Semiconductor device having aluminum nitride layer with void formed therein
A method of crystal growth is provided which can suppress development of dislocations and cracks and a warp in a substrate. The method of crystal growth of a group III nitride semiconductor has: a step of heating a silicon substrate; and a step of forming a depressed structure on the substrate surface by advance-feeding onto the heated silicon substrate a gas containing at least TMA (trimethylaluminum).
1. A semiconductor device comprising:
a silicon substrate;
an AlN layer grown on top of the silicon substrate; and
a nitride semiconductor layer formed on top of the AlN layer,
wherein a void is included inside the AlN layer,
the silicon substrate has a depressed structure on a top surface thereof, and the void in the AlN layer is located over the depressed structure.
2. The semiconductor device according to claim 1 , wherein
the void in the AlN layer is wedge-shaped.
3. The semiconductor device according to claim 1 , wherein
the nitride semiconductor layer includes a light-emitting layer having a quantum well structure.
4. The semiconductor device according to claim 3 , wherein
the light-emitting layer includes a well layer formed of AlGaN.
5. The semiconductor device according to claim 1 , wherein
a first electrode layer is formed on a top side of the AlN layer, and
a second electrode layer is formed on a bottom side of the AlN layer.
6. The semiconductor device according to claim 1 , wherein
a first electrode layer is formed on a top surface of a device structure after removal of the AlN layer, and
a second electrode layer is formed on a bottom surface of the device structure.