Atomic layer deposition of aluminum oxide films for semiconductor devices using an aluminum alkoxide oxidizer
Patent Information
- Authority / Receiving Office
- TW · TW
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-03-23
- Publication Date
- 2023-01-01
Smart Images
Figure TWG2TA000889617_001 
Figure TWG2TA000889617_002 
Figure TWG2TA000889617_003
Abstract
Description
[Technical Field]
[0001] This application claims priority and rights on the filing date of U.S. Provisional Patent Application No. 63 / 166,846, filed on March 26, 2021, the entire contents of which are incorporated herein by reference.
[0002] This invention relates to semiconductor processing and semiconductor devices, and more particularly to a method for depositing aluminum oxide (Al2O3) films using an anhydrous oxidant. [Previous Technology]
[0003] As device sizes shrink, the complexity of semiconductor device manufacturing is increasing. The cost of producing semiconductor devices is also rising, necessitating cost-effective solutions and innovations. Manufacturing critical dimensions (CDs) or resolutions of patterned features is becoming increasingly challenging when producing smaller transistors. Selective deposition of thin films is a key patterning step in highly scalable technology nodes.
[0004] Water (H2O), O2 plasma or free radicals, and ozone (O3) are commonly used as oxidants in ALDs of oxide films. However, these gases are strong oxidants and can cause undesirable oxidation of the substrate material, becoming a significant problem in the scaling up of advanced devices. One example involves the deposition of high dielectric constant (high k-value) metal oxide films, in which strong oxidants oxidize the underlying Si substrate and form a thick low k-value interface SiO2 layer. New deposition methods are needed to provide selective film deposition on different material surfaces while avoiding surface oxidation. [Summary of the Invention]
[0005] A method for atomic layer deposition of an aluminum oxide film using an anhydrous oxidant. According to one embodiment, the method includes providing a substrate comprising a dielectric layer and a metal layer or a semiconductor layer, and selectively depositing an aluminum oxide film on the surface of the dielectric layer relative to the surface of the metal layer or the surface of the semiconductor layer by a) exposing the substrate to an aluminum alkane gas, an aluminum halide gas, or an aluminum hydride gas, and b) exposing the substrate to an aluminum alkane gas, wherein the aluminum alkane gas is the primary source of oxygen in the aluminum oxide film.
[0006] According to another embodiment, the method includes providing a substrate comprising a dielectric layer and a metal layer or a semiconductor layer, and selectively depositing an aluminum oxide film on the surface of the metal layer or the surface of the semiconductor layer relative to the surface of the dielectric layer by a) exposing the substrate to a molecularly-containing reactive gas that forms a self-assembled monolayer (SAM) on the surface of the dielectric layer, b) exposing the substrate to an alkane alumina gas, an aluminum halide gas, or an aluminum hydride gas, and c) exposing the substrate to an alkane alumina gas, wherein the alkane alumina gas is the primary source of oxygen in the aluminum oxide film.
[0007] According to another embodiment, the method includes providing a substrate including raised features and a bottom region, the raised features having sidewalls and a top, the bottom region being located between the raised features, and selectively depositing an aluminum oxide film on the top of the raised features and the upper part of the sidewalls relative to the bottom region, by a) exposing the substrate to an aluminum alkane gas, an aluminum halide gas, or an aluminum hydride gas to form a conformal adsorption layer on the raised features, and b) exposing the substrate to an aluminum alkane gas, wherein the aluminum alkane gas is the primary source of oxygen in the aluminum oxide film.
[0008] According to another embodiment, the method includes providing a substrate including a raised feature portion and a bottom region, the raised feature portion having sidewalls and a top, the bottom region being located between the raised feature portions, and selectively depositing an aluminum oxide film on the sidewalls and the bottom region relative to the top, by a) exposing the substrate to an alkane alumina gas, an aluminum halide gas, or an aluminum hydride gas to form a conformal adsorption layer on the raised feature portion, b) deactivating or removing the adsorption layer on the top, and c) exposing the substrate to an alkane alumina gas, wherein the alkane alumina gas is the primary source of oxygen in the aluminum oxide film.
Implementation Method
[0015] The method described herein is used for vapor phase atomic layer deposition (ALD) of aluminum oxide films on patterned substrates, which uses anhydrous oxidants including alkane aluminum oxide.
