Methods and non-transitory computer readable storage medium for processing a substrate

Abstract

This document provides methods and apparatus for processing a substrate. For example, the method for processing a substrate includes the steps of: depositing a silicate layer in a feature defined in a layer on a substrate; forming a metal liner layer or a metal seed layer on top of the silicate layer in the feature by depositing at least one of molybdenum (Mo) or tungsten (W) using physical vapor deposition; and depositing Mo on top of the at least one of the metal liner layer or the metal seed layer using at least one of chemical vapor deposition or atomic layer deposition, without vacuum destruction.

Description

[Technical Field]

[0001] The embodiments of this disclosure are generally related to methods and apparatus for processing substrates, and more specifically, to methods and apparatus for integrating low resistivity intermediate terminal (MEOL) metallization. [Previous Technology]

[0002] Conventional MEOL metallization processes typically involve forming one or more metal film stacks on a substrate, which may include features recessed from field areas on the substrate (e.g., vias, trenches, etc.). For example, in some cases, a metal liner layer or a metal seed layer may be deposited within the features on the substrate using, for example, physical vapor deposition (PVD). The substrate can then be transferred from the PVD processing chamber (reactor) to another processing chamber (reactor) where subsequent metal layers may be deposited using, for example, chemical vapor deposition (CVD) and / or atomic layer deposition (ALD). However, during the transfer from the PVD processing chamber to the CVD and / or ALD processing chamber, oxidation may sometimes develop on the metal liner layer or metal seed layer. Accordingly, one or more oxidation processes may be performed to remove the oxidation (e.g., to improve gap-filling performance and reduce the stack resistivity of the fabricated substrate). It is understood that performing one or more oxidation processes increases manufacturing costs and reduces production volume. [Summary of the Invention]

[0003] This document provides methods and apparatus for processing a substrate (e.g., metal-filled). For example, the method for processing a substrate includes the steps of: depositing a silicate layer in a feature defined in a layer on a substrate; forming a metal liner layer or a metal seed layer on top of the silicate layer in the feature by depositing at least one of molybdenum (Mo) or tungsten (W) using physical vapor deposition; and depositing Mo on top of the at least one of the metal liner layer or the metal seed layer using at least one of chemical vapor deposition or atomic layer deposition, without vacuum destruction.

[0004] According to at least some embodiments, a non-transitory computer-readable storage medium has instructions stored thereon that, when executed by a processor, perform a method for processing a substrate, the method comprising the steps of: depositing a silicate layer in a feature defined in a layer on a substrate; forming a metal liner layer or a metal seed layer on top of the silicate layer in the feature by means of at least one of molybdenum (Mo) or tungsten (W) using physical vapor deposition; and depositing Mo on top of the at least one of the metal liner layer or the metal seed layer using at least one of chemical vapor deposition or atomic layer deposition, without vacuum disruption.

[0005] According to at least some embodiments, a method for processing a substrate includes the following steps: performing a pre-cleaning process on a substrate, the substrate including a layer having a feature defined therein; forming a metal liner layer or a metal seed layer within the feature using physical vapor deposition via deposition of at least one of molybdenum (Mo) or tungsten (W); depositing a nucleation layer on top of the metal liner layer or the metal seed layer; and depositing Mo on top of the metal liner layer or the metal seed layer using at least one of chemical vapor deposition or atomic layer deposition to selectively fill or conformally fill the feature without vacuum destruction.

[0006] Other and further embodiments of this disclosure are described below.

