Method for depositing tungsten in high aspect ratio structures and semiconductor substrates - Patents.com

Abstract

The present invention discloses a method and a semiconductor substrate for depositing tungsten on a high aspect ratio structure, the high aspect ratio structure being a recessed structure with an aspect ratio of greater than 50, the method includes a first deposition step of depositing a tungsten material layer of a first thickness on the sidewall and bottom of the recessed structure, a processing step of flowing a processing gas containing fluorine / chlorine-containing radicals and radicals containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen on the surface of the substrate, and a second deposition step of depositing a tungsten material layer of a second thickness so as to fill at least a part of the area of ​​the recessed structure with tungsten. The advantage is that the radicals in the processing gas form surface bonds on the surface of the tungsten material layer to slow down the subsequent deposition of tungsten material at that location, and the etching of the fluorine / chlorine-containing radicals further avoids the premature closing of the top opening of the recessed structure, and moves and shrinks the slits in the recessed structure downward, avoiding the slits being exposed in the subsequent CMP processing process, which helps to improve the service life and electrical performance of the substrate.

Description

[Technical field]

[0001] The present invention relates to the field of semiconductors, and in particular to a method for depositing tungsten on high aspect ratio structures and semiconductor substrates. [Background technology]

[0002] In memory devices, tungsten is mainly applied to the word lines and contacts of 3D NAND. 3D NAND is formed of multiple stack layers, and with the increase in device integration, the number of stack layers of 3D NAND also increases, and the size of the feature areas as word lines and contacts is reduced. Currently, 128 stack layers are mainstream in 3D NAND, and accordingly, the feature areas have a very high aspect ratio, and the reduction in the size of the feature areas brings great challenges to the process and equipment of tungsten deposition.

[0003] In the conventional tungsten deposition process, when a general tungsten deposition process is performed on a feature region with a high aspect ratio (>50:1), a layer of tungsten material is usually deposited on the feature region as a seed crystal or nucleation layer, and then multiple tungsten filling layers are sequentially deposited on the feature region. However, with the feature size shrinking and the number of stacked layers increasing in the feature region structure, it is difficult to ensure the filling effect of the feature region by the conventional solution, and there are still large slits inside the feature region. In the subsequent chemical mechanical polishing (CMP) process, a part of the top of the feature region in the thickness direction is polished and removed, and the slits inside the feature region are exposed during the CMP process if they are too high, and the CMP slurry enters the slits to erode the tungsten filling layer, resulting in the loss of tungsten filling material, which reduces the electrical performance and service life of the entire device, and further causes the increase of the loss of the entire device. Summary of the Invention

[0004] The object of the present invention is to provide a method for depositing tungsten in high aspect ratio structures and a semiconductor substrate, which is for depositing tungsten material in a recessed structure with an aspect ratio of greater than 50, and combines a first deposition step, a treatment step and a second deposition step to treat a tungsten material layer with a treatment gas, etch the surface of the tungsten material layer with radicals containing fluorine / chlorine in the treatment gas to increase the top opening of the recessed structure, which is conducive to the subsequent filling of tungsten material, and form surface bonds on the surface of the tungsten material layer with radicals containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen in the treatment gas to slow down the subsequent deposition of tungsten material at the position of the surface bonds, further avoid premature closing of the top opening of the recessed structure, move down and shrink the slits in the recessed structure, which is conducive to the improvement of the service life and electrical performance of the semiconductor substrate. However, the method does not form an observable new thin layer on the tungsten material layer and does not adversely affect the semiconductor substrate.

[0005] In order to achieve the above object, the present invention is realized by the following technical means.

[0006] 1. A method of depositing tungsten into a high aspect ratio structure, the high aspect ratio structure being a recessed structure recessed downwardly from a surface of a substrate and having an aspect ratio of greater than 50:1, the method comprising: a first deposition step of depositing a layer of tungsten material on the sidewalls and bottom of the recessed structure to a first thickness of 10-500 angstroms; A process step of flowing a process gas containing radicals containing fluorine / chlorine and radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, and oxygen at a flow rate range of 1 to 200 sccm onto the surface of the substrate, and forming a tungsten growth inhibition region by the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, and oxygen and at least a partial region of the tungsten material layer deposited on the sidewall of the recessed structure; and a second deposition step of depositing a layer of tungsten material of a second thickness within the recessed structure treated in the treatment step so as to fill at least a portion of the recessed structure with tungsten.

[0007] Optionally, the tungsten growth inhibition region includes a region extending from a surface of the substrate along a sidewall of the recess structure toward a bottom of the recess structure a first depth that is less than or equal to two-thirds the depth of the recess structure.

[0008] Optionally, the process gas etches the tungsten material layer on the top sidewall of the recessed structure to a second depth, the second depth being less than or equal to the first depth, with fluorine / chlorine containing radicals.

[0009] Optionally, the time range of the processing step is 0 to 180 s.

[0010] Optionally, the time range of the treatment step is 0 to 40 s.

[0011] Optionally, the interior of the tungsten material layer filled in the second deposition step has elongated gaps whose height is less than 60% of the depth of the recessed structures.

[0012] Optionally, the first deposition step is performed using an atomic layer deposition-like process or a pulsed deposition process or a combination of an atomic layer deposition-like process / pulsed deposition process and a chemical vapor deposition process; The second deposition step is carried out using a chemical vapor deposition process.

[0013] Optionally, the first deposition step deposits a tungsten nucleation layer or a tungsten nucleation layer and a portion of a tungsten bulk layer.

[0014] Optionally, the method further comprises repeatedly performing the treating step and the second depositing step to fill a greater portion of the recessed structure.

[0015] Optionally, the flow rate or the processing time of the process gas in the current processing step is less than the flow rate or the processing time of the process gas in the previous processing step.

[0016] Optionally, the process time of the current second deposition step is less than the process time of the previous second deposition step.

[0017] Optionally, the process time of the last said second deposition step is greater than the process time of the previous second deposition step.

[0018] Optionally, when the treatment step and the second deposition step are repeatedly performed, the method further includes performing the first deposition step after at least one second deposition step.

[0019] Optionally, the treatment step includes a plurality of alternating treatment and cleaning sub-steps, the treatment sub-steps including flowing a treatment gas and the cleaning sub-steps including flowing an inert gas.

[0020] Optionally, the process time of the treatment sub-step or the purification sub-step is less than 60 s.

[0021] Optionally, the process time of the treatment sub-step or the purification sub-step is less than 10 s.

[0022] Optionally, the process gas is selected from one of SF6, NF3, HCl, fluorocarbon compounds, fluorohydrocarbon compounds, fluorooxygen compounds, chlorocarbon compounds, chlorinated hydrocarbon compounds, chlorinated oxygen compounds, or mixtures thereof.

[0023] Optionally, the processing step includes multiple processing operations, and the processing effect of each processing operation is adjustable.

[0024] Optionally, the process conditions for each treatment operation are the same; Alternatively, the treatment time of each treatment operation may be decreased in a stepwise manner and / or the pressure of each treatment operation may be increased in a stepwise manner and / or the gas flow rate may be decreased in a stepwise manner.

