Method for depositing tungsten on a high aspect ratio structure and semiconductor substrate

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 semiconductor field, and specifically relates to a method for depositing tungsten in a high-aspect-ratio structure and a semiconductor substrate.

BACKGROUND ART

[0002] In memory devices, tungsten is mainly applied to word lines and contacts of 3D NAND. 3D NAND is formed of a plurality of stacked layers. As the integration degree of devices increases, the number of stacked layers of 3D NAND also increases, and the size of the feature regions serving as word lines and contacts is decreasing. At present, 128 stacked layers are the mainstream in 3D NAND, and accordingly, the feature regions have a very high aspect ratio, and the reduction in the size of the feature regions brings great challenges to the tungsten deposition process and apparatus.

[0003] In the conventional tungsten deposition process, when a general tungsten deposition process is performed on a feature region having a high aspect ratio (>50:1), a tungsten material layer as a seed crystal or a nucleation layer is usually deposited in the feature region first, and then a plurality of tungsten filling layers are sequentially deposited in the feature region. However, with the reduction of the feature size of the feature region structure and the increase in the number of stacked layers, it is difficult for the conventional solution to ensure the filling effect of the feature region, and large slits still exist 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. If the position of the slit inside the feature region is too high, the slit will be exposed during the CMP process, and the CMP slurry will enter the slit to erode the tungsten filling layer, causing loss of the tungsten filling material, reducing the electrical performance and service life of the entire device, and further causing an increase in 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 a high aspect ratio structure and a semiconductor substrate. The method involves depositing tungsten material in a recessed structure with an aspect ratio greater than 50, and combines a first deposition step, a processing step, and a second deposition step to process the tungsten material layer with a processing gas, etching the surface of the tungsten material layer with fluorine / chlorine-containing radicals in the processing gas to increase the top opening of the recessed structure, which facilitates subsequent filling of tungsten material, and forming 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 processing gas, which slows the deposition of subsequent tungsten material at the site of the surface bonds, further avoiding premature closure of the top opening of the recessed structure, moving and reducing the slits in the recessed structure downward, avoiding exposure of the slits in the subsequent CMP processing process, which helps improve the service life and electrical performance of the semiconductor substrate. On the other hand, this method does not form a new observable thin film layer on the tungsten material layer and does not adversely affect the semiconductor substrate.

[0005] To achieve the above objective, the present invention is realized by the following technical means.

[0006] A method for depositing tungsten on a high aspect ratio structure, wherein the high aspect ratio structure is recessed downward from the surface of the substrate and has an aspect ratio greater than 50:1, and the method for depositing tungsten is as follows: A first deposition step involves depositing a tungsten material layer of a first thickness of 10 to 500 angstroms on the side walls and bottom of the aforementioned recessed structure. A processing step involves flowing a processing gas containing fluorine / chlorine radicals and radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen, with a flow rate range of 1 to 200 sccm, onto the surface of the substrate, thereby forming a tungsten growth suppression region with the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen and at least a portion of the tungsten material layer deposited on the sidewall of the recessed structure. The process includes a second deposition step of depositing a tungsten material layer of a second thickness within the recessed structure processed in the processing step, such that at least a portion of the recessed structure is filled with tungsten.

[0007] Selectively, the tungsten growth-inhibiting region includes a region that extends from the surface of the substrate along the sidewall of the recessed structure toward the bottom of the recessed structure to a first depth which is two-thirds or less of the depth of the recessed structure.

[0008] Selectively, the processing gas etches a tungsten material layer at a second depth, which is less than or equal to the first depth, on the top sidewall of the recessed structure with fluorine / chlorine-containing radicals.

[0009] Selectively, the time range for the processing step is 0 to 180 seconds.

[0010] Selectively, the time range for the processing step is 0 to 40 seconds.

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

[0012] Selectively, the first deposition step is carried out using an atomic layer deposition-like process, 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] Selectively, in the first deposition step, a tungsten nucleation layer or a tungsten nucleation layer and a portion of the tungsten bulk layer are deposited.

[0014] Selectively, the process further includes repeating the processing step and the second deposition step to fill a larger portion of the recessed structure.

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

[0016] Selectively, the process time for the current second deposition step is shorter than the process time for the previous second deposition step.

[0017] Selectively, the process time of the last second deposition step is longer than the process time of the previous second deposition step.

[0018] If the processing step and the second deposition step are selectively repeated, this further includes performing the first deposition step at least once after the second deposition step.

[0019] Selectively, the processing step includes a plurality of alternating processing substeps and purification substeps, wherein a processing gas is passed through the processing substeps and an inert gas is passed through the purification substeps.

[0020] Selectively, the process time of the processing substep or the purification substep is less than 60 seconds.

[0021] Selectively, the process time of the processing substep or the purification substep is less than 10 seconds.

[0022] Selectively, the processing gas is selected from one of SF6, NF3, HCl, carbon fluoride compounds, hydrocarbon fluoride compounds, oxygen fluoride compounds, carbon chloride compounds, chlorinated hydrocarbon compounds, and oxygen chloride compounds, or a mixture thereof.

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

[0024] Selectively, the process conditions for each processing operation are the same. Alternatively, the processing time of each processing operation decreases stepwise, and / or the pressure of each processing operation increases stepwise, and / or the gas flow rate decreases stepwise.

[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 for depositing tungsten on a high-aspect-ratio structure, wherein the high-aspect-ratio structure is a recessed structure that is recessed downward from the surface of a substrate and has an aspect ratio greater than 50:1, and the method for depositing tungsten comprises: a first deposition step of depositing a tungsten nucleation layer on the sidewalls and bottom of the recessed structure; a processing step of flowing a processing gas, which contains radicals comprising fluorine / chlorine and radicals comprising at least one of carbon, sulfur, nitrogen, hydrogen or oxygen and has a flow rate range of 1 to 200 sccm, over the surface of the substrate, so that a tungsten growth inhibition region is formed by the radicals comprising at least one of carbon, sulfur, nitrogen, hydrogen or oxygen and at least a partial region of the tungsten nucleation layer deposited on the sidewalls of the recessed structure; a second deposition step of depositing a tungsten material layer in the recessed structure processed in the processing step, so as to fill at least a partial region of the recessed structure with tungsten.

