Supporting unit and substrate treating apparatus including the same

1. A fabrication method of a supporting unit supporting a substrate, the fabrication method comprising:

providing a supporting plate, the supporting plate made of a non-conductive material and configured to support the substrate;

providing a base plate, the base plate under the supporting plate and made of a material containing a conductive material, the providing a base plate including providing an upper base plate part and providing a lower base plate part to be bonded onto a bottom surface of the upper base plate part through a first brazing process;

forming a first metal film on a top surface of the base plate;

forming a second metal film on a bottom surface of the supporting plate;

providing a metal mesh between the first and second metal films; and

performing a second brazing process with regard to the first metal film, the second metal film, and the metal mesh to form a bonding intermediate that bonds the supporting plate with the base plate,

wherein a temperature of the first brazing process is higher than a temperature of the second brazing process.

2. The fabrication method of claim 1 , wherein the first metal film is made of a same material as the second metal film.

3. The fabrication method of claim 1 , wherein the bonding intermediate is a metal plate for buffering thermal expansion.

4. The fabrication method of claim 3 , wherein the metal plate contains aluminum (Al).

5. The fabrication method of claim 1 , further comprising:

forming a metal filler between the first metal film and the second metal film to enclose the metal mesh therein.

6. The fabrication method of claim 5 , wherein the metal filler contains aluminum (Al).

7. The fabrication method of claim 2 , wherein the first metal film and the second metal film contain aluminum (Al).

8. The fabrication method of claim 2 , further comprising:

forming a third metal film between the second metal film and the bottom surface of the supporting plate.

9. The fabrication method of claim 8 , wherein the third metal film contains titanium (Ti).

10. The fabrication method of claim 1 , wherein

the providing a base plate provides the base plate made of a conductive composite, which is a mixture of an additive and the conductive material, to minimize thermal stress due to a difference of thermal expansion rates between the base plate and the supporting plate,

the conductive material contains aluminum (Al), and

the additive contains one of silicon carbide (SiC), aluminum oxide (Al 2 O 3 ), silicon (Si), graphite, and glass fiber.