[0025] Optionally, the pressure range of the first deposition step is 1 to 30 Torr, and the pressure range of the second deposition step is 5 to 100 Torr.

[0026] Optionally, a method of depositing tungsten into a high aspect ratio structure, the high aspect ratio structure being a recessed structure recessed downwardly from a surface of a substrate and having an aspect ratio of greater than 50:1, the method of depositing tungsten comprising: a first deposition step of depositing a tungsten nucleation layer on the sidewalls and bottom of the recessed structure; A process step of flowing a process gas containing radicals containing fluorine / chlorine and radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, and oxygen at a flow rate range of 1 to 200 sccm onto the surface of the substrate, and forming a tungsten growth suppression region by the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, and oxygen and at least a part of the region of the tungsten nucleation layer deposited on the side wall of the recessed structure; and a second deposition step of depositing a layer of tungsten material within the recessed structure treated in the treatment step so as to fill at least a portion of the recessed structure with tungsten.

[0027] Optionally, the first deposition step is performed using an atomic layer deposition-like process and / or a pulsed deposition process, and the second deposition step is performed using a chemical vapor deposition process.

[0028] Optionally, the tungsten nucleation layer deposited in the first deposition step has a thickness of less than 150 Angstroms.

[0029] Optionally, the treatment step includes a plurality of alternating treatment and cleaning sub-steps, the treatment sub-steps including flowing a treatment gas and the cleaning sub-steps including flowing an inert gas.

[0030] Optionally, the time range of the treatment step is 0 to 30 s.

[0031] Optionally, the process gas is selected from one of SF6, NF3, HCl, fluorocarbon compounds, fluorohydrocarbon compounds, fluorooxygen compounds, chlorocarbon compounds, chlorinated hydrocarbon compounds, chlorinated oxygen compounds, or mixtures thereof.

[0032] Optionally, the method further comprises repeatedly performing the treating step and the second depositing step to fill a greater portion of the recessed structure.

[0033] Optionally, the flow rate or process time of the process gas in the current process step is smaller than the flow rate or process time of the process gas in the previous process step, and / or the process time of the current second deposition step is smaller than the process time of the previous second deposition step.

[0034] Optionally, the process time of the last said second deposition step is greater than the process time of the previous second deposition step.

[0035] Optionally, when the treatment step and the second deposition step are repeatedly performed, the method further includes performing the first deposition step after at least one second deposition step.

[0036] Optionally, a semiconductor substrate including a layer of material on a surface thereof, A recessed structure having an aspect ratio greater than 50 is formed in the material layer, the recessed structure having a barrier layer on a sidewall and a bottom wall, an internal space of the recessed structure surrounded by the barrier layer is filled from bottom to top with a tungsten material layer to form a low resistance path from the bottom of the recessed structure to the top of the recessed structure, and the tungsten material layer is manufactured by a method of depositing tungsten in a high aspect ratio structure.

[0037] Optionally, the tungsten material layer has a plurality of gaps separated from each other and distributed vertically, and the height of each of the gaps is less than 1 / 4 of the height of the recessed structure.

[0038] Optionally, a semiconductor substrate includes a material layer on a surface thereof, in which a recess structure having an aspect ratio greater than 50 is formed, the recess structure has a barrier layer on a sidewall and a bottom wall, an inner space of the recess structure surrounded by the barrier layer is filled with a tungsten material layer from bottom to top, forming a low resistance path from the bottom of the recess structure to the top of the recess structure, and an inside of the tungsten material layer includes a plurality of gaps separated from each other and distributed vertically, and a height of each of the gaps is less than 1 / 4 of a height of the recess structure.

[0039] The present invention has the following advantages over the prior art:

[0040] The method of depositing tungsten in a high aspect ratio structure and a semiconductor substrate of the present invention deposits a tungsten material in a recessed structure having an aspect ratio of greater than 50, the method combines a first deposition step, a treatment step and a second deposition step, and in the treatment step, a treatment gas is used to treat the tungsten material layer formed in the first deposition step, and the fluorine / chlorine-containing radicals in the treatment gas etch the surface of the tungsten material layer to increase the top opening of the recessed structure and facilitate the subsequent filling of the tungsten material, and the radicals in the treatment gas containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen form surface bonds on the surface of the tungsten material layer adjacent to the opening of the recessed structure, and the region where the surface bonds are formed retards the growth of the tungsten material layer in the second deposition step and forms a tungsten growth inhibition region on the sidewall of the recessed structure, and the flow rate of the treatment gas in the treatment step is controlled to a range of 1 to 200 sccm to control the depth of the active radicals entering the recessed structure and further control the depth of the tungsten growth inhibition region. It further avoids premature closure of the top opening of the recessed structure, moves the slits in the recessed structure downward and shrinks them, and avoids the slits from being exposed in the subsequent CMP processing process, which helps to improve the service life and electrical performance of the semiconductor substrate, and further minimizes power loss and overheating in integrated circuit designs. Meanwhile, the method does not form an observable new thin layer on the tungsten material layer and does not adversely affect the semiconductor substrate.

[0041] Furthermore, the processing steps of the method can act on the tungsten nucleation layer such that the subsequent tungsten bulk layer tends to deposit in the middle and lower parts of the internal space of the recessed structure, further ensuring that the slits in the recessed structure are moved downward and reduced.

[0042] Furthermore, the method uses a multiple-step repeated manner to gradually fill and grow tungsten in the recessed structure, divides the large slit in the recessed structure into multiple small slits, and moves the position of the slit in the recessed structure further downward, so as to avoid the slit being exposed in the subsequent CMP processing process and to avoid the erosion of the tungsten material layer in the recessed structure. [Brief description of the drawings]

[0043] [Figure 1] 1 is a schematic diagram of a portion of a semiconductor substrate of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of a method for depositing tungsten on a high aspect ratio structure of the present invention. [Diagram 3] FIG. 1 is a schematic diagram of a tungsten deposition process using a single processing step according to the present invention. [Figure 4] FIG. 1 is a schematic diagram of a tungsten deposition process using a single processing step in another embodiment. [Diagram 5] FIG. 1 is a schematic diagram of a tungsten deposition process using multiple processing steps according to the present invention. [Figure 6] FIG. 1 is a schematic diagram of a tungsten deposition process using multiple processing steps according to the present invention. [Figure 7] FIG. 10 is a schematic diagram of a method for depositing tungsten on a high aspect ratio structure according to yet another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] In order to make the purpose, technical means and advantages of the embodiments of the present invention clearer, the technical means in the embodiments of the present invention will be described clearly and completely below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, and are not all of the embodiments. All other embodiments obtained based on the embodiments of the present invention without the creative efforts of those skilled in the art are all within the scope of protection of the present invention.