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

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

[0029] Selectively, the processing step includes a plurality of alternating processing substeps and purification substeps, wherein a processing gas is passed through the processing substeps and an inert gas is passed through the purification substeps.

[0030] Selectively, the time range for the processing step is 0 to 30 seconds.

[0031] Selectively, the processing gas is selected from one of SF6, NF3, HCl, carbon fluoride compounds, hydrocarbon fluoride compounds, oxygen fluoride compounds, carbon chloride compounds, chlorinated hydrocarbon compounds, and oxygen chloride compounds, or a mixture thereof.

[0032] Selectively, the process further includes repeating the processing step and the second deposition step to fill a larger portion of the recessed structure.

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

[0034] Selectively, the process time of the last second deposition step is longer than the process time of the previous second deposition step.

[0035] If the processing step and the second deposition step are selectively repeated, this further includes performing the first deposition step at least once after the second deposition step.

[0036] A semiconductor substrate that selectively includes a material layer on its surface, A recessed structure with an aspect ratio greater than 50 is formed in the material layer, the recessed structure has barrier layers on its side walls and bottom wall, and the internal space of the recessed structure surrounded by the barrier layers is filled with a tungsten material layer from the bottom to the top, forming a low-resistance passage from the bottom to the top of the recessed structure, and the tungsten material layer is manufactured by depositing tungsten into a high aspect ratio structure.

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

[0038] Selectively, a semiconductor substrate having a material layer on its surface, wherein a recessed structure with an aspect ratio greater than 50 is formed in the material layer, the recessed structure has barrier layers on its side walls and bottom wall, the internal space of the recessed structure surrounded by the barrier layers is filled with a tungsten material layer from bottom to top, forming a low-resistance passage from the bottom to the top of the recessed structure, the interior of the tungsten material layer includes a plurality of gaps that are separated from each other and distributed vertically, the height of each gap being less than 1 / 4 of the height of the recessed structure.

[0039] The present invention has the following advantages compared to the conventional technology.

[0040] The present invention relates to a method for depositing tungsten in a high aspect ratio structure and a semiconductor substrate, wherein tungsten material is deposited in a recessed structure with an aspect ratio greater than 50. The method combines a first deposition step, a processing step, and a second deposition step, wherein in the processing step, the tungsten material layer formed in the first deposition step is processed with a processing gas, and the surface of the tungsten material layer is etched by fluorine / chlorine-containing radicals in the processing gas to increase the top opening of the recessed structure, which can facilitate subsequent filling of tungsten material. Furthermore, surface bonds are formed on the surface of the tungsten material layer adjacent to the opening of the recessed structure by radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen in the processing gas, thereby delaying the growth of the tungsten material layer in the second deposition step and forming a tungsten growth inhibition region on the sidewall of the recessed structure. By controlling the flow rate range of the processing gas in the processing step to 1-200 sccm, the depth to which active radicals enter the recessed structure can be controlled, and the depth of the tungsten growth inhibition region can be controlled. This method further avoids premature closure of the top opening of the recessed structure, moves and reduces the slit within the recessed structure downwards, and prevents the slit from being exposed during the subsequent CMP processing process, thereby improving the lifespan and electrical performance of the semiconductor substrate and minimizing power loss and overheating in integrated circuit design. On the other hand, this method does not form a new observable thin film layer on the tungsten material layer and does not adversely affect the semiconductor substrate.

[0041] Furthermore, the processing step of this method can act on the tungsten nucleation layer so that the subsequent tungsten bulk layer tends to deposit in the middle to lower part of the internal space of the recessed structure, and further ensure that the slits within the recessed structure are moved downward and reduced in size.

[0042] Furthermore, this method employs a system that repeats multiple steps to gradually fill and grow tungsten within the recessed structure, dividing a large slit within the recessed structure into multiple smaller slits and further shifting the position of the slits in the recessed structure downwards. This prevents the slits from being exposed during the subsequent CMP processing process and avoids erosion of the tungsten material layer within the recessed structure. [Brief explanation of the drawing]

[0043] [Figure 1] This is a schematic diagram of a part of the semiconductor substrate of the present invention. [Figure 2] This is a schematic diagram of the method for depositing tungsten on a high aspect ratio structure according to the present invention. [Figure 3] This is a schematic diagram of a tungsten deposition process in which the processing step of the present invention is performed once. [Figure 4] This is a schematic diagram of a tungsten deposition process in which the processing step in another embodiment is performed once. [Figure 5] This is a schematic diagram of a tungsten deposition process in which the processing steps in the present invention are performed multiple times. [Figure 6] This is a schematic diagram of a tungsten deposition process in which the processing steps in the present invention are performed multiple times. [Figure 7] This is a schematic diagram of another embodiment of a method for depositing tungsten on a high aspect ratio structure. [Modes for carrying out the invention]

[0044] To further clarify the object, technical means, and advantages of the embodiments of the present invention, the technical means in the embodiments of the present invention will be described clearly and completely below with reference to the drawings of the embodiments. Clearly, the embodiments described are only some, and not all, embodiments of the present invention. All other embodiments obtained based on the embodiments of the present invention without the creative effort of a person skilled in the art are all within the scope of the protection of the present invention.

[0045] In this specification, the terms “includes,” “contains,” “possesses,” or any other variation thereof are intended to cover the non-exclusive “includes,” thereby including not only those elements but also other elements not explicitly listed, or elements specific to such process, method, article, or terminal device. Unless otherwise specified, the elements limited by the phrase “includes” or “contains” are not excluded from the existence of other elements in the process, method, article, or terminal device containing those elements.