[0016] Figures 1A-1C are schematic cross-sectional views illustrating a process for depositing an aluminum oxide film on a substrate according to an embodiment of the present invention. In Figure 1A, the substrate 1 includes a dielectric layer 100 having a surface 100A, a metal or semiconductor layer 104 having a surface 104A, and an optional diffusion barrier layer 102 having a surface 102A. The dielectric layer 100 may include, for example, SiO2 or a metal-containing dielectric layer. In other examples, the dielectric layer 100 may include a low-k material, such as SiCOH. In one example, the metal-containing dielectric layer may include a metal oxide, a metal nitride, or a metal oxynitride. In some examples, the metal or semiconductor layer 104 includes Cu, Al, Ta, Ti, W, Ru, Co, Ni, Mo, Si, Ge, or SiGe. Although not shown in Figure 1A, the surface 104A of the metal or semiconductor layer 104 may be recessed a few nanometers below the surface 100A of the dielectric layer 100.
[0017] The method includes selectively depositing an aluminum oxide film 106 on the surface 100A of the dielectric layer 100 relative to the surface 104A of the metal or semiconductor layer 104 by ALD. ALD includes exposing the substrate to an aluminum alkane gas, an aluminum halide gas, or an aluminum hydride gas to form an aluminum-containing adsorption layer on the surface 100A, and subsequently exposing the substrate to an aluminum alkane gas, which reacts with the adsorption layer to form the aluminum oxide film 106. The aluminum alkane gas is the primary source of oxygen in the deposited aluminum oxide film 106, and the reaction involves the coordination of oxygen atoms from the alkoxy groups of the aluminum alkane to the aluminum metal center of the adsorption layer.
[0018] The selective deposition of the aluminum oxide film 106 on the surface 100A of the dielectric layer 100, relative to the surface 104A of the metal or semiconductor layer 104, is achieved by a longer deposition incubation time on the surface 104A of the metal or semiconductor layer 104, wherein the deposition of the aluminum oxide film is not desired on the surface 104A of the metal or semiconductor layer 104 compared to the surface 100A of the dielectric layer 100 where the aluminum oxide film is desired to be deposited. The sequence of ALD processes and alternating gas exposures can be repeated at least once while maintaining the selectivity of deposition to increase the thickness of the aluminum oxide film 106.
[0019] According to one embodiment, alternating gas exposures can be repeated after deposition selectivity is lost, thereby depositing aluminum oxide on the surface 104A of the metal or semiconductor layer 104 as well. The resulting covered aluminum oxide film 107 is illustrated in FIG. 1C, wherein the aluminum oxide is deposited over the entire substrate 1. Since the deposition of aluminum oxide on surface 104A requires a longer incubation time, the aluminum oxide film 107 on surface 100A can be thicker than that on surface 104A.
[0020] For example, aluminum alkane gases may include trimethylaluminum (Al(CH3)3), triethylaluminum (Al(CH2CH3)3), tripropylaluminum (Al(CH2CH2CH3)3), or triisobutylaluminum (Al(CH2CH(CH3))2)3). For example, aluminum halides may include AlCl3, AlF3, AlBr3, or AlI3. For example, aluminum hydrides may include AlH3.
[0021] For example, aluminum alkoxide may include aluminum isopropoxide (Al(OCH(CH3)2)3, aluminum triethanolamine (Al(OCH3)3), aluminum triethanolamine (Al(OCH2CH3)3), and dialkylaluminum alkoxide. Dialkylaluminum alkoxide may include, for example, dimethylaluminum isopropoxide ((CH3)2AlOCH(CH3)2), dimethylaluminum tert-butanol ((CH3)2AlOC(CH3)3), diethylaluminum isopropoxide ((CH3CH2)2AlOCH(CH3)2), dimethylaluminum sec-butanol ((CH3)2AlOCHCH3(CH2CH3)), or aluminum diethylethanolamine ((CH3CH2)2AlOCH2CH3).
[0022] Figures 2A-2D are schematic cross-sectional views illustrating a process for depositing an aluminum oxide film on a substrate according to an embodiment of the present invention. The substrate 1 in Figure 1A has been replicated as the substrate 2 in Figure 2A. The method includes exposing the substrate 2 to a molecularly-containing reactive gas that selectively forms a self-assembled monolayer (SAM) 108 on the surface 104A of a metal or semiconductor layer 104. This is schematically shown in Figure 2B.