Implementation Method

[0013] This document provides embodiments of methods and apparatus for processing substrates. For example, in at least some embodiments, the methods and apparatus described herein are configured to deposit a silicon layer within a feature defined in a layer on a substrate. Next, a metal pad layer or a metal seed layer may be deposited within the feature. For example, in at least some embodiments, PVD may be used to deposit the metal pad layer or metal seed layer within the feature. Subsequently, one or more additional metals may be deposited on the metal pad layer or metal seed layer. For example, in at least some embodiments, CVD and / or ALD may be used to deposit one or more additional metals on top of the metal pad layer or metal seed layer without vacuum destruction, which substantially reduces (if not eliminates) oxidation caused by formation on the metal pad layer or metal seed layer. Accordingly, conventional oxidation processes do not need to be used in conjunction with the methods described herein, which in turn leads to a reduction in overall substrate manufacturing costs and an increase in production volume compared to conventional manufacturing processes.

[0014] FIG1 is a flowchart of a method 100 for processing a substrate according to at least some embodiments of the present disclosure, and FIG2 is a tool 200 (or device) that can be used to implement method 100.

[0015] Method 100 can be performed in tool 200, including configuring any suitable processing chamber for one or more of physical vapor deposition (PVD), chemical vapor deposition (CVD), and / or atomic layer deposition (ALD), such as plasma-enhanced ALD or thermal ALD (e.g., plasma-free). Exemplary processing systems that can be used to perform the methods of the invention disclosed herein are available from Applied Materials, Inc., Santa Clara, California. Other processing chambers (including those from other manufacturers) may also be used appropriately in conjunction with the teachings provided herein.

[0016] Tool 200 may be embodied in a separate processing chamber, which may be configured independently or provided as part of a cluster of tools, such as the integrated tool described below with reference to FIG2. Examples of integrated tools include the integrated tool family available from Applied Materials, Inc., Santa Clara, California. The methods described herein may be implemented using other cluster tools having suitable processing chambers coupled thereto or in other suitable processing chambers. For example, in some embodiments, the methods of the invention discussed above may be performed in an integrated tool such that there is limited or no vacuum disruption between processing steps. For example, reduced vacuum disruption may limit or prevent contamination (e.g., oxidation) of the metal liner layer, metal seed layer, or other portions of the substrate.

[0017] The integrated tool includes a processing platform 201 (vacuum sealing processing platform), a factory interface 204, and a system controller 202. The processing platform 201 includes multiple processing chambers, such as 214A, 214B, 214C, and 214D, operatively coupled to a transfer chamber 203 (vacuum substrate transfer chamber). The factory interface 204 is operatively coupled to the transfer chamber 203 via one or more loading gate chambers (two loading gate chambers, such as 206A and 206B shown in FIG. 2).

[0018] In some embodiments, the fab interface 204 includes a docking station 207 and a fab interface robot 238 to facilitate the transfer of substrate 221 (wafer). The docking station 207 is configured to accept one or more front-opening wafer pods (FOUPs). The embodiment of FIG2 shows four FOUPs, such as 205A, 205B, 205C, and 205D. The fab interface robot 238 is configured to transfer substrate 221 from the fab interface 204 to the processing platform 201 via loading gate chambers (e.g., 206A and 206B). Each of the loading gate chambers 206A and 206B has a first port coupled to the fab interface 204 and a second port coupled to the transfer chamber 203. Loading gate chambers 206A and 206B are coupled to a pressure control system (not shown) that evacuates and ventilates the loading gate chambers 206A and 206B to facilitate the passage of substrate 221 between the vacuum environment of transfer chamber 203 and the physical surrounding environment (e.g., atmosphere) of the plant interface 204. Transfer chamber 203 has a vacuum robot 242 disposed within it. The vacuum robot 242 is capable of transferring substrate 221 between loading gate chambers 206A and 206B and processing chambers 214A, 214B, 214C, and 214D.

[0019] The processing chambers 214A, 214B, 214C and 214D include at least an ALD chamber, a CVD chamber, a PVD chamber, an electron beam deposition chamber, a pre-cleaning chamber, and / or an electroplating or electroless deposition (EEP) chamber.