[0046] It should be noted that the drawings are all in a highly simplified format and use inaccurate proportions, and are merely intended to facilitate, clarify, and supplement the explanation of the embodiments of the present invention.

[0047] Figure 1 is a schematic diagram of a part of the semiconductor substrate 100 of the present invention. As shown in Figure 1, the semiconductor substrate 100 includes a material layer 101 (e.g., silicon oxide) on its surface, and the material layer 101 has multiple recessed structures 102, i.e., feature regions, with an aspect ratio greater than 50. The recessed structures 102 may be porous or grooved, and have barrier layers 103 on their sidewalls and bottom walls, and may be titanium nitride (TiN) layers as an example. The internal space enclosed by the barrier layer 103 needs to be filled with a tungsten material layer from bottom to top to form a low-resistance passage from the bottom to the top of the recessed structure 102. However, as technology nodes increase day by day, the demand for deposition processes of tungsten material layers within high aspect ratio recessed structures 102 is also increasing.

[0048] In the tungsten deposition process, during deposition, more tungsten material is deposited near the top opening of the recessed structure 102 compared to the bottom of the recessed structure 102, forming an overhang at the top opening. As the deposition process progresses, the overhang gradually grows, and the top opening of the recessed structure 102 closes prematurely, resulting in a large slit inside the recessed structure 102. Therefore, to ensure the deposition effect of the tungsten material layer, a conformal suppression process can be performed to suppress the recessed structure 102, preventing the top opening region of the recessed structure 102 from being pinched off in subsequent deposition processes. However, performing the conformal suppression process introduces a high-resistance layer of a certain thickness, and since this high-resistance layer is recognizable and detectable, it significantly affects the conductivity of the tungsten material layer, preventing the formation of low-resistance passages in the semiconductor substrate 100 and further increasing device losses.

[0049] To ensure good electrical performance and service life of the semiconductor substrate 100, the present invention provides a method for depositing tungsten on a high aspect ratio structure, the high aspect ratio structure being a recessed structure 102 that is recessed downward from the surface of the substrate and has an aspect ratio greater than 50:1, and the method of the present invention is also highly effective for recessed structures with an aspect ratio less than 50:1, and because unwanted slits 205 or holes tend to appear inside when depositing tungsten on a recessed structure 102 with an aspect ratio greater than 50:1, the present invention will be explained using the example of a recessed structure 102 with an aspect ratio greater than 50:1.

[0050] As shown in Figures 2 to 7, the method for depositing tungsten on a high aspect ratio structure according to the present invention includes: a first deposition step of depositing a tungsten material layer of first thickness, which is 10 to 500 angstroms, on the sidewalls and bottom of a recessed structure 102; a treatment step of flowing a treatment gas containing radicals containing fluorine or chlorine and radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen, with a flow rate range of 1 to 200 sccm, over the surface of the substrate to form a tungsten growth inhibiting region 201 with the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen and at least a portion of the tungsten material layer deposited on the sidewalls of the recessed structure 102; and a second deposition step of depositing a tungsten material layer of second thickness within 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 involves depositing a tungsten material layer inside the recessed structure 102 (barrier layer 103), then flowing a processing gas to treat the surface of the tungsten material layer, and etching the tungsten material layer in the top opening region of the recessed structure 102 with fluorine / chlorine-containing radicals in the processing gas, thereby increasing the size of the top opening region and preventing premature closure of the inside of the recessed structure 102 in subsequent processes. Furthermore, the tungsten material layer is etched by radicals in the processing gas that contain at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen. Surface bonds are formed on the surface of the tungsten material layer, and the regions where surface bonds are formed delay the growth of the tungsten material layer in the second deposition step. A tungsten material layer deposition delay region, i.e., a tungsten growth suppression region 201 (the dotted region on the side wall of the recessed structure 102 in Figure 3), is formed on the side wall of the recessed structure 102. By controlling the flow rate range and the duration of the processing gas flow in the processing step, the depth to which 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 suppression region 201 can be controlled. The presence of these surface bonds delays / suppresses the deposition of subsequent tungsten material layers at that location, but no new observable thin film is formed, and the electrical performance of the semiconductor substrate 100 is not affected. The flow rate range of the processing gas in the present invention is 1 to 200 sccm. If the internal pressure of the chamber does not change and the flow rate of other inert gases inside the chamber does not change, the concentration of the processing gas at the top of the recessed structure 102 can be controlled by controlling the flow rate of the processing gas, and furthermore, the diffusion rate of the processing gas within the recessed structure 102 can be controlled. Because the flow rate of the processing gas in the processing step of the present invention is low and the flow time is short, for example, 0 to 180 seconds, the depth to which radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen diffuse into the interior of the recessed structure 102 is limited, and the tungsten growth inhibition region 201 is formed only on the side wall at a certain distance below the opening of the recessed structure 102.By controlling the flow rate and time of the processing gas, the deposition of the tungsten material layer in the top opening region of the recessed structure 102 and the side wall region adjacent to the top opening of the recessed structure 102 to a certain depth is delayed in the second deposition step. In the subsequent second deposition step, the tungsten material layer is preferentially deposited in the lower and middle parts of the recessed structure 102, excluding the tungsten growth suppression region 201. This delays the closure of the opening of the recessed structure 102, reduces the height of the slit 205 within the recessed structure 102, and moves the position of the slit 205 downward (to the lower and middle parts of the recessed structure 102). This reduces the risk of the slit 205 being exposed prematurely and subjected to slurry attack during the CMP process, improves the service life of the semiconductor substrate 100, and ensures good low-resistance passages.

