institute in Berlin have successfully applied Laytec's EpiCurve in-situ metrology for optimising etching recipes in an ICP-RIE (inductive coupled plasma-reactive ion etching) tool (SI 500, Sentech).
With non-optimised plasma etching recipes, the SiC/GaN wafer (pasted to a glass or sapphire carrier) frequently cracks. This is because it suffers from a ±50µm wafer bow due to vertical temperature gradients and differences in the thermal expansion coefficients of carrier, substrate and GaN, according to Laytec.
Laytec reports that by using EpiCurve in-situ strain engineering, the Ferdinand-Braun team kept the wafer bow down to ±20µm (see Fig.1) and avoided wafer cracking.