[0020] In some embodiments, one or more optional service chambers (shown as 216A and 216B) may be coupled to transfer chamber 203. Service chambers 216A and 216B may be configured to perform other substrate processes, such as degassing, bonding, chemical mechanical polishing (CMP), wafer dicing, etching, plasma slicing, orientation, substrate metering, cooling, etc.

[0021] The system controller 202 controls the operation of the tool 200 by directly controlling the processing chambers 214A, 214B, 214C, and 214D, or alternatively by controlling a computer (or controller) associated with the processing chambers 214A, 214B, 214C, 214D and the tool 200. During operation, the system controller 202 can collect data and feedback from the respective chambers and systems to optimize the performance of the tool 200. The system controller 202 typically includes a central processing unit 230, memory 234, and support circuitry 232. The central processing unit 230 can be any type of general-purpose computer processor that can be used in an industrial environment. The support circuitry 232 is conventionally coupled to the central processing unit 230 and may include cache, clock circuitry, input / output subsystems, power supply, etc. Software routines (such as the processing methods described herein) may be stored in memory 234 (e.g., a non-transitory computer-readable storage medium on which instructions are stored), and when executed by central processing unit 230, central processing unit 230 is converted into a dedicated computer (system controller 202). Software routines may also be stored and / or executed by a second controller (not shown) located remotely at the end of tool 200.

[0022] Continuing to refer to FIG1 and FIG3, initially one or more substrates 300 (e.g., substrate 221) may be loaded into one or more of the four FOUPs, such as 205A, 205B, 205C, and 205D (FIG. 3A). For example, in at least some embodiments, substrate 300 may include a base layer 302, which may be made of one or more materials suitable for providing field layer 304 thereon. For example, in at least some embodiments, base layer 302 may be formed of at least one of the following: silicon, glass, or a metal substrate made of aluminum, copper, stainless steel, tungsten, titanium, molybdenum, cobalt, etc. Similarly, field layer 304 may be formed of one or more dielectrics. For example, in at least some embodiments, field layer 304 may be a dielectric, such as silicon oxide or silicon nitride. One or more features 306 (e.g., trenches, vias, or dual damascene structures) may be recessed in field layer 304. One or more features 306 may have a first sidewall 308 and an opposing second sidewall 310.

[0023] Once loaded, the factory interface robot 238 can transfer the substrate 300 from the factory interface 204 to the processing platform 201 via, for example, the loading gate chamber 206A. The vacuum robot 242 can transfer the substrate 300 from the loading gate chamber 206A into and out of one or more of the processing chambers 214A to 214D and / or the service chambers 216A and 216B.

[0024] In at least some embodiments, method 100 may include performing an optional pre-cleaning process on the substrate, wherein the pre-cleaning process uses at least one of hydrogen plasma or fluorine plasma, and wherein one of a capacitively coupled plasma source, an inductively coupled plasma source, or a remote plasma source is used to form the hydrogen plasma or fluorine plasma. For example, a vacuum robot 242 may transport the substrate to a processing chamber 214A.

[0025] Next, in at least some embodiments, at 102, method 100 may optionally deposit a silica layer 318 / 418, the silica layer 318 / 418 including at least one of the following within features defined in a layer (e.g., field layer 304) on substrate 300 (e.g., see FIG. 3A): silane (SiH4) and cobalt (Co), SiH4 and Mo, SiH4 and ruthenium (Ru), or SiH4 and W. For example, vacuum robot 242 may transfer the substrate from processing chamber 214A to processing chamber 214B (with or without vacuum disruption), allowing the silica layer to be deposited using CVD and / or ALD. Next, in at least some embodiments, method 100 includes performing PVD to optionally deposit a metal capping layer 320, 420 within features on top of the silica layer, the metal capping layer 320, 420 including at least one of: Co, Mo, Ru, or W. For example, vacuum robot 242 can transfer a substrate from processing chamber 214B to processing chamber 214C (with or without vacuum disruption). In such an embodiment, the metal capping layer may have a thickness of about 30 Å to about 100 Å, for example, 60 Å. Next, method 100 includes optionally performing at least one of ALD and / or CVD to deposit Mo layers 322, 422 on top of the metal capping layers 320, 420 within the features without vacuum disruption. For example, vacuum robot 242 can transfer the substrate from processing chamber 214C back to processing chamber 214B (with or without vacuum disruption).

