Selective deposition through formation of self-assembled monolayers
Methods of depositing a film selectively onto a first substrate surface relative to a second substrate surface are described. The methods include net chemisorption of a self-assembled monolayer on the second surface to prevent deposition of the film on the second surface.
1. A processing method comprising:
providing a substrate with a first surface and a second surface;
exposing the substrate to a SAM precursor to form a self-assembled monolayer on the second surface;
depositing a film on the first surface selectively over the second surface; and
removing the self-assembled monolayer from the second surface,
wherein the SAM precursor comprises a composition with a head group that adsorbs to the second surface and a tail group that associates through van der Waals interaction, and
wherein unreacted head groups of chemisorbed SAM precursors undergo ligand exchange with a treatment co-reactant and subsequently exchanged head groups of the SAM precursors react with each other via a condensation reaction to yield crosslinking between the chemisorbed SAM precursors.
2. The method of claim 1 , wherein the SAM precursor comprises more than one head group.
3. The method of claim 1 , wherein exposing the substrate to the SAM precursor further comprises exposing the substrate to a co-reactant to form the self-assembled monolayer.
4. The method of claim 3 , wherein the co-reactant is co-flowed into a process chamber with the SAM precursor.
5. The method of claim 3 , wherein the SAM precursor and the co-reactant are sequentially exposed to the substrate.
6. The method of claim 1 , wherein the substrate is exposed to the SAM precursor at a temperature T treatment and to the film deposition at a temperature T ALD greater than T treatment .
7. The method of claim 6 , wherein after cumulative exposure to the SAM precursor are complete but prior to deposition, the temperature of the substrate is elevated to T treatment <T≤T ALD for a time to allow net selective removal of SAM precursor from the first surface.
8. The method of claim 3 , wherein the SAM precursor and the co-reactant are exposed to the substrate a temperature in the range of about room temperature to about 250° C. and at a pressure up to about 760 Torr.
9. The method of claim 1 , wherein the first surface comprises H-terminated Si x Ge 1-x , a metal, or a metal oxide, and the second surface comprises hydroxyl-terminations on a Si-containing dielectric.
10. The method of claim 7 , wherein the SAM precursor comprises one or more chlorosilane and/or silylamine-based molecule with a linear, saturated hydrocarbon tail of 6-20 carbons and at least one —Cl or —NR 2 group, where each R is independently methyl or ethyl.
11. A processing method comprising:
providing a substrate with a first surface and a second surface;
exposing the substrate to a SAM precursor to form a self-assembled monolayer on the second surface, the SAM precursor comprising a composition with a head group that adsorbs to the second surface and a tail group that associates with other tail groups through van der Waals interaction;
depositing a film on the first surface selectively over the second surface; and
removing the self-assembled monolayer from the second surface.
12. The method of claim 11 , wherein exposing the substrate to the SAM precursor further comprises exposing the substrate to a co-reactant to form the self-assembled monolayer.
13. The method of claim 12 , wherein the co-reactant is co-flowed into a process chamber with the SAM precursor.
14. The method of claim 12 , wherein the SAM precursor and the co-reactant are sequentially exposed to the substrate.
15. The method of claim 12 , wherein the substrate is exposed to the SAM precursor at a temperature T treatment and to the film deposition at a temperature T ALD greater than T treatment , wherein after cumulative exposure to the SAM precursor but prior to deposition, the temperature of the substrate is elevated to T treatment <T≤T ALD for a time to allow net selective removal of the SAM precursor from the first surface.
16. A processing method comprising:
providing a substrate with a first surface and a second surface, the first surface comprises H-terminated Si x Ge 1-x , metal, or metal oxide, and the second surface comprises hydroxyl-terminations on a Si-based dielectric;
exposing the substrate to a SAM precursor and a co-reactant to form a self-assembled monolayer on the second surface, the SAM precursor comprising a composition with a head group that adsorbs to the second surface and a tail group that associates with other tail groups through van der Waals interaction, wherein forming the self-assembled monolayer occurs at a temperature T treatment , the SAM precursor is a chlorosilane and/or silylamine-based molecule with a linear, saturated hydrocarbon tail of 6-20 carbons and at least two —Cl and/or —NR 2 groups, where each R is independently methyl or ethyl;
elevating the temperature of the substrate to a temperature T greater than T treatment and holding the substrate at temperature T for a time;
elevating the temperature of the substrate to a temperature T ALD greater than or equal to T and depositing a film on the first surface selectively over the second surface by atomic layer deposition; and
removing the self-assembled monolayer from the second surface.