Hot aluminum hole filling method and sputtering device

Abstract

The invention provides a hot aluminum hole filling method and a sputtering device. The method comprises the following steps: (1) sputtering titanium adhesion layer films on the side surface and the bottom surface of a to-be-filled hole of a structural sheet containing the to-be-filled hole; (2) sputtering a titanium nitride barrier layer metal film on the surface of the titanium adhesion layer film to obtain a precursor structure sheet; (3) growing a cold aluminum seed layer on the surface of the titanium nitride barrier layer metal film of the precursor structure sheet, and then growing a hot aluminum layer on the cold aluminum seed layer to complete hole filling; wherein sputtering in the step (1) and the step (2) uses a sputtering device with a collimator in a standard cavity. The titanium layer and the titanium nitride layer are sputtered by using the sputtering device with the collimator in the standard cavity, so that the step coverage rate of the connecting layer and the metal layer can be increased, and the spike problem of the aluminum filling hole is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor material processing and relates to a hot aluminum hole filling method and a sputtering device. Background Art

[0002] In order to provide a larger area of ​​interconnection for the MOS integrated circuit process, technicians introduced a more flexible multi-layer metal process. Although the conductivity of metal aluminum is good, there is a problem of poor step coverage when the aluminum filling plug is formed by sputtering, and the step coverage of sputtered aluminum decreases sharply as the aspect ratio of the hole increases. In the submicron design rules, the step coverage of contact holes and through holes must not be less than 20%, and the connection between each layer of metal relies on vertical interconnection through-hole plugs. The connection between each pole of CMOS and the metal is achieved by vertical contact hole plugs. It is the submicron standard process currently used in the industry. The aluminum plug technology has both reliability and practicality.

[0003] The aluminum filling process is to first deposit a titanium film as an adhesion layer to increase adhesion to the underlying layer, and then deposit a titanium nitride film barrier layer to prevent aluminum from reacting with the underlying SiO2 during filling, causing silicon to dissolve and diffuse in the aluminum. Because aluminum fills the silicon vacancies, it will cause the aluminum to sink and form spikes. This phenomenon is exacerbated as the aspect ratio increases, and the spikes formed will cause short circuits between metal interconnects.

[0004] CN114645245A discloses a device for improving the step coverage of metal film deposition, the device comprising: a cavity, in which a vacuum chamber is arranged, a target material placement position is arranged at the top of the cavity, and the target material placement position is used to place the target material; a wafer table, arranged at the bottom of the cavity, the wafer table is used to place the wafer, and the target material is sputtered onto the surface of the wafer under a preset process; wherein the height of the cavity is any value between 90 and 200 mm to increase the distance between the target material and the wafer.

[0005] CN115161594A discloses a coating device and method for improving deep hole filling. The device includes: a cavity, a target material carrier plate, a magnetron assembly, a base and a corrector; the target material carrier plate is located at the top of the cavity and is used to fix the target material, the target material is electrically connected to a first pulse power supply, and the first pulse power supply provides positive and negative asymmetric bipolar pulses; the magnetron assembly is located above the target material carrier plate, the base is located in the cavity, the corrector is located in the cavity and between the target material and the base, the corrector is spaced from the base and insulated from the cavity, the corrector is electrically connected to the positive pole of an external power supply to apply a positive bias, the corrector includes a plurality of correction units arranged at intervals, each correction unit is a through-hole structure that penetrates from top to bottom, and the corrector is used to correct the inclination angle of the target cation movement direction.

[0006] The above solution improves the step coverage and thus the hole filling efficiency by changing the equipment, but the equipment has the problem of complex composition or the improvement effect is not obvious. As the aspect ratio increases, how to reduce the spikes of aluminum hole filling is crucial to improving the stability and yield of the device. Summary of the invention

[0007] The purpose of the present invention is to provide a method and a sputtering device for thermal aluminum hole filling. The present invention uses a sputtering device containing a collimator in a standard cavity to sputter a titanium layer and a titanium nitride layer, thereby improving the step coverage of the connecting layer and the metal layer and improving the spike problem of aluminum hole filling.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for hot aluminum hole filling, the method comprising the following steps:

[0010] (1) Sputtering a titanium adhesion layer film on the side and bottom surfaces of the hole to be filled in the structure sheet containing the hole to be filled.