[0052] As shown in Figure 3, the tungsten growth suppression region 201 includes a region extending from the surface of the semiconductor substrate 100 along the sidewall of the recessed structure 102 toward the bottom of the recessed structure 102 by a first depth, and at least a portion of the surface of the top of the semiconductor substrate 100. Selectively, the first depth is two-thirds or less of the depth of the recessed 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 have difficulty entering the small-sized recessed structures 102. The etching effect by fluorine / chlorine-containing radicals and the density of surface bonds formed on the tungsten material layer of the first thickness by radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen gradually weaken downwards from the top of the recessed structure 102. Therefore, the effect of the processing gas received in the above processing step is most pronounced on the tungsten material layer in the top region of the recessed structure 102. Because the tungsten deposition inhibition effect of surface bonds received by the tungsten material layer in the top region is most pronounced, tungsten deposition in the top region is most significantly delayed in the subsequent tungsten deposition process so that tungsten material is preferentially deposited in the bottom region of the recessed structure 102.

[0054] In actual applications, the diffusion of components in the processing gas can be controlled as needed based on differences in the components of each component. For example, the component content of radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen in the processing gas can be increased so that radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen passivate the tungsten material layer to a first depth in the sidewall of the recessed structure 102. The processing gas can also be made smaller than the first depth, i.e., the range of the tungsten growth suppression region 201 can be made larger than the range of the etching region, so that the second depth is smaller than the first depth, i.e., the range of the tungsten growth suppression region 201 can be made larger than the range of the etching region, so that the second depth is equal to the first depth.

[0055] As shown in Figure 3, in this embodiment, the tungsten material layer of first thickness deposited in the first deposition step is a tungsten nucleation layer 202, and the tungsten material layer of 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 a processing gas, and the etching thickness is smaller than the first thickness of the tungsten nucleation layer 202 in that layer. This forms a tungsten growth suppression region 201 on the surface of the tungsten nucleation layer 202 at the top of the recessed structure 102, further suppressing the deposition of the tungsten bulk layer 203 at the top of the subsequent recessed structure 102. This closes the opening of the recessed structure 102 early, avoiding pinch-off of the tungsten material deposition path in the recessed structure 102. Furthermore, no observable new thin film is formed in the tungsten growth suppression region 201, resulting in a small impact on the electrical performance within the recessed structure 102, which helps ensure good performance of the semiconductor device.

[0056] The first deposition step can be selectively performed using an atomic layer deposition-like process and / or a pulsed deposition process, and the second deposition step can be performed using a chemical vapor deposition (CVD) process. In other words, different deposition processes can be used for the tungsten nucleation layer 202 and the tungsten bulk layer 203, and both can be selectively performed in the same chamber.

[0057] Specifically, in the atomic layer deposition-like process, one or more reducing agents, a purge gas, a tungsten-containing precursor, and a purge gas are sequentially flowed into the chamber, and this process is repeated periodically until a desired thickness is obtained, thereby forming a tungsten nucleation layer 202, i.e., a thin conformal nucleation layer to be subsequently deposited, by the 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 tungsten film 204 with low resistivity. In the pulse deposition process, one or more reducing agents and a tungsten-containing precursor are simultaneously flowed into the chamber, then a purge gas is flowed, and this process is repeated periodically until a tungsten nucleation layer 202 of the desired thickness is obtained.

[0058] The atomic layer deposition-like process and pulse deposition process described above are not limited to those described above, and the process steps can be adjusted according to actual process conditions or application requirements. The present invention is not limited thereto. Exemplaryly, an atomic layer deposition-like process in one embodiment includes a step S1 of flowing B2H6 / SiH4 (reducing agent 1) + H2 (reducing agent 2), a step S2 of purging with an inert gas, a step S3 of flowing tungsten-containing precursor + H2 (reducing agent 2), a step S4 of purging with an inert gas, and a step of repeatedly performing steps S1 to S4. In this embodiment, reducing agent 2 has weaker reaction activity with the tungsten-containing precursor compared to reducing agent 1, and increases the diffusion time of the tungsten-containing precursor, resulting in a more uniform distribution of the tungsten-containing precursor above the semiconductor substrate 100. The actual deposition rate of the atomic layer deposition-like process is selectively adjusted to be greater than that of a typical atomic layer deposition process in order to improve the deposition rate of the tungsten nucleation layer 202. In practical applications, an appropriate deposition process can be selected in the first deposition step, depending on the process requirements and equipment conditions, to form a tungsten nucleation layer 202 that meets the actual requirements.

[0059] Selectively, the process pressure range for the first deposition step is 1 to 30 Torr, the process temperature range is 300 to 400°C, and the thickness of the tungsten nucleation layer 202 is less than 150 angstroms. For the deposition of tungsten material in a high aspect ratio structure, excessively thick material should not be deposited in the initial stage. Otherwise, it would be equivalent to reducing the size of the opening at the top of the recess structure 102, affecting gas diffusion during subsequent deposition and impacting the filling effect of the recess structure 102. When depositing the tungsten nucleation layer 202 using an atomic layer deposition-like process, the cycle time is long, the response to switching the deposition rate is slow, and the thickness of the initially deposited tungsten nucleation layer 202 directly affects the filling rate of the tungsten material throughout the recess structure 102, and further affects the processing capacity of the semiconductor substrate 100 by the processing device. Therefore, the film thickness formed by depositing 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, a processing gas is flowed, and the processing gas is dissociated by a remote plasma device to treat the surface of the tungsten nucleation layer 202. In the processing step, the tungsten nucleation layer 202 is etched by fluorine / chlorine-containing radicals in the processing gas, and its etching thickness is less than the thickness of the preceding tungsten nucleation layer 202. On the other hand, the tungsten bulk layer 203 cannot be deposited directly onto the barrier layer 103 of the semiconductor substrate 100, and it is necessary to deposit the tungsten nucleation layer 202 beforehand. Several dangling bonds exist on the surface of the tungsten nucleation layer 202, and these dangling bonds generally allow the tungsten bulk layer 203 to adhere well to the tungsten nucleation layer 202, allowing the subsequent tungsten material to grow. In the processing step of the present invention, radicals in the processing gas containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen combine with dangling bonds in the tungsten growth suppression region 201 on the surface of the tungsten nucleation layer 202 to form surface bonds, thereby preventing the tungsten bulk layer 203 from combining with the dangling bonds of the tungsten nucleation layer 202 in that region, thereby delaying the deposition of subsequent tungsten bulk layers 203 at that location. If it is necessary to continue growing tungsten material in the tungsten growth inhibition region 201, it is necessary to reform the dangling bond at this location. For example, when depositing a tungsten bulk layer 203 using a chemical vapor deposition process in the subsequent second deposition step, reforming the dangling bond at this location requires a certain reaction time. However, since the tungsten bulk layer 203 is deposited normally in areas other than the tungsten growth inhibition region 201 within this reaction time, the treatment gas causes a tungsten growth delay of several tens of seconds or even several thousand seconds in the tungsten growth inhibition region 201 from the perspective of tungsten material deposition across the entire recessed structure 102 (the delay time is determined by the treatment intensity of the treatment gas and the specific process of subsequent tungsten material deposition).