[0026] At 104, method 100 includes forming one of a metal pad layer or a metal seed layer within a defined feature in a layer on a substrate by depositing at least one or more metals using PVD (FIG 3B). For example, in at least some embodiments, a factory interface robot 238 may transport (with or without vacuum disruption) the substrate 300 to a processing chamber 214C to deposit a metal pad layer 312 on a field layer 304 via PVD. In at least some embodiments, the metal pad layer may be molybdenum (Mo) and / or tungsten (W), or other suitable metals. At 104, processing parameters may include a pressure providing about 100 mTorr to about 400 mTorr, a temperature of about room temperature to about 400 degrees Celsius, an RF power of about 1,000 W to about 40,000 W (e.g., at a frequency of about 40 MHz), and an RF bias of about 50 W to about 200 W (e.g., at an RF frequency of 13.56 MHz). The metal liner layer 312 may be deposited to cover at least a portion of the top surface of the first sidewall 308, the second sidewall 310, the top surface of the base layer 302 or the bottom surface of the feature 306, and the top surface 314 of the field layer 304. In at least some embodiments, the metal liner layer 312 may be deposited to cover the silicate layer 318 in use.

[0027] Alternatively, in at least some embodiments, at 104, the metal seed layer 412 may be deposited on the top surface of the base layer 402 (e.g., base layer 302) of the substrate 400 or on the bottom surface of the feature 406 recessed in the field layer 404 (e.g., field layer 404), and may have a first sidewall 408 and an opposing second sidewall 410 (FIGs 4A and 4B). In at least some embodiments, the metal seed layer 412 may be deposited to cover the silicate layer 418 in use. The metal seed layer 412 may be performed under the same processing parameters as the metal pad layer 312.

[0028] Next, at 106, method 100 includes depositing Mo on top of at least one of the metal pad layer or metal seed layer using at least one of CVD or ALD without vacuum disruption. In at least some embodiments, 106 can be performed without first performing redox by exposing at least one of Mo or W to hydrogen, for example, by maintaining a vacuum. A factory interface robot 238 can transport the substrate 300 from processing chamber 214C to processing chamber 214B to deposit Mo via CVD and / or ALD. In at least some embodiments, Mo is deposited on top of the metal pad layer 312 via CVD and / or ALD to conformally fill feature 306 (FIG. 3C). For example, Mo is deposited to cover or substantially cover the metal pad layer 312 (e.g., the metal pad layer 312 is deposited on the top surface of the first sidewall 308, the second sidewall 310, the base layer 302 or the bottom surface of feature 306, and the top surface 314 of the field layer 304). At point 106, the processing parameters may include a pressure of about 10 Torr to about 60 Torr, a temperature of about 350 degrees Celsius to about 400 degrees Celsius, a nozzle-to-substrate spacing of about 190 mil to about 450 mil, and a flow precursor of argon carrier gas with a flow rate of about 500 sccm to about 3000 sccm and hydrogen reaction gas with a flow rate of about 1000 sccm to about 10000 sccm.

[0029] Alternatively, in at least some embodiments, Mo is deposited on top of the metal seed layer 412 via CVD and / or ALD to selectively fill the feature 406 (FIG. 4C), for example to develop / grow Mo on the metal seed layer 412 and / or enhance the gap filling performance.

[0030] In at least some embodiments, prior to 106, method 100 includes depositing a nucleation layer (nucleation layer 316 or nucleation layer 416) on top of either the metal liner layer 312 or the metal seed layer 412 (shown by the dashed lines in Figures 3B and 4B). For example, the nucleation layer may be deposited at 104 during CVD or ALD to promote Mo growth.