[0011] (2) Sputtering a titanium nitride barrier layer metal film on the surface of the titanium adhesion layer film to obtain a precursor structure sheet.

[0012] (3) After growing a cold aluminum seed layer on the surface of the titanium nitride barrier metal film of the precursor structure sheet, a hot aluminum layer is grown on the cold aluminum seed layer to complete the hole filling.

[0013] The sputtering in step (1) and step (2) uses a sputtering device with a collimator added in a standard cavity, and the collimator is arranged between the target material and the structural piece base in the standard cavity. During the sputtering process, the collimator intercepts the sputtering particles moving toward the wafer at a large angle, and allows the particles leaving the metal target material at an angle close to perpendicular to the wafer to pass.

[0014] The structural wafer of the present invention is a conventional silicon wafer and / or a silicon carbide wafer.

[0015] The present invention arranges a collimator in a standard cavity of a sputtering device, and utilizes the collimator to improve the step coverage of a titanium adhesion layer film and a titanium nitride barrier layer metal film, thereby reducing the thickness of the titanium adhesion layer film and the titanium nitride barrier layer metal film, thereby achieving the purpose of better filling aluminum and solving the problem of spikes occurring during the aluminum hole filling process.

[0016] Preferably, the width of the holes in the hole-filled structure sheet in step (1) is 0.5 to 2 μm, for example, 0.5 μm, 0.8 μm, 1 μm, 1.5 μm or 2 μm, etc., and is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0017] Preferably, the aspect ratio of the holes in the hole-filled structure sheet in step (1) is (0.8-2):1, for example: 0.8:1, 0.9:1, 1:1, 1.5:1 or 2:1, etc., and is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the structural sheet containing the holes to be filled is pretreated before the sputtering in step (1).

[0019] Preferably, the pretreatment includes degassing and pre-cleaning treatment.

[0020] Preferably, the degassing temperature is 400-450°C, for example, 400°C, 410°C, 420°C, 440°C or 450°C, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0021] Preferably, the cleaning thickness of the pre-cleaning treatment is 100 to 200 angstroms, for example, 100 angstroms, 120 angstroms, 150 angstroms, 180 angstroms or 200 angstroms, etc., and is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0022] Preferably, the sputtering atmosphere in step (1) includes argon.

[0023] Preferably, the flow rate of the argon gas is 40 to 60 sccm, for example, 40 sccm, 45 sccm, 50 sccm, 55 sccm or 60 sccm, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0024] Preferably, the sputtering power in step (1) is 3 to 8 kW, for example, 3 kW, 4 kW, 6 kW, 7 kW or 8 kW, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0025] Preferably, the ambient pressure of the sputtering in step (1) is 3 to 5 mtorr, for example, 3 mtorr, 3.5 mtorr, 4 mtorr, 4.5 mtorr or 5 mtorr, etc., and is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0026] Preferably, the thickness of the titanium adhesion layer film in step (1) is 50 to 400 angstroms, for example, 50 angstroms, 80 angstroms, 100 angstroms, 200 angstroms or 400 angstroms, etc., and is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0027] Preferably, the sputtering atmosphere in step (2) includes argon and nitrogen.

