Crystal Orientation for Optimizing Quality and Yield throughout the Process Chain

We present here work on the orientation determination of bulk crystals for several different steps of wafer manufacturing (seeding, cutting, grinding, end control, etc.). X-ray diffraction is one of the standard analytical methods that are routinely utilized for both materials research and quality control. It is non-destructive and offers high precision and accuracy in lattice orientation measurements. The classic orientation method via rocking curves at different azimuthal angles is widely spread and yields results in 10-20 minutes for small off-orientations. For routine processes, this measurement time can adversely affect throughputs, and a faster solution is needed. Here we present a method two orders of magnitude faster, which determines an offcut magnitude in 10 seconds with precision of 0.003° 1σ. This is a strong improvement in methods compared to current industrial standards and enables control of each individual wafer at a throughput of up to 1 million wafers per automated wafer tool per year at single point per wafer. We will demonstrate the capabilities of this method with various examples and show how it can be used throughout the process chain, from seeding to wafering and ion implantation. The systems range from benchtops for quick check measurements to a fully automated robot-loaded wafer measurements via SECS/GEM protocol to automated boule glueing assemblies. Finding the orientation of a crystal on the diffractometer is only the first step. The sample then has to be transferred to the next processing step without losing the orientation. With our orientation transfer technology, we can enable, for example, accurate boule cutting and grinding. Combined with our stacking frame, it allows to attach up to twelve ingots of e.g. SiC to a saw beam for parallel cutting.