[0031] In at least some embodiments, after step 106, method 100 includes performing PVD to deposit additional Mo on top of Mo deposited on top of either a metal liner layer or a metal seed layer, to selectively fill or conformally fill one of the features without vacuum destruction. In such embodiments, the additional Mo may be deposited to a thickness of about 2000 Å. In at least some embodiments, after PVD deposition of the additional Mo, method 100 includes performing chemical mechanical polishing on the additional Mo.

[0032] Although the foregoing content pertains to embodiments of this disclosure, other and further embodiments of this disclosure may be designed without departing from its basic scope. [Simplified Explanation of the Diagram]

[0007] The embodiments of this disclosure, which are briefly summarized above and discussed in more detail below, can be understood by referring to the illustrative embodiments of this disclosure depicted in the accompanying drawings. However, the drawings only illustrate typical embodiments of this disclosure and should therefore not be considered as limiting the scope, as other equivalent embodiments are permissible in this disclosure.

[0008] FIG1 is a flowchart of a method for processing a substrate according to at least some embodiments of the present disclosure.

[0009] FIG2 is a schematic diagram of an apparatus for processing a substrate according to at least some embodiments of the present disclosure.

[0010] Figures 3A to 3C are diagrams illustrating the processing sequence of the method of Figure 1 according to at least some embodiments of the present disclosure.

[0011] Figures 4A to 4C are diagrams illustrating the processing sequence of the method of Figure 1 according to at least some embodiments of the present disclosure.

[0012] For ease of understanding, the same reference numerals are used as much as possible to represent common elements in the drawings. The drawings are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be advantageously incorporated into other embodiments without further description. [Biomaterial Storage]

[0034] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A method for processing a substrate, comprising the steps of: depositing a silicate layer in a feature defined in a layer on a substrate; forming a metal liner layer or a metal seed layer on top of the silicate layer in the feature by means of physical vapor deposition of at least one of molybdenum (Mo) or tungsten (W); and depositing Mo on top of the at least one of the metal liner layer or the metal seed layer by means of at least one of chemical vapor deposition or atomic layer deposition, without vacuum destruction.

2. The method as described in claim 1, wherein the feature is one of a trench, a through hole, or a dual damascene structure, and wherein the Mo is deposited on top of one of the metal liner layer or the metal seed layer to selectively fill or conformally fill one of the features.

3. The method as described in claim 2, wherein, Before performing at least one of chemical vapor deposition or atomic layer deposition to deposit Mo for selective or conformal filling of the feature, the method further includes the step of depositing a nucleation layer on top of either the metal backing layer or the metal seed layer.

4. The method as described in claim 3 further includes the step of: performing physical vapor deposition to deposit additional Mo on top of the Mo deposited on top of either the metal liner layer or the metal seed layer, to selectively fill or conformally fill the feature without vacuum disruption, wherein the additional Mo is deposited to a thickness of approximately 2000 Å.

5. The method as described in claim 4, further comprising the step of performing chemical mechanical polishing on the additional Mo.

6. The method as claimed in claim 1, further comprising the step of performing a pre-cleaning process on the substrate prior to forming either the metal pad layer or the metal seed layer, wherein the pre-cleaning process uses at least one of hydrogen plasma or fluorine plasma, and wherein one of a capacitively coupled plasma source, an inductively coupled plasma source, or a remote plasma source is used to form either the hydrogen plasma or the fluorine plasma.

7. The method as claimed in claim 1, wherein the silicate layer comprises at least one of the following: silane (SiH4) and cobalt (Co), SiH4 and Mo, SiH4 and ruthenium (Ru), or SiH4 and W, without vacuum destruction.

