Method for manufacturing nitride semiconductor wafer or nitride semiconductor device; nitride semiconductor wafer or nitride semiconductor device made by the same; and laser irradiating apparatus used for the same
AssigneeNichia Corporation
InventorYoichi Nogami
Life of this patent
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Abstract
To remove the disparate substrate from nitride semiconductor layer grown over the disparate substrate, that is made of a material different from nitride semiconductor, by irradiating the disparate substrate with laser beam having a wavelength shorter than the band gap wavelength of the nitride semiconductor layer, while supplying an acidic or alkaline etching solution to the interface between the disparate substrate and the nitride semiconductor layer.
Claims19
A method for manufacturing a nitride semiconductor wafer comprising removing a disparate substrate from a nitride semiconductor layer that is grown over said disparate substrate which is different from said nitride semiconductor,
- wherein removal of said disparate substrate is carried out by irradiating said disparate substrate with a laser light of a wavelength shorter than the band gap wavelength of said nitride semiconductor layer while supplying an acidic or alkaline etching solution to the interface between said disparate substrate and said nitride semiconductor layer.
A method for manufacturing a nitride semiconductor device comprising:
- growing a plurality of nitride semiconductor layers for forming devices over a disparate substrate which is different from nitride semiconductor,
- attaching a support substrate on the top surface of said nitride semiconductor layer, and
- removing said disparate substrate from said nitride semiconductor layer, wherein
- removal of said disparate substrate is carried out by irradiating said disparate substrate with a laser light of a wavelength shorter than the band gap wavelength of said nitride semiconductor layer that is located nearest to said disparate substrate, while supplying an acidic or alkaline etching solution to the interface between said disparate substrate and said nitride semiconductor layer.
A laser irradiation apparatus for irradiating a semiconductor wafer with laser beam, comprising:
- a laser source;
- an etching bath that contains an acidic or alkaline etching solution;
- a holder for holding the wafer that is put into said etching bath;
- and
- an irradiation optical system for irradiating the entire surface of the wafer, that is held on said holder, with laser beam emitted from said laser source.
A nitride semiconductor wafer formed by growing a nitride semiconductor layer over a disparate substrate which is different from said nitride semiconductor and then removing said disparate substrate, wherein
- the surface left after removing said disparate substrate is a mirror surface having surface roughness of 10 nm or smaller.
A method for manufacturing a nitride semiconductor wafer, comprising:
- forming a stack of nitride semiconductor layers by stacking a first crystal layer made of a nitride semiconductor and a second crystal layer having at least a nitride semiconductor that has band gap energy higher than that of said first crystal layer;
- and
- removing said first crystal layer by irradiating said first crystal layer with light having a wavelength shorter than the band gap wavelength of said first crystal layer, while immersing said stack of nitride semiconductor layers in an acidic or alkaline etching solution.
Dependencies are inferred from the claim text.