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US 8,274,087 B2Granted
Nitride semiconductor substrate and manufacturing method of the same
AssigneeHitachi Cable, Ltd.
InventorShunsuke Yamamoto
Life of this patent
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AssigneeHitachi Cable, Ltd.
InventorShunsuke Yamamoto
Estimating the term…
To improve an adhesion to a substrate holder, and improve a device production yield by uniformizing a temperature distribution in a surface of a substrate and uniformizing characteristics such as a film thickness. When a concave warpage is set to be negative on a substrate front side, and a convex warpage is set to be positive on the substrate front side, then a line segment is drawn from one end of a substrate rear surface to the other end of the substrate rear surface, passing through a substrate center line, and a substrate is sliced by this line segment in a substrate thickness direction, a maximum value of shortest values of a distance from an arbitrary point on the drawn line segment to a rear side outline in a sliced surface, is defined as warpage H in a diameter direction, and when the warpage H in the diameter direction is obtained in a substrate peripheral direction, with its maximum value set to be Hmax, and its minimum value set to be Hmin, the warpage H in the diameter direction is defined to satisfy Hmax−Hmin≦30 μm.
A nitride semiconductor substrate, wherein when a concave warpage is set to be negative on a substrate front side, and a convex warpage is set to be positive on the substrate front side, which is a crystal growth surface side of the substrate, then a line segment is drawn from one end of a substrate rear surface to an opposing end of the substrate rear surface, which is a surface opposite side to the substrate front side, passing through a substrate center line, and the substrate is sliced by this line segment in a substrate thickness direction, a maximum value of shortest values of a distance from an arbitrary point on the line segment to a rear side outline in a sliced surface, is defined as warpage H in a diameter direction, and when the warpage H in the diameter direction is obtained in a substrate peripheral direction, with its maximum value set to be Hmax, and its minimum value set to be Hmin in the warpage H in the diameter direction in the surface of the substrate rear surface, the warpage H in the diameter direction is defined to satisfy Hmax−Hmin≦30 μm.
A nitride semiconductor substrate comprising:
Dependencies are inferred from the claim text.