[0061] Selectively, the flow rate range of the process gas in the processing step is 1 to 200 sccm, the process pressure range is 1 to 30 Torr, the process temperature range is 300 to 400°C, and the process time range is 0 to 40 s. However, the present invention does not limit the above parameters, and the above parameters can be controlled as needed in order to achieve the optimal processing effect. For example, in another embodiment, the time range of the processing step is set to 0 to 30 s in order to adjust the processing intensity of the process gas. Furthermore, selectively, the process gas includes, but is not limited to, one of SF6, NF3, HCl, carbon fluoride compounds (e.g., CF4, CHF3, C2F4), fluorinated hydrocarbon compounds, oxygen fluoride compounds, carbon chloride compounds, chlorinated hydrocarbon compounds, and oxygen chloride compounds, or a mixture thereof. That is, the process gas is a gas or gasified precursor containing at least fluorine / chlorine and one of 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 a tungsten-containing precursor are simultaneously flowed into the chamber, and using the chemical vapor deposition process, the reducing agents and tungsten-containing precursor deposit a tungsten bulk layer 203 of second thickness onto the tungsten nucleation layer 202 treated by the processing gas. By treating the radicals in the processing gas in the processing step, which contain at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen, a tungsten growth inhibition region 201 is formed on the surface of the side wall at a certain depth below the top opening of the recessed structure 102. In the second deposition step, the tungsten material 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 moves and shrinks the slit 205 within the recessed structure 102 downwards. Selectively, 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 precursors and reducing agents are not limited to those described above, and other reagents may be used as long as a similar deposition effect is achieved. For example, as the tungsten-containing precursor, WC 16A reducing agent such as silane or diborane is used. Selectively, the pressure range for the second deposition step is 5 to 100 Torr, and the process temperature range is 300 to 400°C.

[0063] After the second deposition step is completed, 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 recess structure 102, i.e., the tungsten material layer fills the bottom of the recess structure 102. The present invention delays the growth of the tungsten material layer in the region adjacent to the opening of the recess structure 102 by setting a processing step between the first deposition step and the second deposition step, thereby etching the tungsten material layer at the opening with fluorine / chlorine-containing radicals in the processing gas after depositing a thin tungsten material layer in the first deposition step, and forming tungsten growth inhibiting regions 201 on the surface of the tungsten material layer deposited on the side walls adjacent to the opening of the recess structure 102 with radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen in the processing gas, thereby ensuring that more deposition gas enters the bottom of the high aspect ratio recess structure 102 in the second deposition step to grow the tungsten material layer. Although it is not possible to completely remove the elongated gaps within the tungsten material layer, the length of the elongated gaps in the recessed structure 102 can be shortened, and by delaying the closing of the opening of the recessed structure 102, the upper end of the formed elongated gap comes as close as possible to the bottom of the recessed structure 102. Furthermore, exposure of the elongated gaps when chemical mechanical grinding (CMP) is performed on the surface of the semiconductor substrate 100 is avoided, thereby improving the performance of the semiconductor substrate 100.

[0064] Of course, the types of tungsten material layers are not limited to those described above, and other configurations are possible. For example, in another embodiment, as shown in Figure 4, the tungsten material layer deposited in the first deposition step is a tungsten nucleation layer and a portion of the tungsten bulk layer (which may be called a tungsten film 204). That is, a single layer of tungsten film 204 is formed first, and a processing step is performed on the tungsten bulk layer of the tungsten film 204 to form a tungsten growth suppression region 201, thereby achieving surface treatment and avoiding premature pinching off of the subsequent tungsten deposition path. After surface treatment of the tungsten film 204, the deposition of subsequent tungsten material layers continues, forming small slits 205 inside the recessed structure 102, thus avoiding erosion of the tungsten material due to exposure of the slits 205 during subsequent CMP processing. Selectively, in the first deposition step of this embodiment, the tungsten film 204 may be deposited using an atomic layer deposition-like process, a pulse deposition process, or a combination of an atomic layer deposition-like process / pulse deposition process and a chemical vapor deposition process. Details of the specific steps of each process can be found in the description above, which is omitted here. Further selectively, in this embodiment, the thickness range of the tungsten film 204 deposited in the first deposition step is 10 to 500 angstroms, the temperature range of the tungsten nucleation layer 202 deposition process is 300 to 400°C, the process pressure range is 5 to 100 Torr, and in this embodiment, the etching thickness of the processing gas in the processing step is smaller than the thickness of the preceding tungsten film 204.

