Heat-transfer structure and substrate processing apparatus
A heat-transfer structure which can keep a consumable component at a temperature of 225° C. or less during etching of a substrate. The heat-transfer structure is disposed in a chamber where plasma processing is performed on a wafer as the substrate under a reduced pressure. The heat-transfer structure is comprised of a focus ring having an exposed surface exposed to plasma, a susceptor and an electrostatic chuck that cool the consumable component, and a heat-transfer sheet interposed between the focus ring and the electrostatic chuck and made of a gel-like material. The ratio of hardness of the heat-transfer sheet expressed in Asker C to thermal conductivity of the heat-transfer sheet expressed in W/m·K is less than 20.
1. A heat-transfer structure disposed in a processing chamber in which plasma processing is performed on a substrate under a reduced pressure, the structure comprising: an electrostatic chuck
a consumable component including an exposed surface exposed to plasma; said consumable component includes an annular focus ring disposed to enclose an outer peripheral edge of the substrate;
a cooling component that cools said consumable component; and
a heat-transfer member interposed between said focus ring and said electrostatic chuck and made of a gel-like material,
wherein a ratio of a hardness of said heat-transfer member expressed in Asker C to a thermal conductivity of said heat-transfer member expressed in W/m·K is less than 20,
wherein a hardness of said heat-transfer member expressed in Asker C is 10 to 100, and
wherein a surface roughness of a contact surface of said focus ring is 6.3 μm or greater in Ra, the contact surface contacting said heat-transfer member.
2. The heat-transfer structure according to claim 1 , wherein
said cooling component includes a mounting stage on which the substrate and said focus ring are mounted,
said heat-transfer member is disposed outside the outer peripheral edge of the substrate, and
a thickness of said heat-transfer member is 0.3 mm to 0.7 mm.
3. A substrate processing apparatus, comprising:
a processing chamber in which plasma processing is performed on a substrate under a reduced pressure, an electrostatic chuck and
a heat-transfer structure disposed in the processing chamber, wherein
said heat-transfer structure includes a consumable component including an exposed surface exposed to plasma, said consumable component includes an annular focus ring disposed to enclose an outer peripheral edge of the substrate, a cooling component that cools the consumable component, and a heat-transfer member interposed between the focus ring and the electrostatic chuck and made of a gel-like material, and
a ratio of a hardness of the heat-transfer member expressed in Asker C to a thermal conductivity of the heat-transfer member expressed in W/m·K is less than 20,
wherein a hardness of the heat-transfer member expressed in Asker C is 10 to 100, and
wherein a surface roughness of a contact surface of said focus ring is 6.3 μm or greater in Ra, the contact surface contacting said heat-transfer member.
4. The substrate processing apparatus according to claim 3 , wherein
the cooling component includes a mounting stage on which the substrate and the focus ring are mounted,
the heat-transfer member is disposed outside the outer peripheral edge of the substrate, and
a thickness of the heat-transfer member is 0.3 mm to 0.7 mm.
5. The heat-transfer structure according to claim 1 , wherein the contact surface has not been polished.
6. The substrate processing apparatus according to claim 3 , wherein the contact surface has not been polished.
7. The heat-transfer structure according to claim 1 , wherein the thermal conductivity of said heat-transfer member expressed in W/m·K is 0.2 to 17.
8. The substrate processing apparatus according to claim 3 , wherein the thermal conductivity of said heat-transfer member expressed in W/m·K is 0.2 to 17.
9. The heat-transfer structure according to claim 1 , wherein the ratio is less than 20 such that a temperature of said consumable component is kept at less than a saturation temperature of 225° C. during the plasma processing.
10. The substrate processing apparatus according to claim 3 , wherein the ratio is less than 20 such that a temperature of said consumable component is kept at less than a saturation temperature of 225° C. during the plasma processing.