[0023] SAMs are molecular assemblies that spontaneously form on a substrate surface via adsorption and are organized into ordered domains of roughly the same size. SAMs may include molecules having head groups, tail groups, and functional end groups, and are generated by the following process: at room temperature or above, head groups are chemically adsorbed onto the substrate in the gas phase, followed by slow organization of tail groups. Initially, at a low molecular density on the surface, the adsorbed molecules form disordered masses of molecules or ordered two-dimensional "lying-down phases," and under higher molecular coverage, over several minutes to several hours, three-dimensional crystalline or semi-crystalline structures begin to form on the substrate surface. Head groups assemble together on the substrate, while tail groups assemble at locations away from the substrate. According to one embodiment, the head groups of the molecules forming SAM108 may include thiols, phosphonates, silanes, or carboxylates. For example, thiols may include 1-octadecylthiols (CH3(CH2)17SH), 1-dodecylthiols (CH3(CH2)17SH), or perfluorodecylthiols (CF3(CF2)7CH2CH2SH).
[0024] The method further includes selectively depositing an aluminum oxide film 110 on the surface 100A of the dielectric layer 100 by ALD relative to SAM108, wherein SAM108 serves as a deposition barrier layer. This is schematically shown in FIG2C. ALD includes exposing the substrate to an aluminum alkane gas, an aluminum halide gas, or an aluminum hydride gas to form an aluminum-containing adsorption layer on the surface 100A, and subsequently exposing the substrate to an aluminum alkane gas that reacts with the adsorption layer to form the aluminum oxide film 110. The aluminum alkane gas is the primary source of oxygen in the deposited aluminum oxide film 110, and the reaction involves the coordination of oxygen atoms of alkoxy groups to the aluminum metal center of the adsorption layer.
[0025] The selective deposition of the aluminum oxide film 110 on the surface 100A of the dielectric layer 100 relative to the surface 104A of the metal or semiconductor layer 104 containing SAM108 is achieved by increasing the deposition incubation time on SAM108 or on defects in SAM108 compared to a clean surface 104A of the metal or semiconductor layer 104. Alternating gas exposures can be repeated at least once while maintaining the selectivity of deposition to increase the thickness of the aluminum oxide film 110.
[0026] Subsequently, SAM108 can be removed to produce the substrate shown in FIG. 2D, wherein an aluminum oxide film 110 is selectively formed on surface 100A. In one example, SAM108 can be removed by heating. According to other embodiments, other types of barrier layers besides SAM can be used, such as aniline, acetylacetone, and acetylacetone-based chemicals.
[0027] Figures 3A-3D are schematic cross-sectional views illustrating a method for depositing an aluminum oxide film on a substrate according to an embodiment of the present invention. The substrate 1 in Figure 1A has been replicated as the substrate 3 in Figure 3A. The method includes exposing the substrate 3 to a molecularly-containing reactive gas that selectively forms a self-assembled monolayer (SAM) 112 on the surface 100A of the dielectric layer 100. This is schematically shown in Figure 3B.
[0028] According to one embodiment, the head group of the molecule forming SAM112 may include silane. Examples of silanes include molecules containing C, H, Cl, F, and Si atoms, or C, H, Cl, and Si atoms. Non-limiting examples of molecules include perfluorodecyltrichlorosilane (CF3(CF2)7CH2CH2SiCl3), chlorodecyl dimethylsilane (CH3(CH2)8CH2Si(CH3)2Cl), and tert-butyl(chloro)dimethylsilane ((CH3)3CSi(CH3)2Cl).
[0029] The method further includes, relative to SAM112, selectively depositing an aluminum oxide film 114 on the surface 104A of the metal or semiconductor layer 104 by ALD. This is schematically shown in FIG3C. ALD includes exposing the substrate to an aluminum alkane gas, an aluminum halide gas, or an aluminum hydride gas to form an aluminum-containing adsorption layer on the surface 104A, and subsequently exposing the substrate to an aluminum alkane gas, wherein the aluminum alkane gas is the primary source of oxygen in the deposited aluminum oxide film 114.