[0045] It should be noted that, in this specification, the terms "comprises," "including," "having," or any other variant thereof, are intended to cover a non-exclusive "comprise," whereby a process, method, article, or device that includes a set of elements not only includes those elements, but also includes other elements not expressly listed or that are inherent in such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "including" or "including" does not exclude that other elements are also present in the process, method, article, or device that includes the element.

[0046] It should be noted that the drawings are all very simplified and not to scale, and are merely intended to facilitate, clarify and assist in explaining the embodiments of the present invention.

[0047] FIG. 1 is a schematic diagram of a portion of a semiconductor substrate 100 of the present invention. As shown in FIG. 1, the semiconductor substrate 100 includes a material layer 101 (e.g., silicon oxide) on a surface thereof, in which a plurality of recessed structures 102, i.e., feature regions, having an aspect ratio greater than 50 are formed, and the recessed structures 102 may be hole-like structures or groove-like structures, and have a barrier layer 103 on the sidewall and bottom wall, e.g., a titanium nitride (TiN) layer. The inner space surrounded by the barrier layer 103 needs to be filled with a tungsten material layer from bottom to top, so as to form a low resistance path from the bottom of the recessed structures 102 to the top of the recessed structures 102. However, as technology nodes increase day by day, the requirements for the deposition process of the tungsten material layer in the high aspect ratio recessed structures 102 also increase.

[0048] In the tungsten deposition process, more tungsten material is deposited near the top opening of the recessed structure 102 during deposition compared with the bottom in the recessed structure 102, forming an overhang at the top opening. With the progress of the deposition process, the overhang gradually grows, and further the top opening of the recessed structure 102 is closed early, and there is a large slit inside the recessed structure 102. Therefore, in order to ensure the deposition effect of the tungsten material layer, a conformal inhibition treatment process can be performed to perform an inhibition operation on the recessed structure 102 to prevent the top opening region of the recessed structure 102 from being pinched off in the subsequent deposition process. However, the conformal inhibition treatment process introduces a certain thickness of high resistance layer, which can be recognized and detected, and thus has a great impact on the conductivity of the tungsten material layer, and the semiconductor substrate 100 cannot form a low resistance passage, which further increases the loss of the device.

[0049] In order to ensure good electrical performance and service life of the semiconductor substrate 100, the present invention provides a method for depositing tungsten into a high aspect ratio structure, which is a recessed structure 102 that is recessed downward from the surface of the substrate and has an aspect ratio greater than 50:1. The method of the present invention is also effective for a recessed structure having an aspect ratio less than 50:1. Since undesired slits 205 or holes are likely to appear inside the recessed structure 102 having an aspect ratio greater than 50:1 during tungsten deposition, the present invention is described by taking the aspect ratio of the recessed structure 102 as an example, which is greater than 50:1.

[0050] As shown in FIGS. 2 to 7, the method for depositing tungsten in a high aspect ratio structure of the present invention includes a first deposition step of depositing a tungsten material layer of a first thickness, which is 10 to 500 angstroms, on the sidewall and bottom of a recessed structure 102; a treatment step (Treatment) of flowing a treatment gas containing radicals containing fluorine or chlorine and radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, and oxygen, and having a flow rate of 1 to 200 sccm, onto the surface of the substrate, forming a tungsten growth inhibition region 201 by the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, and oxygen and at least a portion of the tungsten material layer deposited on the sidewall of the recessed structure 102; and a second deposition step of depositing a tungsten material layer of a second thickness in the recessed structure 102 treated in the treatment step, so as to fill at least a portion of the recessed structure 102 with tungsten.

[0051] As can be seen from the above, the method of depositing tungsten in a high aspect ratio structure of the present invention includes depositing a tungsten material layer in the recessed structure 102 (barrier layer 103), then flowing a processing gas to process the surface of the tungsten material layer, etching the tungsten material layer in the top opening region of the recessed structure 102 with radicals containing fluorine / chlorine in the processing gas to increase the size of the top opening region and prevent early closure of the inside of the recessed structure 102 in a subsequent process, and then etch the tungsten material layer with radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen in the processing gas to form a tungsten layer. The surface bond is formed on the surface of the tungsten material layer, and the area where the surface bond is formed retards the growth of the tungsten material layer in the second deposition step, forming a tungsten material layer deposition retardation area, i.e., a tungsten growth inhibition area 201 (the dot area on the sidewall of the recessed structure 102 in FIG. 3) on the sidewall of the recessed structure 102, and by controlling the flow range of the processing gas and the flow time of the processing gas in the processing step, the depth to which the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen enter the recessed structure 102 can be controlled, and the depth of the tungsten growth inhibition area 201 can be controlled. The presence of the surface bond retards / inhibits the deposition of the subsequent tungsten material layer at that position, but does not form an observable new thin film and does not affect the electrical performance of the semiconductor substrate 100. The flow rate range of the process gas of the present invention is 1-200 sccm, and when the internal pressure of the chamber does not change and the flow rates of other inert gases inside the chamber do not change, the flow rate of the process gas can be controlled to control the concentration of the process gas at the top of the recessed structure 102 and further control the diffusion rate of the process gas inside the recessed structure 102. Since the flow rate of the process gas in the process step of the present invention is low and the flow time is short, for example, 0-180 seconds, the depth to which radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen diffuse into the recessed structure 102 is limited, and a tungsten growth suppression region 201 is formed only on the sidewall at a certain distance below the opening of the recessed structure 102.By controlling the flow rate and time of the process gas, the deposition of the tungsten material layer in the top opening region of the recessed structure 102 and in the sidewall region adjacent to the top opening of the recessed structure 102 by a certain depth is delayed in the second deposition step, and in the subsequent second deposition step, the tungsten material layer is preferentially deposited in the middle and lower part of the recessed structure 102 other than the tungsten growth inhibition region 201, delaying the closure of the opening of the recessed structure 102, reducing the height of the slit 205 in the recessed structure 102 and moving the position of the slit 205 downward (to the middle and lower part of the recessed structure 102), thereby reducing the risk of the slit 205 being prematurely exposed and attacked by slurry in the CMP process, improving the service life of the semiconductor substrate 100, and ensuring a good low-resistance passage.

[0052] 3, the tungsten growth suppression region 201 includes a region that extends a first depth from the surface of the semiconductor substrate 100 along the sidewall of the recess structure 102 toward the bottom of the recess structure 102, and at least a portion of the region at the top surface of the semiconductor substrate 100. Optionally, the first depth is less than or equal to two-thirds of the depth of the recess structure 102.

[0053] Due to the steric hindrance effect of gas diffusion and the properties of the radicals themselves, various radicals in the processing gas are difficult to enter the small-sized recessed structure 102, and the etching effect of the radicals containing fluorine / chlorine and the density of the surface bonds formed in the first thickness of the tungsten material layer by the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen gradually weaken downward from the top of the recessed structure 102, so that the effect of the processing gas in the above processing step is most significant on the tungsten material layer in the top region of the recessed structure 102. Since the tungsten deposition inhibition effect of the surface bonds on the tungsten material layer in the top region is most significant, in the subsequent tungsten deposition process, the tungsten deposition in the top region is most significantly delayed, so that the tungsten material is preferentially deposited in the bottom region in the recessed structure 102.

