SEMICONDUCTOR DEVICE AND SEMICONDUCTOR SUBSTRATE, AND METHOD OF FABRICATING THE SAME
A substrate includes: a crystalline substrate including a primary surface and a crystal plane provided within the primary surface so as to have a surface orientation different from a surface orientation of the primary surface; a semiconductor layered structure grown over the crystalline substrate; and an active region provided at a portion in the semiconductor layer structure above the crystal plane.
1 . A substrate comprising:
a crystalline substrate including a primary surface so as to have a stepped portion;
a III-Nitride semiconductor layered structure grown over the crystalline substrate, wherein the semiconductor layered structure has a high defect region provided by concentrating lattice defects extending toward a tilted direction of the stepped portion and a low defect region in the vicinity of the high defect region; and
an active region provided at a portion of the low defect region.
2 . A substrate according to claim 1 , wherein the portion in the semiconductor layered structure at which the active region is provided contains fewer defects as compared to surrounding regions.
3 . A substrate according to claim 1 , wherein the crystal plane is a tilted surface which is tilted with respect to the primary surface of the crystalline substrate, and the active region is positioned above lattice defects which extend in a direction substantially perpendicular to the crystal plane.
4 . A substrate according to claim 1 , wherein a convex-and-concave structure is provided in the primary surface of the crystalline substrate, and the crystal plane is part of the convex-and-concave structure.
5 . A substrate according to claim 4 , wherein a convex portion included in the convex-and-concave structure has a forward mesa structure.
6 . A substrate according to claim 4 , wherein a convex portion included in the convex-and-concave structure has a cross section in the shape of a triangle pointing upward from the primary surface of the crystalline substrate.
7 . A substrate according to claim 4 , wherein the convex-and-concave structure has a periodic structure.
8 . A substrate according to claim 1 , wherein the active region is made of a III group nitride compound material, and serves as a light emitting region of a light emitting element.
9 . A substrate according to claim 1 , wherein the active region is made of a III group nitride compound material, and serves as a gate of a field effect transistor.
10 . A substrate according to claim 1 , wherein the active region is made of a III group nitride compound material, and serves as a base of a bipolar transistor.
11 . A substrate according to claim 1 , wherein the active region is made of a III group nitride compound material, and serves as a junction region of a diode.
12 . A substrate comprising:
a crystalline substrate;
a first III-Nitride semiconductor layer provided on the crystalline substrate;
a second III-Nitride semiconductor layer provided on the first semiconductor layer; and
an active region provided in the second semiconductor layer, wherein each of the crystalline substrate and the first semiconductor layer includes a primary surface and a crystal plane provided at least within the primary surface so as to have a stepped portion, and wherein the first semiconductor layer has a high defect region provided by concentrating lattice defects extending toward a tilted direction of the stepped portion.
13 . A substrate according to claim 12 , wherein the crystal plane of the first semiconductor layer is a tilted surface which is tilted with respect to the primary surface of the first semiconductor layer, and the active region is positioned above lattice defects extending in a direction substantially perpendicular to the crystal plane of the first semiconductor layer.
14 . A substrate according to claim 12 , wherein a convex-and concave structure is provided over the crystalline substrate, and the crystal plane of the crystalline substrate or that of the first semiconductor layer is part of the convex-and-concave structure.
15 . A substrate according to claim 14 , wherein a convex portion included in the convex-and-concave structure has a forward mesa structure.
16 . A substrate according to claim 14 , wherein a convex portion included in the convex-and-concave structure has a cross section in the shape of a triangle pointing upward from the crystalline structure.
17 . A substrate according to claim 14 , wherein the convex-and-concave structure has a periodic structure.
18 . A substrate according to claim 12 , wherein the crystal plane of the first semiconductor layer is positioned above the crystal plane of the crystalline substrate.
19 . A substrate according to claim 12 , wherein the active region is made of a III group nitride compound material, and serves as a light emitting region of a light emitting element.
20 . A substrate according to claim 12 , wherein the active region is made of a III group nitride compound material, and serves as a gate of a field effect transistor.
21 . A substrate according to claim 12 , wherein the active region is made of a III group nitride compound material, and serves as a base of a bipolar transistor.
22 . A substrate according to claim 12 , wherein the active region is made of a III group nitride compound material, and serves as a junction region of a diode.