[0030] The selective deposition of the aluminum oxide film 114 on the surface 104A of the metal or semiconductor layer 104 relative to the surface 100A of the dielectric layer 100 is achieved by blocking deposition on the SAM 112. Alternating gas exposure can be repeated at least once while maintaining the selectivity of deposition to increase the thickness of the aluminum oxide film 114.
[0031] Subsequently, SAM112 can be removed to produce substrate 3 as shown in FIG. 2D, wherein an aluminum oxide film 114 is selectively formed on surface 104A. According to one embodiment, other types of barrier layers besides SAM can be used, such as aniline, acetylacetone, and acetylacetone-based chemicals.
[0032] Figures 4A-4F are schematic cross-sectional views of a method for depositing an aluminum oxide film on a substrate according to an embodiment of the present invention. As schematically shown in Figure 4A, the method includes providing a substrate 4 including a first film 402 and a second film 400. The first film 402 includes a raised feature having a top 401 and a recessed feature 404 having sidewalls 408 and a bottom region 406. The recessed feature 404 may, for example, have a width 407 of less than 200 nm, less than 100 nm, less than 50 nm, less than 25 nm, less than 20 nm, or less than 10 nm. In other examples, the recessed feature 404 may have a width 407 between 5 nm and 10 nm, between 10 nm and 20 nm, between 20 nm and 50 nm, between 50 nm and 100 nm, between 100 nm and 200 nm, between 10 nm and 50 nm, or between 10 nm and 100 nm. The recessed feature 404 may have a depth 409 of, for example, 25 nm, 50 nm, 100 nm, 200 nm or greater.
[0033] In some examples, the first film 402 and the second film 400 may include or be composed of the same material. In one example, the first film 402 and the second film 400 may include or be composed of Si. In some examples, the first film 402 may include a dielectric layer, such as SiO2, SiON, SiN, a high-k material, a low-k material, or an ultra-low-k material. The recessed feature 404 may be formed using well-known lithography and etching processes.
[0034] The method further includes depositing an aluminum oxide film on the raised feature portion, wherein the aluminum oxide film is deposited in a non-conformal manner, having a larger film thickness on the top 401 compared to the sidewalls 408 and the bottom region 406. The aluminum oxide film is deposited by exposing the substrate 4 to an aluminum alkane gas, an aluminum halide gas, or an aluminum hydride gas, forming a conformal adsorption layer 410 on the raised feature portion. The exposure conditions can be selected to achieve saturation exposure, wherein the aluminum alkane gas, aluminum halide gas, or aluminum hydride gas reaches the bottom region 406 of the recessed feature portion 404 and forms the adsorption layer 410, as schematically shown by the hollow circle 410 in FIG4B.
[0035] Subsequently, the method further includes exposing the substrate 4 to an alkane alumina gas, wherein the exposure conditions are selected such that saturation exposure is not achieved in the recessed feature 404, and the alkane alumina gas does not reach the bottom region 406 between the raised features, and is only exposed to the adsorption layer 410 on the top 401 and the upper part of the sidewall 408, wherein the alkane alumina gas reacts with the adsorption layer 410 to form an aluminum oxide film 412. This is schematically shown in FIG. 4C. Processing conditions, such as substrate temperature, gas pressure, gas composition, and substrate rotation during gas exposure, can be selected to achieve unsaturated exposure in the recessed feature 404.
[0036] Subsequently, any unreacted portion of the adsorbed layer 410 in the recessed feature 404 can be removed, for example, by heating. The resulting substrate 4 is schematically shown in FIG. 4D. The alternating steps of exposing the substrate 4 to aluminum alkane gas, aluminum halide gas, or aluminum hydride gas, and subsequently aluminum alkane oxide gas can be repeated at least once to increase the thickness of the aluminum oxide film 412 on the top 401 and the upper part of the sidewall 408. This is schematically shown in FIG. 4E. Further, as shown in FIG. 4F, after repeating the exposure step at least once, the resulting aluminum oxide film 412 can clamp the opening of the recessed feature 404, and a closed gas gap is formed in the recessed feature 404 below the aluminum oxide film 412.