[0028] Preferably, the flow rate of the argon gas is 55-60 sccm, for example, 55 sccm, 56 sccm, 58 sccm, 59 sccm or 60 sccm, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] Preferably, the flow rate of the nitrogen gas is 90 to 95 sccm, for example, 90 sccm, 91 sccm, 92 sccm, 93 sccm, 94 sccm or 95 sccm, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] Preferably, the sputtering power in step (2) is 5 to 15 kW, for example, 5 kW, 8 kW, 10 kW, 12 kW or 15 kW, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0031] Preferably, the ambient pressure of the sputtering in step (2) is 6.5-7 mtorr, for example, 6.5 mtorr, 6.6 mtorr, 6.8 mtorr, 6.9 mtorr or 7 mtorr, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0032] Preferably, the thickness of the titanium nitride barrier metal film in step (2) is 650 to 1000 angstroms, for example, 650 angstroms, 700 angstroms, 800 angstroms, 900 angstroms or 1000 angstroms, etc., and is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0033] Preferably, the edge step coverage of the precursor structure sheet in step (2) is 35-60%, for example: 35%, 45%, 50%, 55% or 60%, etc., not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0034] Preferably, the bottom step coverage of the precursor structure sheet in step (2) is 70% to 90%, for example: 70%, 75%, 80%, 85% or 90%, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the atmosphere for growing the cold aluminum seed layer in step (3) includes argon.

[0036] Preferably, the flow rate of the argon gas is 40 to 60 sccm, for example, 40 sccm, 45 sccm, 50 sccm, 55 sccm or 60 sccm, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0037] Preferably, the atmosphere for growing the cold aluminum seed layer includes argon gas with a power of 3 to 5 kW, for example, 3 kW, 3.5 kW, 4 kW, 4.5 kW or 5 kW, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] Preferably, the ambient pressure for growing the cold aluminum seed layer in step (3) is 3.5 to 4 mtorr, for example, 3.5 mtorr, 3.6 mtorr, 3.8 mtorr, 3.9 mtorr or 4 mtorr, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] The method of the present invention can use high power and high pressure to fill holes during the process of filling the rear aluminum layer, which has greater practical significance.

[0040] Preferably, the temperature for growing the hot aluminum layer in step (3) is 400-460°C, for example, 400°C, 420°C, 440°C, 450°C or 460°C, etc., and is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] In a second aspect, the present invention provides a sputtering device, wherein the sputtering device is used for the method according to the first aspect;

[0042] A target material and a structural piece base are arranged in the standard cavity of the sputtering device, and a collimator is arranged between the target material and the structural piece base.

[0043] Preferably, the collimator is provided with honeycomb-shaped through holes.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The present invention arranges a collimator in a standard cavity of a sputtering device, and utilizes the collimator to improve the step coverage of a titanium adhesion layer film and a titanium nitride barrier layer metal film, thereby reducing the thickness of the titanium adhesion layer film and the titanium nitride barrier layer metal film, thereby achieving the purpose of better filling aluminum and solving the problem of spikes occurring during the aluminum hole filling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a focused ion beam electron microscope image of the holes in the precursor structure sheet described in Example 1.

[0047] Figure 2 It is a schematic structural diagram of a sputtering device used in an embodiment of the present invention, wherein 1 is a target material, 2 is a collimator, 3 is a structural sheet, and 4 is a structural sheet base.

[0048] Figure 3 It is a schematic diagram of the structure of a collimator used in a sputtering device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0050] The structural sheet of the present invention is pretreated before sputtering, and the pretreatment steps are as follows:

[0051] The structural sheet containing the holes to be filled is degassed at 425°C to remove moisture and organic residues in the holes to be filled, to prevent moisture and organic residues from affecting the subsequent growth of hot aluminum, and then pre-cleaned to a thickness of 160 angstroms.

[0052] The schematic diagram of the structure of the sputtering device used for hot aluminum hole filling in the embodiment is as follows: Figure 2 As shown, it includes a target material 1 and a structural piece base 4 , a collimator 2 is arranged between the target material 1 and the structural piece base 4 , and the sputtered ions are sputtered onto the structural piece 3 through the collimator 2 .

[0053] The structural schematic diagram of the collimator in the sputtering device is as follows: Figure 3 As shown, the collimator is provided with honeycomb-shaped through holes.

