Wafer carrier

1 . A wafer carrier with a bottom for connecting to a shaft, comprising:

a disc body having an accommodating groove for accommodating a wafer, wherein the disc body has a first surface and a second surface opposing each other; a groove bottom of the accommodating groove has the first surface; and

at least one heat insulator disposed on either the first surface or the second surface;

wherein when the wafer is accommodated in the accommodating groove, the at least one heat insulator is positioned between the wafer and the shaft, and

wherein the accommodating groove comprises an upper opening, a first groove section, and a second groove section; the first groove section is connected to the second groove section; a diameter of the first groove section is greater than a diameter of the second groove section; the first groove section has the upper opening and is for accommodating the wafer, and the second groove section has the first surface and is for accommodating the at least one heat insulator.

2 . The wafer carrier as claimed in claim 1 , wherein the diameter of the first groove section and the diameter of the second groove section gradually taper from the groove bottom of the accommodating groove towards the upper opening.

3 . The wafer carrier as claimed in claim 2 , wherein an angle between an inner wall of the first groove section and a horizontal reference plane parallel to the first surface, and an angle between an inner wall of the second groove section and the horizontal reference plane parallel to the first surface are both greater than or equal to 70 degrees and are both less than or equal to 80 degrees.

4 . The wafer carrier as claimed in claim 1 , wherein the at least one heat insulator comprises a first heat insulator disposed on the first surface and accommodated in the second groove section; a center of the first heat insulator has a center thickness along a shaft direction, and an outer peripheral edge of the first heat insulator has an edge thickness along the shaft direction, wherein the center thickness is greater than the edge thickness.

5 . The wafer carrier as claimed in claim 4 , wherein the second groove section has a height along the shaft direction; at a room temperature, the edge thickness of the first heat insulator is less than the height, and the center thickness of the first heat insulator is less than or equal to the height.

6 . The wafer carrier as claimed in claim 4 , wherein the second groove section has a height along the shaft direction; at a high temperature, the edge thickness of the first heat insulator is less than or equal to the height, and the center thickness of the first heat insulator is greater than the height.

7 . The wafer carrier as claimed in claim 6 , wherein the high temperature is greater than or equal to 900 degrees Celsius.

8 . The wafer carrier as claimed in claim 1 , wherein the at least one heat insulator comprises a second heat insulator; a bottom of the disc body has a recess for connecting to the shaft; the recess has the second surface, wherein the second heat insulator is disposed on the second surface.

9 . The wafer carrier as claimed in claim 1 , wherein a thermal conductivity of the at least one heat insulator is less than a thermal conductivity of the disc body.

10 . The wafer carrier as claimed in claim 9 , wherein a thermal conductivity of the wafer is between the thermal conductivity of the at least one heat insulator and the thermal conductivity of the disc body.

11 . The wafer carrier as claimed in claim 1 , wherein a projection of the wafer, a projection of the at least one heat insulator, and a projection of a contact surface of the shaft contacting with the wafer carrier that are projected onto a horizontal reference plane parallel to the first surface, respectively have a wafer projection area, a heat insulator projection area, and a shaft projection area; the wafer projection area is greater than the heat insulator projection area, and the heat insulator projection area is greater than the shaft projection area.