Method for fabrication of semiconductor light-emitting device and the device fabricated by the method
A method for producing a semiconductor light-emitting device includes stacking at least a first conductive type semiconductor layer ( 2 ), an active layer ( 3 ) and a second conductive type semiconductor layer ( 4 ) on a substrate ( 1 ) to form a wafer, then forming on a side of growth surfaces of the semiconductor layers first trenches ( 40 ) exposing the first conductive type semiconductor layer, further forming second trenches ( 50 ) reaching the substrate from above the first trenches by using a laser beam, subsequently forming third trenches ( 60 ) from the substrate at the positions corresponding to the second trenches, and finally cutting the wafer into chips. The produced semiconductor chips provide an enhanced efficiency of extracting emitted light even when the end faces thereof are smooth surfaces and they allow the semiconductor layer to be cut without distorting the end faces of the chips.
1. A method for the fabrication of a semiconductor light-emitting device, comprising the steps of:
stacking at least a first conductive type semiconductor layer, an active layer and a second conductive type semiconductor layer on a substrate to form a wafer;
forming on a side of growth surfaces of the semiconductor layers first trenches so as to expose a lateral surface of the first conductive type semiconductor layer at the end of the first trench forming step;
forming second trenches reaching the substrate from above the first trenches by the use of a laser beam so that at least a part of the lateral surface of the first conductive type semiconductor layer remains exposed at the end of the second trench forming step;
forming third trenches from the substrate at positions corresponding to the second trenches by the use of a laser beam;
using a dicing blade to correct a shape of the third trenches; and
dividing the wafer into chips.
2. A method according to claim 1 , wherein the third trenches have a greater width than the second trenches.
3. A method according to claim 1 , wherein the third trenches have a greater width than the first trenches.
4. A method according to claim 1 , wherein the third trenches are formed by radiating a laser beam two times or more.
5. A method according to claim 1 , wherein the substrate is lapped, ground or polished till a thickness thereof reaches 100 μm or less inclusive of an epitaxial layer prior to the formation of the third trenches.
6. A method according to claim 1 , wherein the first conductive type semiconductor layer is an n-type semiconductor layer and the second conductive type semiconductor layer is a p-type semiconductor layer.
7. A method according to claim 1 , wherein the substrate is a sapphire substrate.
8. A method according to claim 1 , wherein the semiconductor light-emitting device is a nitride-based semiconductor light-emitting device.
9. A method according to claim 1 , wherein the semiconductor light-emitting device is a gallium nitride-based semiconductor light-emitting device.
10. A semiconductor light-emitting device produced by using the method for the fabrication of the semiconductor light-emitting device according to claim 1 .