US-12618154-B2 - Selective non-plasma deposition of mask protection material

Abstract

A method for selectively depositing a mask protection material using non-plasma treatments includes performing a non-plasma vapor treatment and performing a non-plasma halide treatment. During the non-plasma vapor treatment, a mask having openings exposing an underlying layer is treated with a non-plasma vapor to selectively deposit a first component of a mask protection material on the mask. During the non-plasma halide treatment, the mask and the underlying layer are treated with a non-plasma halide gas to selectively deposit a second component of the mask protection material on the mask. The non-plasma treatments are performed sequentially, but may be performed in either order. An optional pretreatment may be performed prior to the non-plasma treatments during which the mask is pretreated to form a reactive surface.

Inventors

• Yu-Hao Tsai
• Du Zhang
• Peter Biolsi

Assignees

• TOKYO ELECTRON LIMITED

Dates

Publication Date

20260505

Application Date

20231208

Claims (20)

1. 1 . A method comprising: performing a non-plasma vapor treatment comprising treating a mask having openings exposing an underlying layer with a non-plasma vapor to selectively deposit a first component of a mask protection material on the mask; and performing a non-plasma halide treatment comprising treating the mask and the underlying layer with a non-plasma halide gas to selectively deposit a second component of the mask protection material on the mask.
2. 2 . The method of claim 1 , further comprising: performing a pretreatment comprising pretreating the mask and the underlying layer to selectively form a reactive surface on the mask before performing both the non-plasma vapor treatment and the non-plasma halide treatment.
3. 3 . The method of claim 2 , wherein the pretreatment comprises treating the mask and the underlying layer with chlorine from a remote plasma.
4. 4 . The method of claim 2 , wherein the pretreatment comprises treating the mask and the underlying layer with a gas comprising hydrogen and oxygen.
5. 5 . The method of claim 2 , wherein the non-plasma vapor treatment comprises treating the reactive surface with the non-plasma vapor to form a vapor-treated surface on the mask, the vapor-treated surface comprising the first component, and wherein the non-plasma halide treatment comprises treating the vapor-treated surface with the non-plasma halide gas to form the mask protection material on the mask, the mask protection material comprising both the first component and the second component.
6. 6 . The method of claim 2 , wherein the non-plasma halide gas is a metal halide gas, wherein the non-plasma halide treatment comprises treating the reactive surface with the metal halide gas to form a halide-treated surface on the mask, the halide-treated surface comprising the second component, and wherein the non-plasma vapor treatment comprises treating the halide-treated surface with the non-plasma vapor to form the mask protection material on the mask, the mask protection material comprising both the first component and the second component.
7. 7 . The method of claim 2 , wherein the non-plasma vapor comprises ammonia vapor or water vapor.
8. 8 . The method of claim 1 , wherein the non-plasma halide gas is a metal halide gas.
9. 9 . The method of claim 1 , further comprising: continuing to deposit the mask protection material by concurrently applying the non-plasma vapor treatment and the non-plasma halide treatment.
10. 10 . The method of claim 1 , further comprising: continuing to deposit the mask protection material by alternating the non-plasma vapor treatment and the non-plasma halide treatment as part of a cycle.
11. 11 . The method of claim 1 , wherein both the non-plasma vapor treatment and the non-plasma halide treatment are performed in situ in a single deposition chamber.
12. 12 . A method comprising: performing a pretreatment comprising pretreating a carbon-based mask having openings exposing an underlying layer with a remote plasma species to selectively form a reactive surface on the carbon-based mask; performing a non-plasma vapor treatment comprising treating the reactive surface with a non-plasma nitrogen- or oxygen-containing vapor to deposit a first component and form a vapor-treated surface on the carbon-based mask; and performing a non-plasma halide treatment comprising treating the vapor-treated surface with a non-plasma halide gas to deposit a second component and form a mask protection material on the carbon-based mask, the mask protection material comprising both the first component and the second component.
13. 13 . The method of claim 12 , wherein the remote plasma species comprises chlorine.
14. 14 . The method of claim 12 , wherein the nitrogen- or oxygen-containing vapor is ammonia vapor or water vapor.
15. 15 . The method of claim 12 , wherein the non-plasma halide gas is boron chloride gas or titanium chloride gas.
16. 16 . The method of claim 12 , wherein the underlying layer is an ONON stack comprising alternating oxide layers and nitride layers or is an OPOP stack comprising alternating oxide layers and polysilicon layers.
17. 17 . A method comprising: performing a non-plasma metal halide treatment comprising treating a carbon-based mask having openings exposing an underlying layer with a non-plasma metal halide gas to deposit a first component and form a halide-treated surface on the carbon-based mask; and performing a non-plasma vapor treatment comprising treating the halide-treated surface with a non-plasma nitrogen- or oxygen-containing vapor to deposit a second component and form a mask protection material on the carbon-based mask, the mask protection material comprising both the first component and the second component.
18. 18 . The method of claim 17 , further comprising: performing a pretreatment comprising pretreating the carbon-based mask and the underlying layer with gas comprising at least one of water vapor, hydrogen peroxide (H 2 O 2 ), or hydrogen (H 2 ) and oxygen (O 2 ) to selectively form a reactive surface on the carbon-based mask before performing both the non-plasma vapor treatment and the non-plasma halide treatment.
19. 19 . The method of claim 17 , wherein the non-plasma metal halide gas is tungsten fluoride gas or titanium chloride gas.
20. 20 . The method of claim 17 , wherein the nitrogen- or oxygen-containing vapor is ammonia vapor or water vapor.