8. The method as described in claim 7 further includes the step of: performing physical vapor deposition to deposit a metal capping layer on top of the silicate layer within the feature, the metal capping layer comprising at least one of Co, Mo, Ru, or W, wherein the metal capping layer has a thickness of about 30 Å to about 100 Å.

9. The method as described in claim 8 further includes the step of performing at least one of atomic layer deposition or chemical vapor deposition to deposit Mo on top of the metal capping layer within the feature without vacuum disruption.

10. The method as described in any one of claims 8 to 9, wherein one of the metal liner layer or the metal seed layer is deposited on the metal capping layer within the feature.

11. The method as described in any one of claims 1 to 4 or 6 to 9, wherein the deposition of Mo using at least one of chemical vapor deposition or atomic layer deposition is not performed by first exposing at least one of Mo or W to hydrogen to perform redox.

12. A non-transitory computer-readable storage medium having instructions stored thereon that, when executed by a processor, perform a method for processing a substrate, the method comprising the steps of: depositing a silica layer in a feature defined in a layer on a substrate; forming a metal liner layer or a metal seed layer on top of the silica layer in the feature using physical vapor deposition via deposition of at least one of molybdenum (Mo) or tungsten (W); and depositing Mo on top of the at least one of the metal liner layer or the metal seed layer using at least one of chemical vapor deposition or atomic layer deposition, without vacuum disruption.

13. The non-transitory computer-readable storage medium as described in claim 12, wherein the feature is one of a trench, a through hole, or a dual damascene structure, and wherein the Mo is deposited on top of one of the metal liner layer or the metal seed layer to selectively fill or conformally fill one of the features.

14. The non-transitory computer-readable storage medium as described in claim 13, wherein, Before performing at least one of chemical vapor deposition or atomic layer deposition to deposit Mo for selective or conformal filling of the feature, the method further includes the step of depositing a nucleation layer on top of either the metal backing layer or the metal seed layer.

15. The non-transitory computer-readable storage medium as described in claim 14 further includes the following steps: performing physical vapor deposition to deposit additional Mo on top of the Mo deposited on top of either the metal liner layer or the metal seed layer, to selectively fill or conformally fill one of the features without vacuum disruption, wherein the additional Mo is deposited to a thickness of approximately 2000 Å.

16. The non-transitory computer-readable storage medium as described in claim 15 further includes the step of performing chemical mechanical polishing on the additional Mo.

17. The non-transitory computer-readable storage medium as described in any one of claims 12 to 16, further comprising the step of: performing a pre-cleaning process on the substrate prior to forming the metal pad layer or the metal seed layer, wherein the pre-cleaning process uses at least one of hydrogen plasma or fluorine plasma, and wherein one of a capacitively coupled plasma source, an inductively coupled plasma source, or a remote plasma source is used to form the hydrogen plasma or fluorine plasma.

18. A non-transitory computer-readable storage medium as described in claim 12, wherein the silicate layer comprises at least one of the following: silane (SiH4) and cobalt (Co), SiH4 and Mo, SiH4 and ruthenium (Ru), or SiH4 and W, without vacuum disruption.

19. The non-transitory computer-readable storage medium as described in any one of claims 12 to 16 or 18 further includes the step of: performing physical vapor deposition to deposit a metal capping layer on top of the silica layer within the feature, the metal capping layer comprising at least one of Co, Mo, Ru, or W, wherein the metal capping layer has a thickness of about 30 Å to about 100 Å.

20. A method for processing a substrate, comprising the steps of: performing a pre-cleaning process on a substrate, the substrate including a layer having a feature defined therein; forming a metal liner layer or a metal seed layer within the feature using physical vapor deposition via deposition of at least one of molybdenum (Mo) or tungsten (W); depositing a nucleation layer on top of the metal liner layer or the metal seed layer without vacuum destruction; and depositing Mo on top of the metal liner layer or the metal seed layer using at least one of chemical vapor deposition or atomic layer deposition to selectively fill or conformally fill the feature without vacuum destruction.

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