[0054] Example 1

[0055] This embodiment provides a method for hot aluminum hole filling, wherein a sputtering device with a collimator in a standard cavity is used, and the method comprises the following steps:

[0056] (1) A titanium adhesion layer film is sputtered on the side and bottom of the hole to be filled in a structure sheet with a hole width of 2 μm and an aspect ratio of 1:1. The sputtering atmosphere is argon gas, the argon gas flow rate is 50 sccm, the sputtering pressure is 4 mtorr, the power is 5 kW, and the thickness of the titanium adhesion layer film is 50 angstroms.

[0057] (2) In an atmosphere with an argon gas flow rate of 58 sccm and a nitrogen gas flow rate of 93 sccm, a titanium nitride barrier layer metal film was sputtered on the surface of the titanium adhesion layer film to obtain a precursor structure sheet. The sputtering pressure was 6.8 mtorr and the power was 10 kW. The thickness of the titanium nitride barrier layer metal film was 1000 angstroms. A focused ion beam electron microscope image of the pores in the precursor structure sheet was obtained as shown in FIG. Figure 1 As shown, Figure 1 It can be seen that the film thickness of the precursor structure sheet is: top: 322.8nm; bottom: 254.3nm; edge: 123.3nm. The step coverage of the film layer is obtained. The edge step coverage of the precursor structure sheet is 38.2%, and the bottom step coverage of the precursor structure sheet is 78.8%.

[0058] (3) After a cold aluminum seed layer is grown on the surface of the titanium nitride barrier metal film of the precursor structure sheet at a power of 4 kW and a pressure of 3.8 mtorr in an argon gas flow rate of 50 sccm, a hot aluminum layer is grown on the cold aluminum seed layer at 440°C to complete the hole filling.

[0059] The finished product of hot aluminum hole filling of the present invention has no sharp thorns in the hole, and in the finished product of hot aluminum hole filling of the present invention, the edge of the thin sheet of the hole can also be completely filled.

[0060] Example 2

[0061] This embodiment provides a method for hot aluminum hole filling, wherein a sputtering device with a collimator in a standard cavity is used, and the method comprises the following steps:

[0062] (1) A titanium adhesion layer film is sputtered on the side and bottom of the hole to be filled in a structure sheet with a hole width of 0.8 μm and an aspect ratio of 0.8:1. The sputtering atmosphere is argon gas with a flow rate of 40 sccm, a sputtering pressure of 3 mtorr, and a power of 3 kW. The thickness of the titanium adhesion layer film is 200 angstroms.

[0063] (2) In an atmosphere with an argon flow rate of 55 sccm and a nitrogen flow rate of 90 sccm, a titanium nitride barrier layer metal film is sputtered on the surface of the titanium adhesion layer film to obtain a precursor structure sheet. The sputtering pressure is 6.5 mtorr and the power is 5 kW. The thickness of the titanium nitride barrier layer metal film is 800 angstroms. The edge step coverage of the precursor structure sheet is 39.5%, and the bottom step coverage of the precursor structure sheet is 79.12%.

[0064] (3) In an atmosphere with an argon gas flow rate of 40 sccm, a cold aluminum seed layer is grown on the surface of the titanium nitride barrier metal film of the precursor structure sheet at a power of 3 kW and a pressure of 3.5 mtorr. Then, a hot aluminum layer is grown on the cold aluminum seed layer at 400°C to complete the hole filling.

[0065] Example 3

[0066] This embodiment provides a method for hot aluminum hole filling, wherein a sputtering device with a collimator in a standard cavity is used, and the method comprises the following steps:

[0067] (1) A titanium adhesion layer film is sputtered on the side and bottom of the hole to be filled in a structure sheet with a hole width of 1 μm and an aspect ratio of 1.2:1. The sputtering atmosphere is argon gas, the argon gas flow rate is 60 sccm, the sputtering pressure is 5 mtorr, the power is 8 kW, and the thickness of the titanium adhesion layer film is 400 angstroms.

