Methods and apparatus for cryogenic gas stream assisted SAM-based selective deposition
Methods and apparatus for removing deposits in self-assembled monolayer (SAM) based selective deposition process schemes using cryogenic gas streams are described. Some methods include removing deposits in self-assembled monolayer (SAM) based selective depositions by exposing the substrate to cryogenic aerosols to remove undesired deposition on SAM protected surfaces. Processing chambers for cryogenic gas assisted selective deposition are also described.
1. A method comprising:
exposing a substrate comprising a first surface and a second surface to a self-assembled monolayer (SAM) precursor to selectively form a SAM layer on the first surface over the second surface, the SAM layer containing defects that expose portions of the first surface;
depositing a film by atomic layer deposition (ALD) on the second surface and exposed portions of the first surface, the film having a first average thickness on the first surface and a second average thickness on the second surface, the first average thickness being less than the second average thickness; and
exposing the substrate to a cryogenic gas stream comprising an aerosol having particles of cryogenic gas clusters to remove an amount of the film from the first surface, the particles having a root mean square velocity greater than or equal to about Mach 2.
2. The method of claim 1 , wherein the first surface is on a dielectric material and the second surface is on a conductive material.
3. The method of claim 2 , wherein the dielectric material comprises one or more of silicon oxide, silicon nitride or silicon carbide.
4. The method of claim 2 , wherein the conductive material comprises one or more of ruthenium, copper or cobalt.
5. The method of claim 1 , wherein the film comprises a metal oxide.
6. The method of claim 1 , wherein the cryogenic gas stream comprises one or more of CO 2 , N 2 , Ar or Ne.
7. The method of claim 1 , wherein the root mean square velocity is in a range of about 800 m/s to about 1750 m/s.
8. The method of claim 1 , wherein the SAM layer is substantially unaffected by the cryogenic gas stream.
9. The method of claim 1 , wherein the cryogenic gas stream removes substantially all of the film from the first surface.
10. The method of claim 1 , further comprising repeating depositing the film and exposing the substrate to the cryogenic gas stream to form a film with a predetermined thickness on the second surface.
11. A method comprising:
exposing a substrate on a susceptor to a flow of a SAM precursor through a gas distribution assembly positioned so that a front face of the gas distribution assembly faces a top surface of the susceptor, the front face of the gas distribution assembly and the top surface of the susceptor defining a process volume, the substrate comprising a first surface and a second surface, the SAM precursor selectively forming a SAM layer on the first surface over the second surface, the SAM layer containing defects that expose portions of the first surface;
depositing a film by atomic layer deposition (ALD) on the second surface and exposed portions of the first surface by providing a flow of one or more deposition gases through the gas distribution assembly, the film having a first average thickness on the first surface and a second average thickness on the second surface, the first average thickness being less than the second average thickness; and
removing an amount of the film from the exposed portions of the first surface by providing a cryogenic gas stream with a spray pattern and a spray area from a high-speed cryogenic gas nozzle into the process volume, the cryogenic gas stream having a root mean square velocity greater than or equal to about Mach 2.