US-12618144-B2 - Surface treatment for selective deposition

Abstract

Methods of surface pretreatment during selective deposition are disclosed. One or more embodiment of the disclosure provides surface pretreatments which facilitate the removal of blocking layers. Some embodiments of the disclosure include a surface pretreatment comprising exposure of a substrate with a first surface and a second surface to modify the first surface, a blocking layer is deposited on the modified first surface, a film is selectively deposited on the second surface over the blocking layer, and the blocking layer is removed.

Inventors

• Carmen Leal Cervantes
• Yong Jin Kim
• Kevin Kashefi

Assignees

• APPLIED MATERIALS, INC.

Dates

Publication Date

20260505

Application Date

20220228

Claims (11)

1. 1 . A reverse selective deposition method comprising: exposing a substrate to a surface pretreatment comprising ammonia, the substrate including at least one feature extending from a top surface of the substrate to a bottom, the at least one feature having a width between a first sidewall and a second sidewall, the bottom comprising a first material with a first surface and the first sidewall and second sidewall comprising a second material with a second surface, wherein the pretreatment chemisorbs nitrogen atoms to at least a portion of the first surface and forms a modified first surface; exposing the substrate to a blocking compound comprising 5-decyne to selectively form a blocking layer on the modified first surface, wherein the nitrogen atoms are interposed between at least some molecules of the blocking layer and the first surface; selectively depositing a barrier layer on the second surface over the blocking layer, the barrier layer selected from the group consisting of tantalum nitride and titanium nitride; and removing the blocking layer from the first material, wherein the surface pretreatment does not contain plasma and facilitates the removal of the blocking layer from the first surface.
2. 2 . The method of claim 1 , wherein the first material comprises a conductive material and the second material comprises an insulating material.
3. 3 . The method of claim 2 , wherein the first material comprises one or more of copper, cobalt, tungsten, molybdenum or ruthenium.
4. 4 . The method of claim 2 , wherein the second material comprises one or more of silicon oxide, silicon nitride or a low-k dielectric.
5. 5 . The method of claim 1 , wherein the barrier layer is deposited by sequentially exposing the substrate surface to a metal precursor and a reactant.
6. 6 . The method of claim 5 , wherein the metal precursor comprises pentakis(dimethylamino)tantalum, the reactant comprises ammonia and the barrier layer comprises tantalum nitride.
7. 7 . The method of claim 1 , further comprising exposing the barrier layer and the blocking layer to a post-treatment before removing the blocking layer.
8. 8 . The method of claim 1 , wherein removing the blocking layer comprises exposing the substrate surface to a plasma formed from a plasma gas.
9. 9 . The method of claim 8 , wherein the plasma gas comprises hydrogen (H 2 ) and argon.
10. 10 . The method of claim 1 , further comprising depositing a second film on the barrier layer and the first material after removing the blocking layer.
11. 11 . The method of claim 1 , wherein the substrate is maintained at a temperature in a range of about 100° C. to about 300° C.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63/154,807, filed Feb. 28, 2021, the entire disclosure of which is hereby incorporated by reference herein. TECHNICAL FIELD Embodiments of the disclosure generally relate to surface treatments for selective deposition methods on non-metallic surfaces. More particularly, some embodiments of the disclosure are directed to methods of selective deposition on non-metallic surfaces using a surface treatment and blocking compounds comprising a SAM and/or an unsaturated hydrocarbon. The surface treatment facilitates removal of the blocking compound before later deposition. BACKGROUND Selective deposition processes are gaining a lot of momentum mostly because of the need for patterning applications for semiconductors. Traditionally, patterning in the microelectronics industry has been accomplished using various lithography and etch processes. However, since lithography is becoming exponentially complex and expensive the use of selective deposition to deposit features is becoming much more attractive. Another potential application for selective deposition is gap fill. In gap fill, the fill film is grown selectively from the bottom of a trench towards the top. Selective deposition could be used for other applications such as selective sidewall deposition where films are grown on the side of the fin. This would enable the deposition of a sidewall spacer without the need for complex patterning steps. In middle of the line (MOL) and back end of the line (BEOL) structures, barrier films are typically used between metal lines and dielectric layers to prevent diffusion and other adverse interactions between the dielectric layers and the metal lines. Yet barrier films are typically the largest contribution to via resistance due to their high resistivity. Past approaches have focused on reducing the thickness of barrier films or finding barrier films with lower resistivity to decrease via resistance. However, increased via resistance as a result of barrier films remains an issue, especially in smaller CD features when barrier films on sidewalls form an increasing percentage of the via volume. Another approach has been to block or decrease the thickness of the barrier film on the metal surface at the bottom of the via while the thickness on the dielectric surface at the sidewalls remains. Since the barrier properties of the barrier film directly relate to the thickness of the film between the metal and the dielectric, this approach allows for the barrier film to remain intact, but the reduced thickness on the metal surface improves via resistance. These processes are referred to as selective deposition processes. The current solution is to use of a self-assembled monolayer (SAM) to inhibit the nucleation and growth of the barrier film on the metal surface. To prevent deposition, a strong interaction between the SAM and the metal surface is preferred, but this interaction can be an obstacle to removal of the SAM for later deposition processes. Accordingly, there is a need for surface pretreatment methods which facilitate the removal of SAMs. SUMMARY One or more embodiments of the disclosure are directed to a selective deposition method comprising exposing a substrate comprising a first material with a first surface and a second material with a second surface to a surface pretreatment to modify the first surface and form a modified first surface. The substrate is exposed to a blocking compound to selectively form a blocking layer on the modified first surface. A first film is selectively deposited on the second surface over the blocking layer. The blocking layer is removed from the first material. The surface pretreatment facilitates the removal of the blocking layer from the first surface. BRIEF DESCRIPTION OF THE DRAWINGS So that some of the features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only some exemplary embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments. FIG. 1 illustrates a cross-sectional view of an exemplary substrate during processing according to one or more embodiment of the disclosure; FIG. 2 illustrates a cross-sectional view of an exemplary substrate during processing according to one or more embodiment of the disclosure; and FIG. 3 illustrates a schematic cross-sectional view of an exemplary substrate during selective deposition according to one or more embodiment of the disclosure; and FIG. 4. illustrates an exemplary cluster tool according to one or more embodiment of the disclosure. DETAILED DESCRIPTION Before describing several exemplary embodim