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

[0066] Of course, the processing step may be performed multiple times during tungsten deposition, for example, by performing the processing step twice. As shown in Figures 5 and 6, the method for depositing tungsten on a high aspect ratio structure of the present invention further includes repeating the processing step and the second deposition step to fill more of the recessed structure 102. Selectively, the etching thickness of each processing step is smaller than the thickness of the remaining tungsten nucleation layer 202 and / or the tungsten bulk layer 203. Using multiple processing steps allows for continuous processing of the tungsten material layer in the top region of the recessed structure 102, and in the tungsten deposition step after the processing step, the large slit 205 in the recessed structure 102 is divided into multiple smaller slits 205, ensuring that the tungsten material always tends to deposit in the middle and lower parts of the recessed structure 102 without depositing in the top region of the recessed structure 102, further ensuring that the slits 205 in the recessed structure 102 move downward and shrink, improving the precision of control over the distribution of the slits 205. Selectively, the process time of the current second deposition step is shorter than that of the previous second deposition step, meaning the stepwise growth intensity of the tungsten material layer decreases sequentially, reducing the slit 205 during deposition. Selectively, the process time of the current second deposition step may be longer than that of the previous second deposition step, as this creates a situation where the remaining structure is filled all at once at the end.

[0067] As can be seen from the above, several dangling bonds exist on the surface of the tungsten nucleation layer 202, and these dangling bonds can better adhere 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, an additional layer of tungsten nucleation layer 202 may be deposited after the processing step and the second deposition step (see Figures 5 and 6). That is, if the processing step and the second deposition step are performed multiple times, the first deposition step may be performed at least once after the second deposition step, and an additional layer of tungsten nucleation layer 202 may be deposited before the processing step so as to better adhere the subsequent tungsten bulk layer 203 to the recessed structure 102.

[0068] Of course, depending on the actual process environment and product requirements, the above method can be repeated multiple times for filling, that is, a cycle of first deposition step - processing step - second deposition step is performed to achieve gradual growth of the tungsten material layer within the recessed structure 102. In the first cycle, a single layer of tungsten film 204 is grown on the bottom and side walls of the recessed structure 102. In the second cycle, a layer of tungsten film 204 is grown in the middle and lower part of the recessed structure 102. This continues until the Nth cycle, growing a layer of tungsten film 204 at the top of the recessed structure 102, dividing the large slit 205 within the recessed structure 102 into multiple smaller slits 205, and further moving the position of the slit 205 within the recessed structure 102 downwards, thereby preventing the slit 205 from being exposed in the subsequent CMP processing process and preventing erosion of the tungsten material layer within the recessed structure 102. The more times the above method is repeated, the smaller the slit 205 inside the tungsten material layer within the recessed structure 102 becomes, and the smaller the performance loss of the device is expected to be.

[0069] Repeating the processing step and the second deposition step multiple times solves the problem of difficulty in achieving both top and bottom filling effects in a single deposition step. The larger the aspect ratio of the recessed structure 102, the more likely it is that the bottom will be filled but there will be a large hole or slit 205 at the top, or the top will have a high filling effect but there will be a slit 205 at the bottom. By processing multiple times, it is possible to achieve both filling effects at each depth within the recessed structure 102, and by optimizing the process of each repeated step, the internal slit 205 can be effectively reduced and controlled to occur in a position close to the bottom of the recessed structure 102.

[0070] Selectively, during the process of performing the processing steps multiple times, the processing intensity in each processing step is progressively reduced (this can be achieved by increasing the process pressure and / or decreasing the processing time and / or decreasing the flow rate of the processing gas), ensuring that the slit 205 in the recessed structure 102 moves downward and shrinks, while reducing the effect of the processing steps on tungsten deposition. For example, the process conditions for the first processing step are 300°C, 5 torr, 10 sccm, and 30 s, and the process conditions for the second processing step are 300°C, 5 torr, 10 sccm, and 15 s.

[0071] In actual application, the depth range extending to the sidewalls of the recessed structure 102 of the tungsten growth suppression region 201 formed in the processing step affects the deposition position of the tungsten material in the subsequent second deposition step. Therefore, by controlling the depth range of the tungsten growth suppression region 201 in the processing step, the deposition position of the subsequent tungsten material can be controlled. In terms of gas diffusion, when the flow rate of the processing gas is small and the processing time is short, the processing gas preferentially diffuses and acts on the top of the recessed structure 102 and the sidewalls adjacent to the top, without diffusing into the middle and lower parts of the recessed structure 102. If the flow rate of the processing gas is low and the processing time is short, the total amount of processing gas is also low, and radicals in the processing gas containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen may not be able to saturate the surface of the tungsten material layer deposited in the first deposition step. That is, radicals in the processing gas containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen may not be able to bond with all the dangling bonds in the top region. In this case, the processing intensity of the processing gas is weakened, which reduces the delay effect of the tungsten growth inhibiting region 201. For example, it originally delays the growth of the tungsten material layer by several tens of seconds, but reduces the delay so that the tungsten material layer grows within 10 seconds, causing the phenomenon of premature closure of the top opening of the recessed structure 102.

[0072] Based on the above elements, as shown in Figure 7, the processing steps of the present invention include a plurality of alternating processing substeps and a purification substep. In the processing substeps, a processing gas is flowed to perform surface treatment, and in the purification substeps, an inert gas is flowed to perform purification. The purpose of purification is to remove the processing gas flowed in the processing substeps in a timely manner to prevent the processing gas from entering the recessed structure 102 to an excessive depth. By controlling the processing depth of each processing substep and the number of repetitions of each substep, the processing 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. On the other hand, by adjusting each substep based on the actual characteristics of the recessed structure 102, stepwise processing of the sidewalls of the top opening of the recessed structure 102 can be achieved, that is, the processing effect at different depth positions of the sidewalls can be made different.

[0073] Selectively, the process time of the treatment substep or purification substep is less than 60 s. Of course, the duration of the two substeps is not limited to the above and can be adjusted according to the actual process requirements, and the present invention does not limit this, for example, in another embodiment, the process time of the treatment substep or purification substep is less than 10 s. Further selectively, Ar may be used as the inert gas. Of course, other gases that do not affect the reaction may be used.