[0054] In practical application, the component diffusion can be controlled according to the difference of each component in the processing gas as required, for example, the component content of radicals containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen in the processing gas is increased so that the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen passivate the tungsten material layer at the first depth of the sidewall of the recessed structure 102, and the processing gas etches the tungsten material layer at the second depth of the sidewall of the top of the recessed structure 102 with radicals containing fluorine / chlorine, and the subsequent tungsten is preferentially deposited in the middle and lower parts of the recessed structure 102, and the slit 205 in the recessed structure 102 is further reduced and moved downward, so that the second depth is smaller than the first depth, i.e., the range of the tungsten growth inhibition region 201 is larger than the range of the etching region. Of course, each gas component in the processing gas can be adjusted so that the second depth is equal to the first depth.

[0055] As shown in FIG. 3, in this embodiment, the tungsten material layer of a first thickness deposited in the first deposition step is a tungsten nucleation layer 202, and the tungsten material layer of a second thickness deposited in the second deposition step is a tungsten bulk layer 203. The tungsten nucleation layer 202 deposited in the first deposition step is etched by the process gas, and the etched thickness is smaller than the first thickness of the tungsten nucleation layer 202 of the layer, and a tungsten growth inhibition region 201 is formed on the surface of the tungsten nucleation layer 202 on the top of the recessed structure 102, which can inhibit the subsequent deposition of the tungsten bulk layer 203 on the top of the recessed structure 102 and prematurely close the opening of the recessed structure 102 to avoid pinching off the deposition path of the tungsten material in the recessed structure 102, and no observable new thin film is formed in the tungsten growth inhibition region 201, which has a small impact on the electrical performance in the recessed structure 102, and is helpful to ensure the good performance of the semiconductor device.

[0056] Optionally, the first deposition step is performed using an atomic layer deposition-like process and / or a pulsed deposition process and the second deposition step is performed using a chemical vapor deposition (CVD) process, i.e., different deposition processes are used for the tungsten nucleation layer 202 and the tungsten bulk layer 203, and optionally both can be performed in the same chamber.

[0057] Specifically, the atomic layer deposition-like process involves sequentially flowing one or more reducing agents, a purge gas, a tungsten-containing precursor, and a purge gas into the chamber, and then cyclically repeating the process until a desired thickness is obtained, and then forming a tungsten nucleation layer 202, i.e., a thin conformal nucleation layer to be subsequently deposited, by an atomic layer deposition-like process. The tungsten nucleation layer 202 thus formed has high density and low surface roughness, which contributes to the surface flatness of the subsequently deposited tungsten material layer, and further forms a low resistivity tungsten film 204. The pulsed deposition process involves simultaneously flowing one or more reducing agents and a tungsten-containing precursor into the chamber, and then flowing a purge gas, and then cyclically repeating the process until a desired thickness of the tungsten nucleation layer 202 is obtained.

[0058] It should be noted that the ALD process and the pulse deposition process are not limited to the above, and the above process steps can be adjusted according to the actual process conditions or application needs, and the present invention is not limited thereto. Exemplarily, the ALD process of an embodiment includes a step S1 of flowing B2H6 / SiH4 (reducing agent 1) + H2 (reducing agent 2), a step S2 of flowing an inert gas to purge, a step S3 of flowing a tungsten-containing precursor + H2 (reducing agent 2), a step S4 of flowing an inert gas to purge, and a step of repeatedly performing steps S1 to S4. In this embodiment, the reducing agent 2 has a weaker reaction activity with the tungsten-containing precursor than the reducing agent 1 and the tungsten-containing precursor, which increases the diffusion time of the tungsten-containing precursor, and therefore the distribution of the tungsten-containing precursor above the semiconductor substrate 100 becomes more uniform. Optionally, the actual deposition rate of the atomic layer deposition-like process is adjusted to be higher than that of the general atomic layer deposition process so as to improve the deposition rate of the tungsten nucleation layer 202. In practical applications, a suitable deposition process can be selected in the first deposition step according to process requirements and equipment conditions so as to form a tungsten nucleation layer 202 that meets practical needs.

[0059] Optionally, the process pressure range of the first deposition step is 1-30 Torr, the process temperature range is 300-400° C., and the thickness of the tungsten nucleation layer 202 is less than 150 Å. For the deposition of tungsten material in a high aspect ratio structure, too thick material should not be deposited in the initial stage. Otherwise, it is equivalent to reducing the size of the opening at the top of the recessed structure 102, which affects the gas diffusion during the subsequent deposition and affects the filling effect of the recessed structure 102. If the tungsten nucleation layer 202 is deposited using an atomic layer deposition-like process, the time for one cycle is long and the response to switching the deposition rate is slow, and the thickness of the tungsten nucleation layer 202 deposited in the initial stage directly affects the filling rate of the tungsten material in the entire recessed structure 102, and further affects the throughput of the semiconductor substrate 100 by the processing device, so the film thickness formed by depositing the tungsten material in the initial stage is extremely important. In this embodiment, the tungsten nucleation layer 202 formed in the first deposition step is approximately 100 Angstroms.

[0060] After the first deposition step is completed, the processing gas is flowed and the processing gas is dissociated by a remote plasma device to process the surface of the tungsten nucleation layer 202. In the processing step, the tungsten nucleation layer 202 is etched by the radicals containing fluorine / chlorine in the processing gas, and its etching thickness is < the thickness of the previous tungsten nucleation layer 202; meanwhile, the tungsten bulk layer 203 cannot be directly deposited on the barrier layer 103 of the semiconductor substrate 100, and the tungsten nucleation layer 202 needs to be deposited before that, and there are some dangling bonds on the surface of the tungsten nucleation layer 202, and these dangling bonds can generally make the tungsten bulk layer 203 adhere well to the tungsten nucleation layer 202, so as to grow the subsequent tungsten material. In the process step of the present invention, radicals in the process gas containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen bond with the dangling bonds of the tungsten growth inhibition region 201 on the surface of the tungsten nucleation layer 202 to form surface bonds, so that the tungsten bulk layer 203 cannot bond with the dangling bonds of the tungsten nucleation layer 202 in that region, thereby delaying the subsequent deposition of the tungsten bulk layer 203 at that location. If it is necessary to continue the growth of tungsten material in the tungsten growth inhibition region 201, the dangling bonds need to be reformed at this location. For example, when the tungsten bulk layer 203 is deposited using a chemical vapor deposition process in the subsequent second deposition step, the reformation of the dangling bonds at this location requires a certain reaction time for the subsequent deposition of the tungsten bulk layer 203. Within this reaction time, the tungsten bulk layer 203 can be normally deposited in areas other than the tungsten growth inhibition region 201. In terms of the deposition of tungsten material in the entire recessed structure 102, the processing gas will cause a tungsten growth delay of tens of seconds or even thousands of seconds in the tungsten growth inhibition region 201 (the delay time is determined by the processing strength of the processing gas and the specific process of the subsequent deposition of tungsten material).