[0037] Figures 5A-5F are schematic cross-sectional views illustrating a method for depositing an aluminum oxide film on a substrate according to an embodiment of the present invention. The substrate 4 in Figures 4A and 4B has been replicated as the substrate 5 in Figures 5A and 5B, respectively. After the substrate 5 is exposed to an aluminum alkane gas, an aluminum halide gas, or an aluminum hydride gas, the substrate 5 includes a conformal adsorption layer 410 on a raised feature. The method includes exposing the substrate 5 in Figure 5B to a halogen-containing gas or an oxygen-containing gas to deactivate the adsorption layer 410, or removing the adsorption layer 410 from the top 401 and the upper portion of the sidewall 408. Exposure to the halogen-containing gas or oxygen-containing gas does not reach the lower portion or bottom region 406 of the sidewall 408. Figure 5C schematically shows the deactivated layer 405 formed by gas exposure, indicated by a shaded circle. Gas exposure can be performed without plasma or in the presence of plasma excitation. Processing conditions, such as substrate temperature, gas pressure, gas composition, and substrate rotation during gas exposure, can be selected to control the deactivation of the adsorption layer 410. In some examples, highly diluted halogen-containing gases and high total gas pressures (e.g., greater than about 1 Torr) can be used to provide highly isotropic exposure of the halogen-containing gases.
[0038] Non-limiting examples of halogen-containing gases include Cl2, BCl3, CCl4, HCl, HBr, TiCl4, and combinations thereof. Non-limiting examples of oxygen-containing gases include O3, O2, H2O, H2O2, and combinations thereof. Halogen-containing gases and oxygen-containing gases may further include inert gases, such as argon (Ar).
[0039] Subsequently, the method further includes exposing the substrate 5 to an alkane alumina gas, thereby reacting with the adsorption layer 410 on the sidewall 408 below the deactivation layer 405 and the adsorption layer 410 on the bottom region 406 to form an aluminum oxide film 414, but not forming an aluminum oxide film 412 on the deactivation layer 405. This is schematically shown in FIG5D. The exposure conditions can be selected to achieve saturation exposure, wherein the alkane alumina gas reaches the lower part of the sidewall 408 of the recessed feature portion 410 and reaches the bottom region 406.
[0040] Subsequently, the deactivation layer 405 can be removed, for example, by heating. This is schematically shown in FIG. 5E. The alternating exposure steps can be repeated at least once to increase the thickness of the aluminum oxide film 412 in the recessed feature 404. In the example schematically shown in FIG. 5F, after repeating the alternating exposure steps at least once, the recessed feature 410 is substantially completely filled with the aluminum oxide film 414.
[0041] In many embodiments, methods for depositing aluminum oxide films using an anhydrous oxidant have been disclosed. The foregoing description of embodiments of the present invention has been presented for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. This description and the following claims include language used for descriptive purposes only and should not be construed as restrictive. Those skilled in the art will appreciate that many modifications and variations are possible in light of the foregoing teachings. Those skilled in the art will recognize many equivalent combinations and substitutions of the various elements shown in the figures. Therefore, the scope of the invention is intended to be limited not by this detailed description, but by the appended claims. [Simplified Explanation of the Diagram]
[0009] A more complete understanding of the embodiments of the invention and its many accompanying advantages will become apparent when the following detailed description is taken, particularly in conjunction with the accompanying drawings, in which:
[0010] Figures 1A-1C are schematic cross-sectional views showing the process of depositing an aluminum oxide film on a substrate according to an embodiment of the present invention.
[0011] Figures 2A-2D are schematic cross-sectional views of a method for depositing an aluminum oxide film on a substrate according to an embodiment of the present invention.
[0012] Figures 3A-3D are schematic cross-sectional views showing the process of depositing an aluminum oxide film on a substrate according to an embodiment of the present invention.
[0013] Figures 4A-4F are schematic cross-sectional views illustrating a method for depositing an aluminum oxide film on a substrate according to an embodiment of the present invention.
[0014] Figures 5A-5F are schematic cross-sectional views of a method for depositing an aluminum oxide film on a substrate according to an embodiment of the present invention.
Claims
1. A substrate processing method, comprising: A substrate is provided, the substrate including a dielectric layer and a metal layer or a semiconductor layer; And, relative to one surface of the metal layer or one surface of the semiconductor layer, an aluminum oxide film is selectively deposited on one surface of the dielectric layer by: a) exposing the substrate to aluminum alkane gas, aluminum halide gas or aluminum hydride gas, and b) exposing the substrate to aluminum alkane gas, wherein the aluminum alkane gas is the main source of oxygen in the aluminum oxide film.