[0068] (2) In an atmosphere with an argon flow rate of 60 sccm and a nitrogen flow rate of 95 sccm, a titanium nitride barrier layer metal film is sputtered on the surface of the titanium adhesion layer film to obtain a precursor structure sheet. The sputtering pressure is 7 mtorr and the power is 15 kW. The thickness of the titanium nitride barrier layer metal film is 650 angstroms. The edge step coverage of the precursor structure sheet is 40.25%, and the bottom step coverage of the precursor structure sheet is 79.85%.

[0069] (3) After a cold aluminum seed layer is grown on the surface of the titanium nitride barrier metal film of the precursor structure sheet at a power of 5 kW and a pressure of 4 mtorr in an argon gas flow rate of 60 sccm, a hot aluminum layer is grown on the cold aluminum seed layer at 460°C to complete the hole filling.

[0070] Example 4

[0071] The only difference between this embodiment and embodiment 1 is that the sputtering power in step (1) is 2 kW, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0072] Example 5

[0073] The only difference between this embodiment and embodiment 1 is that the sputtering power in step (1) is 10 kW, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0074] Example 6

[0075] The only difference between this embodiment and embodiment 1 is that the sputtering power in step (2) is 3 kW, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0076] Example 7

[0077] The only difference between this embodiment and embodiment 1 is that the sputtering power in step (2) is 20 kW, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0078] Example 8

[0079] The only difference between this embodiment and embodiment 1 is that the power for growing the cold aluminum seed layer in step (3) is 2 kW, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0080] Example 9

[0081] The only difference between this embodiment and embodiment 1 is that the power for growing the cold aluminum seed layer in step (3) is 6 kW, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0082] Example 10

[0083] The only difference between this embodiment and embodiment 1 is that the pressure for growing the cold aluminum seed layer in step (3) is 3 mtorr, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0084] Embodiment 11

[0085] The only difference between this embodiment and embodiment 1 is that the pressure of growing the cold aluminum seed layer in step (3) is 4.5 mtorr, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0086] Example 12

[0087] The only difference between this embodiment and embodiment 1 is that the argon gas flow rate for growing the cold aluminum seed layer in step (3) is 30 sccm, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0088] Example 13

[0089] The only difference between this embodiment and embodiment 1 is that the argon gas flow rate for growing the cold aluminum seed layer in step (3) is 70 sccm, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0090] Comparative Example 1

[0091] This comparative example adopts a conventional hot aluminum hole filling method, and the sputtering device, i.e., the standard cavity, does not contain a collimator. The hot aluminum hole filling method includes the following steps:

[0092] (1) A titanium adhesion layer film is sputtered on the side and bottom of the hole to be filled in a structure sheet with a hole width of 2 μm and an aspect ratio of 1:1. The sputtering atmosphere is argon gas, the argon gas flow rate is 50 sccm, the sputtering pressure is 4 mtorr, the power is 1 kW, and the thickness of the titanium adhesion layer film is 1000 angstroms.

[0093] (2) In an atmosphere with an argon flow rate of 30 sccm and a nitrogen flow rate of 49 sccm, a titanium nitride barrier layer metal film is sputtered on the surface of the titanium adhesion layer film to obtain a precursor structure sheet. The sputtering pressure is 5.6 mtorr, the power is 2 kW, the thickness of the titanium nitride barrier layer film is 3000 angstroms, and the edge step coverage of the precursor structure sheet is 48.6%. The bottom step coverage of the precursor structure sheet is 18.8%. The sputtering device without a collimator is prone to overhang and poor coverage at the corners.

[0094] (3) After a cold aluminum seed layer is grown on the surface of the titanium nitride barrier metal film of the precursor structure sheet at a power of 0.8 kW and a pressure of 1 mtorr in an argon gas flow rate of 20 sccm, a hot aluminum layer is grown on the cold aluminum seed layer at 440°C to complete the hole filling.