[0074] Furthermore, the processing steps in the present invention can be achieved by combining multiple processing operations, and the processing effect of each processing operation can be adjusted to achieve different degrees of processing effect. By not depositing a tungsten material layer between each processing operation and combining multiple processing operations to achieve a single complete processing step, the processing effect on the surface of the preceding tungsten material layer is improved without increasing the processing depth of the tungsten material layer in the recessed structure 102. Alternatively, by controlling each processing operation, a processing effect that changes with gradual depth changes can be achieved on the surface of the preceding tungsten material layer, further improving the tungsten material filling effect. Selectively, each processing operation includes one processing substep and one purification substep to further optimize the intensity of the processing gas and achieve precise control of its processing effect.

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

[0076] Of course, the process conditions for each processing operation may differ, and the processing effect of each processing operation can be gradually reduced by adjusting one or more process parameters. Selectively, the processing time for each processing operation can be gradually reduced. For example, the process conditions for the first processing operation may be 300°C, 5 torr, 10 sccm, 15 s, followed by Ar purging; the process conditions for the second processing operation may be 300°C, 5 torr, 10 sccm, 5 s, followed by Ar purging; ..., the process conditions for the Nth processing operation may be 300°C, 5 torr, 10 sccm, 3 s, followed by Ar purging.

[0077] In other embodiments, the processing effect may be adjusted by gradually increasing the pressure and / or gradually decreasing the gas flow rate in each processing operation. As the pressure increases or the gas flow rate decreases, the processing effect of each processing operation gradually weakens. By adjusting the process conditions of each processing operation, the etching and activation effect of the tungsten material layer by the processing gas is continuously improved, while the gradually decreasing effect of each processing operation does not increase the processing strength of the tungsten material layer for the entire processing step.

[0078] Furthermore, the processing effect of each processing operation is not limited to the above-mentioned gradual decrease trend, and can be designed according to actual product requirements; the present invention is not limited thereto. For example, due to the steric hindrance effect of gas diffusion and the properties of the processing gas radicals themselves, 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 downward from the top of the recessed structure 102. That is, the tungsten material layer on the side walls of the recessed structure 102 is less affected by the processing gas as the depth increases. However, in some application scenarios, when subsequent tungsten material layers are deposited, it is necessary to move the range of the tungsten growth suppression region 201 of the tungsten material layer on the side walls 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 side walls, and further prevent premature closure of the top opening of the recessed structure 102. Based on the above application requirements, the tungsten material layer of the recessed structure 102 can be pre-etched using the first processing operation to form surface bonds, and as can be seen above, the etching of the processing gas can increase the opening of the recessed structure 102, which provides convenient conditions for the subsequent processing gas to enter the interior of the recessed structure 102. During the subsequent processing operation, the gas 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 expand the depth to which the processing gas etches and activates the tungsten material layer at the side walls of the recessed structure 102, and further move the range of the tungsten growth suppression region 201 downward.

[0079] As can be seen from the above, when the tungsten material layer of the semiconductor substrate 100 is manufactured by the method of depositing tungsten on the high aspect ratio structure described above, the tungsten material layer can be filled from the bottom to the top of the recessed structure 102, the position of the slit 205 in the internal space is low and the slit 205 is small, which helps to create a low-resistance passage from the bottom to the top of the recessed structure 102.

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

[0081] In summary, the present invention provides a method for depositing tungsten on a high aspect ratio structure and a semiconductor substrate 100, which deposits tungsten material in a recessed structure 102 with an aspect ratio greater than 50. This method combines a first deposition step, a processing step, and a second deposition step, wherein the processing step involves processing the tungsten material layer formed in the first deposition step with a processing gas, and the fluorine / chlorine-containing radicals in the processing gas etch the surface of the tungsten material layer to increase the top opening of the recessed structure 102, which is useful for subsequent filling of tungsten material. Radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen in the processing gas form surface bonds on the surface of the tungsten material layer adjacent to the opening of the recessed structure 102. The regions where surface bonds are formed delay the growth of the tungsten material layer in the second deposition step, forming a tungsten growth suppression region 201 on the sidewall of the recessed structure 102. By controlling the flow rate range of the processing gas in the processing 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 also be controlled. This further avoids premature closure of the top opening of the recessed structure 102, moves and reduces the slit 205 within the recessed structure 102 downwards, prevents the slit 205 from being exposed in the subsequent CMP processing process, and helps improve the service life and electrical performance of the semiconductor substrate 100. On the other hand, this method does not form any new observable thin film layer on the tungsten material layer and does not adversely affect the semiconductor substrate 100.

[0082] Furthermore, the processing step of the method can act on the tungsten nucleation layer 202 so that the subsequent tungsten bulk layer 203 is deposited in the middle to lower part of the internal space of the recessed structure 102, and further ensure that the slit 205 within the recessed structure 102 is moved downward and reduced in size.

[0083] Furthermore, this method employs a system that repeats multiple steps to gradually fill and grow tungsten within the recessed structure 102, thereby dividing the large slit 205 within the recessed structure 102 into multiple smaller slits 205, and further moving the position of the slit 205 in the recessed structure 102 downwards. This prevents the slit 205 from being exposed during the subsequent CMP processing process and prevents erosion of the tungsten material layer within the recessed structure 102.

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

Claims

1. A method for depositing tungsten on a high aspect ratio structure, The aforementioned high aspect ratio structure is recessed downward from the surface of the substrate and is a recessed structure with an aspect ratio greater than 50:1, and the method for depositing tungsten is, A first deposition step involves depositing a tungsten material layer of a first thickness of 10 to 500 angstroms on the side walls and bottom of the recessed structure. A processing step involves flowing a processing gas containing fluorine / chlorine radicals and radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen, with a flow rate range of 1 to 200 sccm, onto the surface of the substrate, thereby forming a tungsten growth suppression region with the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen and at least a portion of the tungsten material layer deposited on the sidewall of the recessed structure. The process includes a second deposition step of depositing a tungsten material layer of a second thickness within the recessed structure processed in the processing step, such that at least a portion of the recessed structure is filled with tungsten, The processing step includes a plurality of alternating processing substeps and a purification substep, wherein a processing gas is flowed in the processing substeps, and an inert gas is flowed in the purification substeps so as to adjust the processing depth of the tungsten growth inhibition region. A method for depositing tungsten on a high aspect ratio structure characterized by the following.