[0061] Optionally, the flow rate of the processing gas in the processing step is in the range of 1-200sccm, the process pressure is in the range of 1-30Torr, the process temperature is in the range of 300-400°C, and the process time is in the range of 0-40s. It should be noted that the present invention does not limit the above parameters, and the above parameters can be controlled according to the actual needs to achieve the optimal processing effect, for example, in another embodiment, the time range of the processing step is 0-30s to adjust the processing intensity of the processing gas. Further optionally, the processing gas includes, but is not limited to, one of SF6, NF3, HCl, fluorocarbon compounds (such as CF4, CHF3, C2F4), fluorohydrocarbon compounds, fluorooxygen compounds, chlorocarbon compounds, chlorinated hydrocarbon compounds, chlorinated oxygen compounds, or mixtures thereof, i.e., the processing gas is a gas or gasified precursor containing at least one of fluorine / chlorine and carbon, sulfur, nitrogen, hydrogen, or oxygen.

[0062] After the processing step is completed, a second deposition step is performed. In this embodiment, a tungsten bulk layer 203 is deposited using a chemical vapor deposition process. One or more reducing agents and tungsten-containing precursors are simultaneously flowed into the chamber, and the reducing agent and tungsten-containing precursor deposit a second thickness of a tungsten bulk layer 203 on the tungsten nucleation layer 202 treated by the processing gas using a chemical vapor deposition process. The processing step includes radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen in the processing gas, forming a tungsten growth inhibition region 201 on the surface of the sidewall at a certain depth below the top opening of the recessed structure 102, and the tungsten material in the second deposition step is preferentially deposited on the surface of the tungsten nucleation layer 202 in the middle and lower parts of the recessed structure 102, and further moving and shrinking the slits 205 in the recessed structure 102 downward. Alternatively, tungsten hexafluoride (WF6) is used as the tungsten-containing precursor, and hydrogen (H2) is used as the reducing agent. Of course, the types of tungsten-containing precursor and reducing agent are not limited to the above, and other reagents may be used as long as they achieve the same deposition effect. For example, tungsten-containing precursor is WC 16As a reducing agent, silane, diborane, etc. are used. Optionally, the pressure range of the second deposition step is 5-100 Torr, and the process temperature range is 300-400°C.

[0063] After the second deposition step is completed, the inside of the tungsten material layer filled in the second deposition step has an elongated gap whose height is less than 60% of the depth of the recessed structure 102, that is, the tungsten material layer fills the bottom of the recessed structure 102. The present invention, by setting a treatment step between the first deposition step and the second deposition step, etches the tungsten material layer in the opening with the radicals containing fluorine / chlorine in the treatment gas after depositing a thin tungsten material layer in the first deposition step, and forms a tungsten growth inhibition region 201 on the surface of the tungsten material layer deposited on the sidewall adjacent to the opening of the recessed structure 102 with the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen in the treatment gas, thereby delaying the growth of the tungsten material layer in the region adjacent to the opening of the recessed structure 102, and ensuring that more deposition gas enters the bottom of the high aspect ratio recessed structure 102 in the second deposition step to grow the tungsten material layer. Although it cannot ensure complete removal of the elongated gap inside the tungsten material layer, the length of the elongated gap in the recess structure 102 can be shortened, and by slowing down the closing of the opening of the recess structure 102, the upper end of the formed elongated gap is as close as possible to the bottom of the recess structure 102, which further avoids the exposure of the elongated gap when performing a chemical mechanical grinding (CMP) process on the surface of the semiconductor substrate 100, thereby improving the performance of the semiconductor substrate 100.

[0064] Of course, the types of each tungsten material layer are not limited to the above, and may be other configurations. For example, in another embodiment, as shown in FIG. 4, the tungsten material layer deposited in the first deposition step is a tungsten nucleation layer and a part of a tungsten bulk layer (which may be called a tungsten film 204), that is, a layer of tungsten film 204 is formed first, and the tungsten bulk layer of the tungsten film 204 is subjected to a treatment step to form a tungsten growth inhibition region 201 to realize a surface treatment operation and avoid premature pinching off of the subsequent tungsten deposition path. After the surface treatment is performed on the tungsten film 204, the subsequent tungsten material layer is continued to be deposited, so that a small slit 205 is formed inside the recessed structure 102, and the erosion of the tungsten material due to the exposure of the slit 205 during the subsequent CMP process is avoided. Optionally, in the first deposition step of this embodiment, the tungsten film 204 may be deposited using an atomic layer deposition-like process or a pulsed deposition process or a combination of an atomic layer deposition-like process / pulsed deposition process and a chemical vapor deposition process, and the specific steps of the various processes can be referred to the above description, and the description will be omitted here.Moreover, optionally, in this embodiment, the thickness range of the tungsten film 204 deposited in the first deposition step is 10-500 angstroms, the temperature range of the deposition process of the tungsten nucleation layer 202 is 300-400°C, the process pressure range is 5-100 Torr, and in this embodiment, the etching thickness of the process gas in the process step is smaller than the thickness of the previous layer tungsten film 204.

[0065] In practical application, the present invention does not limit the number of processing steps in the tungsten deposition process. In the embodiment shown in Figure 3, during tungsten deposition, only one processing step is performed, and then a second deposition step is performed to completely fill the recessed structure 102.

[0066] Of course, during the tungsten deposition, the process step may be performed multiple times, for example, the process step is performed twice. As shown in FIG. 5 and FIG. 6, the method of depositing tungsten on a high aspect ratio structure of the present invention further includes repeatedly performing the process step and the second deposition step to fill more parts of the recessed structure 102. Optionally, the etching thickness of each process step is smaller than the thickness of the remaining tungsten nucleation layer 202 and / or the thickness of the tungsten bulk layer 203. Using multiple process steps can realize a continuous processing of the tungsten material layer in the top region of the recessed structure 102, and in the tungsten deposition step after the process step, the large slit 205 in the recessed structure 102 is divided into a plurality of small slits 205, and the tungsten material always tends to be deposited in the middle and lower parts of the recessed structure 102 without being deposited in the top region of the recessed structure 102, and further ensures that the slits 205 in the recessed structure 102 are moved downward and reduced, and the control precision of the distribution of the slits 205 is improved. Optionally, the process time of the current second deposition step is smaller than that of the previous second deposition step, i.e., the gradual growth intensity of the tungsten material layer is gradually decreased to reduce the slits 205 during deposition. Optionally, the process time of the current second deposition step can be larger than that of the previous second deposition step, since a situation occurs where the remaining structure is filled at once at the end.

[0067] As can be seen from the above, there are some dangling bonds on the surface of the tungsten nucleation layer 202, and these dangling bonds can better attach the tungsten bulk layer 203 to the surface of the tungsten nucleation layer 202 so as to grow the subsequent tungsten material. Therefore, in order to facilitate the deposition of the subsequent tungsten bulk layer 203, a layer of tungsten nucleation layer 202 may be further deposited after the processing step and the second deposition step (see FIG. 5 and FIG. 6). That is, when the processing step and the second deposition step are performed multiple times, the method further includes performing the first deposition step after at least one second deposition step, and depositing a layer of tungsten nucleation layer 202 before the processing step so that the subsequent tungsten bulk layer 203 can better attach in the recessed structure 102.

