Practical application of devices using GaN substrates has been slow to progress. One of the big reasons is that the price of the GaN substrate is very expensive. To solve this issue, we propose a new GaN substrate slicing method using laser as a method that can contribute much more to the cost reduction of GaN substrate. With this technology, it is possible to reduce kerf loss to almost zero. Under the current slicing conditions, the damage depth after laser slicing is about 14um, and device epilayers could be grown on the sliced substrate by removing this thickness. In addition, this slicing does not require water or coolant and does not contaminate the workpiece. Therefore, laser slicing can also be used to thin the devices. By using laser slicing instead of backgrinding at the end of the device fabrication process, device layers can be thinned while leaving the substrate reusable.
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