Performance enhancement of coating packaged ESC for semiconductor apparatus
View Patent ↗An advanced coating for electrostatic chuck used in plasma processing chamber is provided. The advanced coating is formed using plasma enhanced physical vapor deposition. The coating is generally of Y 2 O 3 /Al 2 O 3 , although other material combinations can be used. Also, a multi-layered coating can be formed, such that an intermediate coating layer can be formed using standard plasma spray, and a top coating can be formed using PEPVD. The entire ESC assembly can be “packaged” by the coating.
1. An electrostatic chuck (ESC) assembly for a plasma processing chamber, comprising:
a base plate;
a dielectric layer over the base plate;
an electrode over the dielectric layer; and,
an advanced coating consisting of a mixture of Y 2 O 3 /Al 2 O 3 or YF 3 /Al 2 O 3 and covering the ESC assembly except for rear surface of the base plate.
2. The ESC assembly of claim 1 , further comprising an undercoat layer provided under the advanced coating.
3. The ESC assembly of claim 2 , wherein the undercoat layer comprises at least one of Y 2 O 3 and Al 2 O 3 .
4. The ESC assembly of claim 2 , wherein the undercoat layer comprises at least one of Y 2 O 3 , YF 3 , YAG, ErO 2 , SiC, Si 3 N 4 , SiO 2 , ZrO 2 , Al 2 O 3 , AlN, and their combinations.
5. The ESC assembly of claim 1 , wherein the advanced coating comprises plasma enhanced physical vapor deposited Y 2 O 3 /Al 2 O 3 or YF 3 /Al 2 O 3 .
6. A method for fabricating an electrostatic chuck (ESC) assembly, comprising:
forming a dielectric layer over a base plate and an electrode over the dielectric layer to thereby form the ESC assembly;
inserting the ESC assembly into a vacuum chamber in an orientation such that it faces a source material positioned within the vacuum chamber;
evaporating or sputtering the source material inside the vacuum chamber;
injecting gas containing reactive species and non-reactive species into the vacuum chamber; and
forming plasma in front of the ESC assembly, such that ions of the reactive species and non-reactive species impinge upon the ESC assembly, to thereby form a coating over the ESC assembly, wherein the coating comprises atoms from the source materials and atoms from the reactive species to thereby form a mixture of Y 2 O 3 /Al 2 O 3 or YF 3 /Al 2 O 3 .
7. The method of claim 6 , wherein the source material comprises yttrium and aluminum.
8. The method of claim 7 , wherein the non-reactive species comprises argon and the reactive species comprises one of oxygen or fluorine.
9. A method of claim 6 , further comprising applying negative bias to the ESC assembly while maintaining the plasma inside the vacuum chamber.
10. The method of claim 9 , further comprising applying an intermediate coating to the ESC assembly prior to inserting the ESC assembly into the vacuum chamber.
11. The method of claim 10 , wherein the intermediate coating is formed by plasma spray.
12. The method of claim 11 , wherein applying the intermediate coating comprises applying plasma spray coatings of Y 2 O 3 , YF 3 , YAG, ErO 2 , SiC, Si 3 N 4 , SiO 2 , ZrO 2 , Al 2 O 3 , AlN, and their combinations.
13. The ESC assembly of claim 1 , wherein the advanced coating comprises a mixture of 40% Al2O3 and 60% Y2O3.
14. The method of claim 6 , wherein the coating comprises a mixture of 40% Al2O3 and 60% Y2O3.
15. The method of claim 6 , comprising utilizing two evaporation sources, one is for yttrium and another for aluminum to thereby evaporated the yttrium and aluminum separately.
16. The method of claim 15 , further comprising applying different power levels to the two evaporation sources.
17. The method of claim 6 , wherein evaporating the source material comprises directing electron beam onto the source material.