[0068] Of course, according to the actual process environment and product requirements, the above method can be repeated multiple times to fill, that is, a cycle of a first deposition step-treatment step-second deposition step is carried out to realize the stepwise growth of the tungsten material layer in the recessed structure 102. The first cycle grows a layer of tungsten film 204 on the bottom and sidewall of the recessed structure 102, the second cycle grows a layer of tungsten film 204 in the middle and lower parts of the recessed structure 102, and continues to grow a layer of tungsten film 204 on the top of the recessed structure 102 until the Nth cycle, dividing the large slit 205 in the recessed structure 102 into a number of small slits 205, and moving the position of the slit 205 further downward in the recessed structure 102, so as to avoid the slit 205 being exposed in the subsequent CMP treatment process and the tungsten material layer in the recessed structure 102 being eroded. It is expected that the more times the above method is repeated, the smaller the slits 205 within the tungsten material layer in the recessed structure 102 will be, and the less performance loss the device will experience.

[0069] Repeating the treatment step and the second deposition step multiple times solves the problem that it is difficult to achieve both top and bottom filling effects in one deposition step, and the larger the aspect ratio of the recessed structure 102, the more likely it is that the bottom is filled but there is a large hole or slit 205 at the top, or the top has a high filling effect but there is a slit 205 at the bottom. By performing the treatment multiple times, the filling effect at each depth in the recessed structure 102 can be achieved, and by optimizing the process of each repeated step, the slit 205 can be effectively reduced in the interior and controlled to occur at a position close to the bottom of the recessed structure 102.

[0070] Optionally, in the process of performing the treatment step multiple times, the treatment intensity in the treatment step is successively weakened (which can be achieved by increasing the process pressure and / or decreasing the treatment time and / or decreasing the flow rate of the treatment gas, etc.) to ensure that the slits 205 in the recess structure 102 are moved downward and reduced, and the influence of the treatment step on the tungsten deposition is reduced. Exemplarily, the process conditions of the first treatment step are 300° C., 5 torr, 10 sccm, 30 s, and the process conditions of the second treatment step are 300° C., 5 torr, 10 sccm, 15 s.

[0071] In practical application, the depth range of the tungsten growth suppression region 201 formed in the processing step extending to the sidewall of the recessed structure 102 affects the deposition position of the tungsten material in the subsequent second deposition step, so that the deposition position of the subsequent tungsten material can be controlled by controlling the depth range of the tungsten growth suppression region 201 in the processing step. In terms of gas diffusion, when the flow rate of the processing gas is small and the processing time is short, the processing gas does not diffuse to the middle and lower parts of the recessed structure 102, but preferentially diffuses to the top of the recessed structure 102 and the sidewalls close to the top position. When the flow rate of the processing gas is small and the processing time is short, the total amount of the processing gas is also small, and the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen in the processing gas may not be able to saturate the surface of the tungsten material layer deposited in the first deposition step, that is, the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen in the processing gas may not be able to bond with all the dangling bonds in the top region. In this case, the processing strength of the processing gas is weakened, which reduces the retardation effect of the tungsten growth inhibition region 201, for example, originally retarding the growth of the tungsten material layer by tens of seconds, but now reducing the retardation to make the tungsten material layer grow within 10 seconds, causing the phenomenon of early closure of the top opening of the recess structure 102.

[0072] Based on the above factors, as shown in Fig. 7, the treatment step of the present invention includes a plurality of treatment sub-steps and purification sub-steps that are alternately performed, in which the treatment sub-steps are performed by flowing a treatment gas to perform surface treatment, and the purification sub-steps are performed by flowing an inert gas to perform purification, and the purpose of purification is to timely remove the treatment gas flowed in the treatment sub-steps to avoid the treatment gas from entering the recessed structure 102 to a too large depth, and by controlling the treatment depth of each treatment sub-step and the number of times each sub-step is performed, the treatment strength of the top of the recessed structure 102 can be increased, thereby preventing the premature closure of the top opening of the recessed structure 102. Meanwhile, by adjusting each sub-step according to the actual characteristics of the recessed structure 102, a stepwise treatment of the sidewall of the top opening of the recessed structure 102 can be realized, that is, the treatment effect of different depth positions of the sidewall can be made different.

[0073] Optionally, the process time of the treatment sub-step or the cleaning sub-step is less than 60s. Of course, the action time of the two sub-steps is not limited to the above, and can be adjusted according to the actual process requirements, and the present invention is not limited thereto, for example, in another embodiment, the process time of the treatment sub-step or the cleaning sub-step is less than 10s. Further, optionally, Ar can be used as the inert gas. Of course, other gases that do not affect the reaction can be used.

[0074] In addition, the processing of the processing steps in the present invention can be realized by combining multiple processing operations, and the processing effect of each processing operation can be adjusted to achieve different degrees of processing effect. No tungsten material layer is deposited during each processing operation, and multiple processing operations are combined to realize one complete processing step, improving the processing effect on the surface of the previous tungsten material layer, but not increasing the processing depth of the tungsten material layer of the recessed structure 102. Meanwhile, by controlling each processing operation, the processing effect that changes with the stepwise change in depth on the surface of the previous tungsten material layer can be achieved, and the filling effect of the tungsten material can be further improved. Optionally, each processing operation includes one processing sub-step and one cleaning sub-step, so as to further optimize the action intensity of the processing gas and realize the precise control of its processing effect.

[0075] Optionally, the process conditions for each treatment run are the same, for example, the first treatment run has process conditions of 300° C., 5 torr, 10 sccm, 10 s, followed by Ar purge, the second treatment run has process conditions of 300° C., 5 torr, 10 sccm, 10 s, followed by Ar purge, ..., the Nth treatment run has process conditions of 300° C., 5 torr, 10 sccm, 10 s, followed by Ar purge. During multiple processing operations with the same process conditions, the diffusion area of ​​the processing gas in each processing operation is approximately the same, and the subsequent processing operations can further improve the processing effect of the previous processing operation, for example, when the total amount of the processing gas in the first processing operation is too small, and the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen are unsaturated, and all the dangling bonds on the surface of the tungsten material layer in the top region of the sidewall of the recessed structure 102 are not combined with the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen or oxygen, the processing gas in the subsequent processing operation can further combine with the remaining dangling bonds in the region to improve the processing effect in the region. And because the process conditions of each processing operation are the same, the action range and intensity of each processing operation are predictable, which helps to realize precise control of the surface processing effect of the tungsten material layer.

