Cleaning a component of a process chamber
Process deposits formed on a component of a process chamber are cleaned. In the cleaning method, gas holes in the component are mechanically pinned to clean the process deposits therein. A ceramic portion of the component is then exposed to an acidic solution, such as a solution of hydrofluoric acid and nitric acid. Mechanical pinning of the gas holes may be repeated after the acid cleaning step. The component is then plasma stabilized in a plasma zone by introducing a non-reactive gas into the plasma zone and forming a plasma of the non-reactive gas in the plasma zone. In one version, the component comprises an electrostatic chuck comprising a ceramic covering an electrode and having the gas holes therein.
1. A method of cleaning process deposits from a component of a process chamber, the component having a plurality of gas holes, the method comprising:
(a) mechanically pinning the gas holes of the component to clean the process deposits in the gas holes;
(b) exposing the component to an acidic solution; and
(c) plasma stabilizing the component by:
(1) placing the component into a plasma zone;
(2) introducing a gas into the plasma zone;
(3) forming a plasma of the gas in the plasma zone; and
(4) exhausting the gas from the plasma zone.
2. A method according to claim 1 comprising repeating (a) before and after (b).
3. A method according to claim 1 wherein the component comprises a ceramic covering an electrode, and wherein (b) comprises exposing the ceramic to an acidic solution comprising hydrofluoric acid and nitric acid.
4. A method according to claim 3 wherein the acidic solution comprises nitric acid and hydrofluoric acid in a ratio by weight of from about 3 to about 4.
5. A method according to claim 1 wherein (c)(2) comprises introducing a non-reactive gas into the plasma zone.
6. A method according to claim 5 wherein (c)(2) comprises introducing a non-reactive gas comprising argon or nitrogen into the plasma zone.
7. A method according to claim 1 comprising, before (c), testing the electrical resistance of the ceramic.
8. A method of cleaning process deposits from an electrostatic chuck, the electrostatic chuck having a plurality of gas holes and comprising a ceramic covering an electrode, and the method comprising:
(a) mechanically pinning the gas holes in the electrostatic chuck to clean the process deposits in the gas holes;
(b) exposing the ceramic to an acidic solution comprising hydrofluoric acid and nitric acid;
(c) repeating (a) after (b);
(d) testing the electrical resistance of the ceramic;
(e) plasma stabilizing the electrostatic chuck by:
(1) placing the electrostatic chuck into a plasma zone;
(2) introducing a non-reactive gas into the plasma zone;
(3) forming a plasma of the non-reactive gas in the plasma zone; and
(4) exhausting the non-reactive gas from the plasma zone.
9. A method according to claim 8 wherein in (b) the ratio of nitric acid to hydrofluoric acid by weight is from about 3 to about 4.
10. A method according to claim 8 wherein in (e)(2) the non-reactive gas comprises argon or nitrogen.
11. A method according to claim 8 wherein the electrostatic chuck comprises a metal base below the ceramic, wherein the metal base may be the electrode, and wherein (b) comprises exposing the ceramic of the chuck to the acidic solution substantially without exposing the metal base to the acidic solution.