2. The substrate processing method of claim 1 further includes: c) Repeat steps a) and b) at least once to increase the thickness of the aluminum oxide film on the surface of the dielectric layer.
3. The substrate processing method of claim 2, wherein step c) results in a loss of deposition selectivity and a covering aluminum oxide film is formed on the surface of the dielectric layer and on the surface of the metal layer or on the surface of the semiconductor layer.
4. The substrate processing method of claim 1 further includes: Before selectively depositing the aluminum oxide film, the substrate is exposed to a molecular reactive gas that forms a self-assembled monolayer on the surface of the metal layer or the surface of the semiconductor layer.
5. The substrate processing method of claim 4, wherein the molecule includes a head group, a tail group and a functional end group, and wherein the head group includes a thiol, a silane, a phosphonate or a carboxylate.
6. The substrate processing method of claim 1, wherein the aluminum alkane gas includes trimethylaluminum (Al(CH3)3), triethylaluminum (Al(CH2CH3)3), tripropylaluminum (Al(CH2CH2CH3)3), or triisobutylaluminum (Al(CH2CH(CH3)2)3), the aluminum halide gas includes AlCl3, AlF3, AlBr3, or AlI3, the aluminum hydride gas includes AlH3, and the aluminum alkane gas includes aluminum isopropoxide (Al(OCH(CH3)2)).
3. Aluminum triethanolamine (Al(OCH3)3), dimethylaluminum isopropanol ((CH3)2AlOCH(CH3)2), dimethylaluminum tert-butanol ((CH3)AlOC(CH3)3), diethylaluminum isopropanol ((CH3CH2)2AlOCH(CH3)2), dimethylaluminum sec-butanol ((CH3)AlOCHCH3(CH2CH3)), aluminum triethanolamine (Al(OCH2CH3)3) or aluminum diethylethanolamine ((CH3CH2)2AlOCH2CH3).
7. A substrate processing method, comprising: A substrate is provided, the substrate including a dielectric layer and a metal layer or a semiconductor layer; And, relative to one surface of the dielectric layer, an aluminum oxide film is selectively deposited on one surface of the metal layer or on one surface of the semiconductor layer by: a) exposing the substrate to a molecular reactive gas, the reactive gas forming a self-assembled monolayer on the surface of the dielectric layer; b) exposing the substrate to an aluminum alkane gas, an aluminum halide gas or an aluminum hydride gas; and c) exposing the substrate to an aluminum alkane gas, wherein the aluminum alkane gas is the primary source of oxygen in the aluminum oxide film.
8. The substrate processing method as described in claim 7 further includes: d) Repeat steps a), b) and c) at least once to increase the thickness of the aluminum oxide film on the surface of the metal layer or the surface of the semiconductor layer.
9. The substrate processing method of claim 7, wherein the molecule includes a head group, a tail group and a functional end group, and wherein the head group includes silane.
10. The substrate processing method of claim 7, wherein the aluminum alkane gas includes trimethylaluminum (Al(CH3)3), triethylaluminum (Al(CH2CH3)3), tripropylaluminum (Al(CH2CH2CH3)3), or triisobutylaluminum (Al(CH2CH(CH3)2)3), the aluminum halide gas includes AlCl3, AlF3, AlBr3, or AlI3, the aluminum hydride gas includes AlH3, and the aluminum alkane gas includes aluminum isopropoxide (Al(OCH(CH3)2)).
3. Aluminum triethanolamine (Al(OCH3)3), dimethylaluminum isopropanol ((CH3)2AlOCH(CH3)2), dimethylaluminum tert-butanol ((CH3)AlOC(CH3)3), diethylaluminum isopropanol ((CH3CH2)2AlOCH(CH3)2), dimethylaluminum sec-butanol ((CH3)AlOCHCH3(CH2CH3)), aluminum triethanolamine (Al(OCH2CH3)3) or aluminum diethylethanolamine ((CH3CH2)2AlOCH2CH3).