[0076] Of course, the process conditions of each treatment operation may be different, and the treatment effect of each treatment operation may be gradually weakened by adjusting one or more process parameters. Optionally, the treatment time of each treatment operation may be gradually decreased, for example, the process conditions of the first treatment operation are 300° C., 5 torr, 10 sccm, 15 s, followed by Ar purging, the process conditions of the second treatment operation are 300° C., 5 torr, 10 sccm, 5 s, followed by Ar purging, ..., the process conditions of the Nth treatment operation are 300° C., 5 torr, 10 sccm, 3 s, followed by Ar purging.

[0077] In another embodiment, the treatment effect may be adjusted by gradually increasing the pressure and / or gradually decreasing the gas flow rate of each treatment operation. With the increase in pressure or the decrease in gas flow rate, the treatment effect of each treatment operation gradually weakens. By adjusting the process conditions of each treatment operation, the etching and activation effect of the tungsten material layer by the treatment gas is continuously improved, and the gradually decreasing effect of each treatment operation does not increase the treatment intensity of the tungsten material layer throughout the entire treatment step.

[0078] It should be noted that the processing effect of each processing operation is not limited to the above-mentioned gradual decrease trend, and can be designed according to the actual product requirements, and the present invention is not limited thereto. For example, due to the steric hindrance effect of gas diffusion and the properties of the radicals of the processing gas itself, the surface etching effect of the tungsten material layer of the recessed structure 102 by the processing gas and the density of the formed surface bonds gradually weaken from the top of the recessed structure 102 downward, that is, the tungsten material layer on the sidewall of the recessed structure 102 is less affected by the processing gas with increasing depth. However, in some application scenarios, during the deposition of the subsequent tungsten material layer, the tungsten material layer is required to move the range of the tungsten growth inhibition region 201 of the tungsten material layer on the sidewall downward, so that the tungsten material layer preferentially grows in the middle and lower layers of the recessed structure 102 without adhering to the tungsten material layer on the sidewall, and further prevent the premature closure of the top opening of the recessed structure 102. According to the above application requirements, a first processing operation can be used to preliminarily etch the tungsten material layer of the recessed structure 102 to form a surface bond, and as can be seen from the above, the etching of the processing gas can increase the opening of the recessed structure 102, which provides a convenient condition for the subsequent processing gas to enter the interior of the recessed structure 102. During the subsequent processing operation, the flow rate of the processing gas can be selectively increased, and / or the processing pressure can be decreased, and / or the processing time can be increased to enlarge the depth to which the processing gas etches and activates the tungsten material layer on the sidewall of the recessed structure 102, and further move the range of the tungsten growth inhibition region 201 downward.

[0079] As can be seen from the above, when the method of depositing tungsten in a high aspect ratio structure is used to manufacture a tungsten material layer on the semiconductor substrate 100, the internal space of the recessed structure 102 can be filled with the tungsten material layer from the bottom to the top, and the position of the slits 205 in the internal space is low and the slits 205 are small, which is helpful in forming a low resistance path from the bottom of the recessed structure 102 to the top of the recessed structure 102.

[0080] Furthermore, in the semiconductor substrate 100, the tungsten material layer filled in the recess structure 102 has a plurality of slits 205 separated from each other in the center and distributed vertically, and the height of each of the slits 205 is less than 1 / 4 of the height of the recess structure 102.

[0081] In summary, the method of depositing tungsten in high aspect ratio structures and the semiconductor substrate 100 of the present invention deposits tungsten material in a recessed structure 102 with an aspect ratio greater than 50, the method combines a first deposition step, a treatment step and a second deposition step, in which the treatment step uses a treatment gas to treat the tungsten material layer formed in the first deposition step, and the fluorine / chlorine-containing radicals in the treatment gas etch the surface of the tungsten material layer to increase the top opening of the recessed structure 102, which can be useful for subsequent filling of the tungsten material; The radicals in the process gas containing at least one of carbon, sulfur, nitrogen, hydrogen, and oxygen form surface bonds on the surface of the tungsten material layer adjacent to the opening of the recessed structure 102, and the area where the surface bonds are formed retards the growth of the tungsten material layer in the second deposition step, and forms a tungsten growth suppression region 201 on the sidewall of the recessed structure 102. By controlling the flow rate range of the process gas in the process step to 1-200 sccm, the depth to which the active radicals enter the recessed structure 102 can be controlled, and the depth of the tungsten growth suppression region 201 can be further controlled. The premature closure of the top opening of the recessed structure 102 is further avoided, and the slits 205 in the recessed structure 102 are moved downward and reduced, and the slits 205 are prevented from being exposed in the subsequent CMP process, which is helpful in improving the service life and electrical performance of the semiconductor substrate 100. Meanwhile, the method does not form an observable new thin film layer on the tungsten material layer, and does not adversely affect the semiconductor substrate 100.

[0082] Furthermore, the processing steps of the method can act on the tungsten nucleation layer 202 so that a subsequent tungsten bulk layer 203 is deposited in the middle and lower parts of the internal space of the recess structure 102, further ensuring that the slits 205 in the recess structure 102 are moved downward and reduced in size.

[0083] Furthermore, the method uses a multiple-step repeated manner to gradually fill and grow tungsten in the recessed structure 102, divides the large slit 205 in the recessed structure 102 into multiple small slits 205, and moves the position of the slit 205 in the recessed structure 102 further downward, so as to avoid the slit 205 being exposed in the subsequent CMP processing process and to avoid the erosion of the tungsten material layer in the recessed structure 102.

[0084] Although the contents of the present invention have been described in detail by the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. After reading the above contents, multiple modifications and alternatives of the present invention will be obvious to those skilled in the art. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. 1. A method for depositing tungsten in high aspect ratio structures, comprising: The high aspect ratio structure is a recessed structure recessed downwardly from a surface of a substrate and having an aspect ratio of greater than 50:1, and the method of depositing tungsten comprises: a first deposition step of depositing a layer of tungsten material on the sidewalls and bottom of the recessed structure to a first thickness, the first thickness being between 10 and 500 angstroms; A process step of flowing a process gas containing fluorine / chlorine radicals and radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen at a flow rate range of 1 to 200 sccm onto the surface of the substrate, forming a tungsten growth inhibition region by the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen and at least a portion of a region of a tungsten material layer deposited on a sidewall of the recessed structure; and a second deposition step of depositing a layer of tungsten material of a second thickness within the recessed structure treated in the treatment step so as to fill at least a portion of the recessed structure with tungsten.

2. 2. The method of depositing tungsten in high aspect ratio structures of claim 1, wherein the tungsten growth inhibition region includes a region extending from a surface of the substrate along a sidewall of the recessed structure toward a bottom of the recessed structure a first depth that is less than or equal to two-thirds of a depth of the recessed structure.

3. 3. The method of claim 2, wherein the process gas etches the tungsten material layer at the top sidewall of the recessed structure at a second depth, the second depth being less than or equal to the first depth, with fluorine / chlorine containing radicals.

4. 2. The method of depositing tungsten on high aspect ratio structures of claim 1, wherein the processing step has a time range of 0 to 180 s.

5. 2. The method of depositing tungsten on high aspect ratio structures of claim 1, wherein the processing step has a time range of 0-40 s.