2. The method for depositing tungsten on a high aspect ratio structure according to claim 1, characterized in that the tungsten growth suppression region includes a region that extends from the surface of the substrate along the side wall of the recessed structure toward the bottom of the recessed structure to a first depth which is two-thirds or less of the depth of the recessed structure.

3. The method for depositing tungsten on a high aspect ratio structure according to claim 2, characterized in that the processing gas etches a tungsten material layer having a second depth, which is less than or equal to the first depth, on the top side wall of the recessed structure with radicals containing fluorine / chlorine.

4. The method for depositing tungsten on a high aspect ratio structure according to claim 1, characterized in that the time range of the processing step is 0 to 180 s.

5. The method for depositing tungsten on a high aspect ratio structure according to claim 1, characterized in that the time range of the processing step is 0 to 40 s.

6. A method for depositing tungsten in a high aspect ratio structure according to claim 1, characterized in that the interior of the tungsten material layer filled in the second deposition step has elongated voids whose height is less than 60% of the depth of the recessed structure.

7. The first deposition step is carried out using an atomic layer deposition-like process, a pulse deposition process, or a combination of an atomic layer deposition-like process / pulse deposition process and a chemical vapor deposition process. A method for depositing tungsten on a high aspect ratio structure according to claim 1, characterized in that the second deposition step is carried out using a chemical vapor deposition process.

8. A method for depositing tungsten on a high aspect ratio structure according to claim 1, characterized in that in the first deposition step, a tungsten nucleation layer or a tungsten nucleation layer and a portion of the tungsten bulk layer are deposited.

9. A method for depositing tungsten on a high aspect ratio structure according to claim 1, further comprising repeating the processing step and the second deposition step to fill more of the recessed structure.

10. A method for depositing tungsten on a high aspect ratio structure according to claim 9, further comprising performing the first deposition step at least once after the second deposition step, when the processing step and the second deposition step are performed repeatedly.

11. The method for depositing tungsten on a high aspect ratio structure according to claim 1, characterized in that the process time of the processing substep or the purification substep is less than 60 s.

12. The method for depositing tungsten on a high aspect ratio structure according to claim 1, characterized in that the process time of the processing substep or the purification substep is less than 10 s.

13. The aforementioned processing gas is SF ６ NF ３ A method for depositing tungsten on a high aspect ratio structure according to claim 1, characterized in that the gas is selected from one of HCl, fluorinated carbon compounds, fluorinated hydrocarbon compounds, fluorinated oxygen compounds, chloride carbon compounds, chlorinated hydrocarbon compounds, and chlorinated oxygen compounds, or a mixture thereof.

14. The method for depositing tungsten on a high aspect ratio structure according to claim 1, characterized in that the processing step includes multiple processing operations, and the processing effect of each processing operation is adjustable.

15. The process conditions for each processing operation are the same. Alternatively, the method for depositing tungsten on a high aspect ratio structure according to claim 14, characterized in that the processing time of each processing operation is gradually reduced, and / or the pressure of each processing operation is gradually increased, and / or the gas flow rate is gradually reduced.

16. A method for depositing tungsten on a high aspect ratio structure according to claim 1, characterized in that 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.

17. A method for depositing tungsten on a high aspect ratio structure, The aforementioned high aspect ratio structure is recessed downward from the surface of the substrate and is a recessed structure with an aspect ratio greater than 50:1, and the method for depositing tungsten is, A first deposition step involves depositing a tungsten nucleation layer on the side walls and bottom of the aforementioned recessed structure, A processing step involves flowing a processing gas containing fluorine / chlorine radicals and radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen, with a flow rate range of 1 to 200 sccm, onto the surface of the substrate, thereby forming a tungsten growth suppression region with the radicals containing at least one of carbon, sulfur, nitrogen, hydrogen, or oxygen and at least a portion of the tungsten nucleation layer deposited on the sidewall of the recessed structure. The process includes a second deposition step of depositing a tungsten material layer within the recessed structure processed in the processing step, such that at least a portion of the recessed structure is filled with tungsten, The processing step includes a plurality of alternating processing substeps and a purification substep, wherein a processing gas is flowed in the processing substeps, and an inert gas is flowed in the purification substeps so as to adjust the processing depth of the tungsten growth inhibition region. A method for depositing tungsten on a high aspect ratio structure characterized by the following.

18. A method for depositing tungsten on a high aspect ratio structure according to claim 17, characterized in that the first deposition step is carried out using an atomic layer deposition-like process and / or a pulse deposition process, and the second deposition step is carried out using a chemical vapor deposition process.

19. A method for depositing tungsten on a high aspect ratio structure according to claim 17, characterized in that the thickness of the tungsten nucleation layer deposited in the first deposition step is less than 150 angstroms.

20. The method for depositing tungsten on a high aspect ratio structure according to claim 17, characterized in that the time range of the processing step is 0 to 30 s.

21. The aforementioned processing gas is SF ６ NF ３ A method for depositing tungsten on a high aspect ratio structure according to claim 17, characterized in that the gas is selected from one of HCl, carbon fluoride compounds, hydrocarbon fluoride compounds, oxygen fluoride compounds, carbon chloride compounds, chlorinated hydrocarbon compounds, and oxygen chloride compounds, or a mixture thereof.

22. A method for depositing tungsten on a high aspect ratio structure according to claim 17, further comprising repeating the processing step and the second deposition step to fill more of the recessed structure.

23. A method for depositing tungsten on a high aspect ratio structure according to claim 22, further comprising performing the first deposition step at least once after the second deposition step, when the processing step and the second deposition step are performed repeatedly.

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