Ultrathin conformal coatings for electrostatic dissipation in semiconductor process tools
Disclosed in some embodiments is a chamber component (such as an end effector body) coated with an ultrathin electrically-dissipative material to provide a dissipative path from the coating to the ground. The coating may be deposited via a chemical precursor deposition to provide a uniform, conformal, and porosity free coating in a cost effective manner. In an embodiment wherein the chamber component comprises an end effector body, the end effector body may further comprise replaceable contact pads for supporting a substrate and the contact surface of the contact pads head may also be coated with an electrically-dissipative material.
1. An end effector for a robot arm, comprising:
an end effector body; and
a coating deposited on a surface of the end effector body, the coating comprising an electrically-dissipative material, wherein the electrically-dissipative material is to provide a dissipative path from the coating to ground, wherein the coating is uniform, conformal, and porosity free, wherein the coating has a thickness ranging from about 20 nm to about 500 nm, and wherein the coating has an electrical resistance ranging from about 1×10 5 ohm/sq to about 1×10 11 ohm/sq.
2. The end effector of claim 1 , wherein the electrical resistance of the coating remains unchanged after thermal cycling at a temperature ranging from about 300° C. to about 700° C.
3. The end effector of claim 1 , wherein the coating has a thickness ranging from about 20 nm to about 200 nm.
4. The end effector of claim 1 , wherein the end effector body comprises an electrically-conductive material, a ceramic, or quartz.
5. The end effector of claim 4 , wherein the end effector body comprises a conductive material that is a metal.
6. The end effector of claim 4 , wherein the end effector body comprises quartz and the coating is transparent.
7. The end effector of claim 1 , wherein the end effector body comprises a ceramic that is bulk alumina.
8. The end effector of claim 7 , wherein the electrically-dissipative material comprises alumina, titania, or a combination thereof.
9. The end effector of claim 8 , wherein the electrically-dissipative material comprises an alternating stack of alumina and titania.
10. The method of claim 9 , wherein a ratio of a thickness of each alumina layer to a thickness of each titania layer in the alternating stack of alumina and titania ranges from about 10:1 to about 1:1.
11. The end effector of claim 1 , wherein the coating is resistant to corrosive plasma.
12. The end effector of claim 1 , further comprising a replaceable contact pad disposed on the end effector body, the replaceable contact pad comprising a contact pad head having a contact surface configured to contact a substrate, and a shaft coupled to the contact pad head and received in an aperture formed in the body of the end effector and extending into a recess.
13. The end effector of claim 12 , wherein the coating is deposited on the surface of the end effector body and on the contact surface of the contact pad head.
14. A method comprising:
depositing a coating onto a surface of an end effector for a robot arm using an atomic layer deposition (ALD) process or a chemical vapor deposition (CVD) process, the coating comprising an electrically-dissipative material,
wherein the electrically-dissipative material is to provide a dissipative path from the coating to ground, wherein the coating is uniform, conformal, and porosity free, wherein the coating has a thickness ranging from about 20 nm to about 500 nm, and wherein the coating has an electrical resistance ranging from about 1×10 5 ohm/sq to about 1×10 11 ohm/sq.
15. The method of claim 14 , wherein depositing the coating using the ALD process comprises performing a deposition cycle comprising:
injecting a first material-containing precursor into a deposition chamber containing the end effector body to cause the first material-containing precursor to adsorb onto the surface of the end effector body to form a first half-reaction;
injecting a first reactant into the deposition chamber to form a second half reaction;
repeating the injecting the first material-containing precursor and the injecting the first reactant one or more times until a first target thickness of a first material-containing layer of the coating is achieved;
injecting a second material-containing precursor into the deposition chamber to cause the second material-containing precursor to adsorb onto the first material-containing layer to form a third half reaction;
injecting a second reactant into the deposition chamber to form a fourth half reaction; and
repeating the injecting the second material-containing precursor and the injecting the second reactant one or more times until a second target thickness of a second material-containing layer of the coating is achieved; and
repeating the deposition cycle one or more times until the thickness ranging from about 20 nm to about 500 nm is achieved.
16. The method of claim 15 , wherein the coating comprises an alternating stack of alumina and titania,
wherein the first material-containing precursor is an aluminum-containing precursor that comprises at least one of trimethylaluminum (TMA), diethylaluminum ethoxide, tris(ethylmethylamido)aluminum, aluminum sec-butoxide, aluminum tribromide, aluminum trichloride, triethylaluminum (TEA), triisobutylaluminum, trimethylaluminum, or tris(diethylamido)aluminum;
wherein the second material-containing precursor is a titanium-containing precursor that comprises at least one of tetrakis(dimethylamido)titanium;
wherein the first reactant and the second reactant comprises, independently, at least one of water, ozone, alcohol, and oxygen.
17. The method of claim 16 , wherein a ratio of a thickness of each alumina layer to a thickness of each titania layer in the alternating stack of alumina and titania ranges from about 10:1 to about 1:1.
18. A substrate processing system, comprising:
a chamber;
a robot disposed in the chamber; and
a robot arm connected to the robot, the robot arm comprising:
an end effector body;
a replaceable contact pad disposed on the end effector body, the replaceable contact pad comprising a contact pad head having a contact surface configured to contact a substrate, and a shaft coupled to the contact pad head and received in an aperture formed in the body of the end effector and extending into a recess; and
a coating deposited on a surface of the end effector body and on the contact surface of the contact pad head, the coating comprising an electrically-dissipative material, wherein the electrically-dissipative material is to provide a dissipative path from the coating to ground, and wherein the coating is uniform and conformal.
19. The substrate processing system of claim 18 , wherein the end effector body comprises an electrically-conductive material, a ceramic, or quartz, wherein the coating has an electrical-resistance ranging from about 1×10 5 ohm/sq to about 1×10 11 ohm/sq, wherein the coating has a thickness ranging from about 20 nm to about 500 nm, and wherein the coating is porosity free.
20. The substrate processing system of claim 18 , wherein the end effector body comprises bulk alumina, and wherein the electrically-dissipative material comprises an alternating stack of alumina and titania.