11. A substrate processing method, comprising: A substrate is provided, the substrate including a plurality of raised features and a bottom region, the raised features having sidewalls and a top, the bottom region being located between the raised features; and an aluminum oxide film is selectively deposited on the top and an upper portion of the sidewall of the raised features relative to the bottom region, by: a) exposing the substrate to an aluminum alkane gas, an aluminum halide gas or an aluminum hydride gas to form a conformal adsorption layer on the raised features; and b) exposing the substrate to an aluminum alkane gas, wherein the aluminum alkane gas is the primary source of oxygen in the aluminum oxide film.
12. The substrate processing method of claim 11 further includes: c) Repeat steps a) and b) at least once to increase the thickness of the aluminum oxide film.
13. The substrate processing method of claim 12, wherein the aluminum oxide film clamps an opening between the protruding features and forms a gas gap.
14. The substrate processing method of claim 11, wherein during step b), the alkane alumina gas does not reach the bottom region between the raised features.
15. The substrate processing method of claim 11, wherein the aluminum alkoxide gas comprises trimethylaluminum (Al(CH3)3), triethylaluminum (Al(CH2CH3)3), tripropylaluminum (Al(CH2CH2CH3)3), or triisobutylaluminum (Al(CH2CH(CH3)2)3), the aluminum halide gas comprises AlCl3, AlF3, AlBr3, or AlI3, the aluminum hydride gas comprises AlH3, and the aluminum alkoxide gas comprises aluminum isopropoxide (Al(OCH(CH3)2)3).
3. Aluminum triethanolamine (Al(OCH3)3), dimethylaluminum isopropanol ((CH3)2AlOCH(CH3)2), dimethylaluminum tert-butanol ((CH3)AlOC(CH3)3), diethylaluminum isopropanol ((CH3CH2)2AlOCH(CH3)2), dimethylaluminum sec-butanol ((CH3)AlOCHCH3(CH2CH3)), aluminum triethanolamine (Al(OCH2CH3)3) or aluminum diethylethanolamine ((CH3CH2)2AlOCH2CH3).
16. A substrate processing method, comprising: A substrate is provided, the substrate including a plurality of raised features and a bottom region, the raised features having sidewalls and a top, the bottom region being located between the raised features; and an aluminum oxide film is selectively deposited on the sidewalls and the bottom region relative to the top by: a) exposing the substrate to an aluminum alkane gas, an aluminum halide gas or an aluminum hydride gas to form a conformal adsorption layer on the raised features; b) deactivating or removing the adsorption layer on the top; and c) exposing the substrate to an aluminum alkane gas, wherein the aluminum alkane gas is the primary source of oxygen in the aluminum oxide film.
17. The substrate processing method of claim 16 further includes: d) Repeat steps a), b) and c) at least once to increase the thickness of the aluminum oxide film.
18. The substrate processing method of claim 16, wherein the aluminum oxide film at least substantially completely fills a recessed feature between the raised features.
19. The substrate processing method of claim 16, wherein the step of deactivating or removing the adsorbed layer includes exposing the substrate to a halogen-containing gas or an oxygen-containing gas.
20. The substrate processing method of claim 19, wherein the halogen-containing gas includes Cl2, BCl3, CCl4, HCl, HBr, TiCl4 or combinations thereof, and the oxygen-containing gas includes O3, O2, H2O, H2O2 or combinations thereof.
21. The substrate processing method of claim 16, wherein the aluminum alkoxide gas comprises trimethylaluminum (Al(CH3)3), triethylaluminum (Al(CH2CH3)3), tripropylaluminum (Al(CH2CH2CH3)3), or triisobutylaluminum (Al(CH2CH(CH3)2)3), the aluminum halide gas comprises AlCl3, AlF3, AlBr3, or AlI3, the aluminum hydride gas comprises AlH3, and the aluminum alkoxide gas comprises aluminum isopropoxide (Al(OCH(CH3)2)3).
3. Aluminum triethanolamine (Al(OCH3)3), dimethylaluminum isopropanol ((CH3)2AlOCH(CH3)2), dimethylaluminum tert-butanol ((CH3)AlOC(CH3)3), diethylaluminum isopropanol ((CH3CH2)2AlOCH(CH3)2), dimethylaluminum sec-butanol ((CH3)AlOCHCH3(CH2CH3)), aluminum triethanolamine (Al(OCH2CH3)3) or aluminum diethylethanolamine ((CH3CH2)2AlOCH2CH3).