Description

TECHNICAL FIELD The present invention relates generally to protection of etch masks, and, in particular embodiments, to systems and methods for selectively depositing a mask protection material using non-plasma treatments. BACKGROUND Microelectronic device fabrication typically involves a series of manufacturing techniques that include formation, patterning, and removal of a number of layers of material on a substrate. Etch masks may be formed (e.g., deposited, grown, patterned) to protect regions of the substrate and allow for pattern transfer via etching. Wet or dry etching processes may be used, with plasma etching processes being an example of a dry etching process. Etching processes that etch dielectric materials are often used to create electrical (e.g., conductive) connections between and within layers. The overall yield of the fabrication process is affected by both the quality of the features formed during etching processes (the etch profile) and the uniformity of the process across the substrate. Mask loss (due to the mask material being etched away during the etching process) can degrade the etch profile and decrease uniformity, both of which lower the yield of acceptable devices during the fabrication. Mask loss may be especially pronounced when employing high bias power, such as during a high-aspect ratio (HAR) etch, which may be used for important fabrication steps like high-aspect ratio contact (HARC) etches. One conventional method of combatting mask loss is to use a different material as the bulk material of the mask, but this can be more complicated and/or more expensive. Another conventional method is to increase the mask thickness, but this can have negative impacts on the patterning capabilities of the mask itself as well as the attainable aspect ratio and critical dimension (CD) for the etched features. Carbon deposition during the etching process can also afford some mask protection, the carbon is deposited on all surfaces (i.e., non-selectively) including the material being etched and therefore can work against the etching process even as it may protect the mask to some extent. Therefore, improved deposition methods for mask protection materials that selectively deposit on the mask (and not on the etch target material) to improving selectivity may be desirable. SUMMARY In accordance with an embodiment of the invention, a method includes performing a non-plasma vapor treatment and performing a non-plasma halide treatment. During the non-plasma vapor treatment, a mask having openings exposing an underlying layer is treated with a non-plasma vapor to selectively deposit a first component of a mask protection material on the mask. During the non-plasma halide treatment, the mask and the underlying layer are treated with a non-plasma halide gas to selectively deposit a second component of the mask protection material on the mask. In accordance with another embodiment of the invention, a method includes performing a pretreatment, performing a non-plasma vapor treatment, and performing a non-plasma halide treatment. During the pretreatment, a carbon-based mask having openings exposing an underlying layer is treated with a remote plasma species to selectively form a reactive surface on the carbon-based mask. The reactive surface is treated with a non-plasma nitrogen- or oxygen-containing vapor during the non-plasma vapor treatment to deposit a first component and form a vapor-treated surface on the carbon-based mask. During the non-plasma halide treatment, the vapor-treated surface is treated with a non-plasma halide gas to deposit a second component and form a mask protection material on the carbon-based mask. The mask protection material includes both the first component and the second component. In accordance with still another embodiment of the invention, a method includes performing a non-plasma metal halide treatment and performing a non-plasma vapor treatment. During the non-plasma halide treatment, a carbon-based mask having openings exposing an underlying layer is treated with a non-plasma metal halide gas to deposit a first component and form a halide-treated surface on the carbon-based mask. During the non-plasma vapor treatment, the halide-treated surface is treated with a non-plasma nitrogen- or oxygen-containing vapor to deposit a second component and form a mask protection material on the carbon-based mask. The mask protection material includes both the first component and the second component. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: FIG. 1 illustrates an example method that includes performing a vapor treatment and a halide treatment on a patterned mask to selectively deposit a mask protection material where both treatments are non-plasma treatments in accordance with embodiments of