6. 2. The method of depositing tungsten in a high aspect ratio structure according to claim 1, wherein the inside of the tungsten material layer filled in the second deposition step has an elongated gap whose height is less than 60% of the depth of the recessed structure.

7. performing the first deposition step using an atomic layer deposition-like process or a pulsed deposition process or a combination of an atomic layer deposition-like process / pulsed deposition process and a chemical vapor deposition process; 2. The method of depositing tungsten on high aspect ratio structures of claim 1, wherein said second deposition step is performed using a chemical vapor deposition process.

8. 2. The method of depositing tungsten in high aspect ratio structures of claim 1, wherein the first deposition step deposits a tungsten nucleation layer or a tungsten nucleation layer and a portion of a tungsten bulk layer.

9. 2. The method of depositing tungsten in high aspect ratio structures of claim 1, further comprising repeatedly performing said treatment step and said second deposition step to fill a greater portion of said recessed structure.

10. 10. The method of claim 9, wherein a process gas flow rate or process time in a current process step is less than a process gas flow rate or process time in a previous process step.

11. 10. The method of claim 9, wherein a process time of a current second deposition step is less than a process time of a previous second deposition step.

12. 10. The method of claim 9, wherein a process time of the last second deposition step is greater than a process time of a previous second deposition step.

13. 10. The method of depositing tungsten in high aspect ratio structures of claim 9, further comprising performing the first deposition step after at least one of the second deposition steps when the processing step and the second deposition step are performed repeatedly.

14. 2. The method of depositing tungsten on high aspect ratio structures of claim 1, wherein the processing step includes a plurality of alternating processing and cleaning sub-steps, the processing sub-steps including flowing a processing gas and the cleaning sub-steps including flowing an inert gas.

15. 15. The method of depositing tungsten on high aspect ratio structures of claim 14, wherein the process time of the treatment substep or the cleaning substep is less than 60 s.

16. 15. The method of depositing tungsten on high aspect ratio structures of claim 14, wherein the process time of the treatment substep or the cleaning substep is less than 10 s.

17. The process gas is SF ６ , N.F. ３ 2. The method of claim 1, wherein the gas selected from the group consisting of HCl, fluorocarbon compounds, fluorohydrocarbon compounds, fluorooxygen compounds, chlorocarbon compounds, chlorinated hydrocarbon compounds, chlorinated oxygen compounds, or mixtures thereof.

18. 2. The method of depositing tungsten on high aspect ratio structures as recited in claim 1, wherein the processing step includes multiple processing operations, and the processing effect of each processing operation is adjustable.

19. The process conditions for each treatment were the same.

20. The method of depositing tungsten on high aspect ratio structures of claim 18, wherein alternatively, the processing time of each processing operation is decreased stepwise, and / or the pressure of each processing operation is increased stepwise, and / or the gas flow rate is decreased stepwise.

20. 2. The method of claim 1, wherein the pressure range of the first deposition step is 1-30 Torr and the pressure range of the second deposition step is 5-100 Torr.

21. 1. A method for depositing tungsten in high aspect ratio structures, comprising: The high aspect ratio structure is a recessed structure recessed downwardly from a surface of a substrate and having an aspect ratio of greater than 50:1, and the method of depositing tungsten comprises: a first deposition step of depositing a tungsten nucleation layer on the sidewalls and bottom of the recessed structure; A process step of flowing a process gas containing fluorine / chlorine radicals and radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen at a flow rate range of 1 to 200 sccm onto the surface of the substrate, forming a tungsten growth inhibition region by the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen and at least a portion of the region of the tungsten nucleation layer deposited on the sidewall of the recessed structure; and a second deposition step of depositing a layer of tungsten material within the recessed structure treated in the treatment step so as to fill at least a portion of the recessed structure with tungsten.

22. 22. The method of depositing tungsten in high aspect ratio structures of claim 21, wherein the first deposition step is performed using an atomic layer deposition-like process and / or a pulsed deposition process, and the second deposition step is performed using a chemical vapor deposition process.

23. 22. The method of depositing tungsten in high aspect ratio structures of claim 21, wherein the thickness of the tungsten nucleation layer deposited in the first deposition step is less than 150 Angstroms.

24. 2. The method of depositing tungsten on high aspect ratio structures of claim 1, wherein the processing step includes a plurality of alternating processing and cleaning sub-steps, the processing sub-steps including flowing a processing gas and the cleaning sub-steps including flowing an inert gas.

25. 22. The method of depositing tungsten on high aspect ratio structures of claim 21, wherein the processing step has a time range of 0-30 s.

26. The process gas is SF ６ , N.F. ３ 22. The method of depositing tungsten on high aspect ratio structures of claim 21, wherein the gas is selected from one of the following gases or a mixture thereof: HCl, a fluorocarbon compound, a fluorohydrocarbon compound, a fluorooxygen compound, a chlorocarbon compound, a chlorinated hydrocarbon compound, a chlorinated oxygen compound.

27. 22. The method of depositing tungsten in high aspect ratio structures of claim 21, further comprising repeatedly performing said treatment step and said second deposition step to fill a greater portion of said recessed structure.

28. 28. The method of depositing tungsten on high aspect ratio structures of claim 27, wherein a process gas flow rate or process time in a current process step is less than a process gas flow rate or process time in a previous process step, and / or a process time of a current second deposition step is less than a process time of a previous second deposition step.

29. 30. The method of claim 27, wherein a process time of the last second deposition step is greater than a process time of a previous second deposition step.

30. 30. The method of depositing tungsten in high aspect ratio structures of claim 27, further comprising performing the first deposition step after at least one of the second deposition steps when the processing step and the second deposition step are performed repeatedly.

31. A semiconductor substrate including a layer of material on a surface thereof, 2. A semiconductor substrate comprising: a recessed structure having an aspect ratio of greater than 50 formed in the material layer; the recessed structure having a barrier layer on a sidewall and a bottom wall; an internal space of the recessed structure surrounded by the barrier layer being filled with a tungsten material layer from the bottom to the top, forming a low resistance path from the bottom of the recessed structure to the top of the recessed structure; and the tungsten material layer is manufactured by the method of depositing tungsten in a high aspect ratio structure according to claim 1.

32. 32. The semiconductor substrate of claim 31, wherein the inside of the tungsten material layer has a plurality of gaps separated from each other and distributed vertically, and the height of each of the gaps is less than 1 / 4 of the height of the recessed structure.

33. A semiconductor substrate including a layer of material on a surface thereof, a recess structure having an aspect ratio greater than 50 is formed in the material layer, the recess structure having a barrier layer on a sidewall and a bottom wall, an internal space of the recess structure surrounded by the barrier layer is filled with a tungsten material layer from bottom to top to form a low resistance path from the bottom of the recess structure to the top of the recess structure, an inside of the tungsten material layer includes a plurality of gaps separated from each other and distributed vertically, and a height of each of the gaps is less than ¼ of a height of the recess structure.

Images