Method of manufacture of group iii nitride semiconductor

Abstract

The invention provides a method for manufacturing a group III nitride semiconductor, which includes: preparing a group III nitride substrate having a first group III nitride layer and a second group III nitride layer laminated in this order from a back-surface side to a front-surface side, the first group III nitride layer being a layer having a transmittance of 60% or more for a predetermined wavelength of 400 nm to 700 nm, the second group III nitride layer being a layer provided on the first group III nitride layer and containing impurity oxygen in a concentration of 1*10<-20> / cm3 or more and having a transmittance of 0.1% or less for the predetermined wavelength; forming a device structure on the front-surface side of the group III nitride substrate; and forming an internal altered layer in the first group III nitride layer by multiphoton absorption using a laser beam applied from the first group III nitride layer side on the back-surface side of the group III nitride substrate with a focal point set in front of the second group III nitride layer, and dividing the group III nitride substrate at the internal altered layer serving as a boundary.

Description

technical field [0001] The present application relates to a method of manufacturing a Group III nitride semiconductor. Background technique [0002] LEDs for white lighting with blue wavelengths, blue light (Blu-Ray) reading, laser diodes with ultraviolet to blue wavelengths used as light sources for welding processes, frequency conversion in power systems, and motor control A power device uses a single crystal Group III nitride semiconductor substrate (a GaN substrate is exemplified below) as a material. [0003] The GaN substrate generally has a thickness of 300 to 700 μm and a circular shape with a diameter of 50 to 150 mm. Generally, a GaN substrate has a transmittance of 60% or more and is transparent to visible light. [0004] On the other hand, an example of a method of fabricating a device structure from a GaN substrate is shown in Figure 5-1 to Figure 5-6 . Figure 5-1 to Figure 5-6 It is a schematic cross-sectional view showing each step in a manufacturing metho...

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Problems solved by technology

[0013] SiC substrates are also expensive substrates like GaN substrates

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