[0095] Performance Test:

[0096] Repeat the above embodiment and comparative example for ten groups of parallel tests to observe the occurrence of spikes. The observation results are shown in Table 1:

[0097] Table 1

[0098] Number of spikes / group Example 1 0 Example 2 0 Example 3 0 Example 4 3 Example 5 4 Example 6 4 Example 7 2 Example 8 0 Example 9 1 Example 10 0 Embodiment 11 1 Example 12 3 Example 13 2 Comparative Example 1 10

[0099] It can be seen from Table 1 that:

[0100] It can be seen from Examples 1-13 that the method for hot aluminum hole filling of the present invention can significantly reduce the problem of spikes generated during the hot aluminum hole filling process.

[0101] By comparing Example 1 with Examples 4-5, it can be seen that in the process of hot aluminum hole filling described in the present invention, the power of the sputtering titanium layer in step (1) will affect the hole filling effect. Controlling the power of the sputtering titanium layer to 3-8 kW can significantly improve the hole filling effect, while ensuring the adhesion, uniformity and density of the titanium adhesion layer film, increasing its coverage, thereby improving the stability of the subsequent sputtered titanium nitride barrier layer metal film and reducing the generation of spikes.

[0102] By comparing Example 1 with Examples 6-7, it can be seen that in the process of hot aluminum hole filling described in the present invention, the power of sputtering the titanium nitride layer in step (2) will affect the hole filling effect. Controlling the power of sputtering the titanium nitride layer to 5-15 kW can significantly improve the hole filling effect. While improving the uniformity and density of the titanium nitride layer and ensuring its blocking effect, the problem of spikes occurring in the subsequent aluminum hole filling process can be improved.

[0103] By comparing Example 1 with Examples 8-11, it can be seen that in the process of hot aluminum hole filling described in the present invention, the power of growing the cold aluminum seed layer in step (3) will affect the hole filling effect. Controlling the power of growing the cold aluminum seed layer to 3-5 kW and the pressure to 3.5-4 mtorr can significantly improve the hole filling effect. In the process of growing the cold aluminum seed layer, the present invention can use high power and high pressure for hole filling and try to avoid the problem of spikes. Compared with conventional low-power and low-pressure hole filling (0.8 kW and about 1 mtorr), the actual use significance is greater.

[0104] By comparing Example 1 with Examples 12-13, it can be seen that in the process of hot aluminum hole filling described in the present invention, the flow rate of the argon gas for growing the cold aluminum seed layer in step (3) will affect the hole filling effect. Controlling the flow rate of the argon gas for growing the cold aluminum seed layer at 40-60 sccm can significantly improve the hole filling effect, and controlling the sputtering ambient pressure within a suitable range can avoid oxidation and improve the density of the aluminum layer while ensuring a better filling effect while ensuring the mean free path.

[0105] By comparing Example 1 and Comparative Example 1, it can be seen that after the sputtering of titanium and titanium nitride by a conventional sputtering device, the filling of the subsequent aluminum layer must be done slowly at low power and low pressure, which takes a long time and has a low WPH. The present invention arranges a collimator in the standard cavity of the sputtering device, and improves the step coverage of the titanium adhesion layer film and the titanium nitride barrier layer metal film through the collimator, thereby reducing the thickness of the titanium adhesion layer film and the titanium nitride barrier layer metal film, thereby achieving the purpose of better filling of aluminum and improving the spike problem that occurs during the aluminum filling process. In the process of filling the subsequent aluminum layer, high power and high pressure can be used to fill the holes, which has greater practical significance.

[0106] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for hot aluminum hole filling, characterized in that: The method comprises the following steps: (1) sputtering a titanium adhesion layer film on the side and bottom surface of the hole to be filled of the structure sheet containing the hole to be filled; (2) sputtering a titanium nitride barrier layer metal film on the surface of the titanium adhesion layer film to obtain a precursor structure sheet; (3) After growing a cold aluminum seed layer on the surface of the titanium nitride barrier metal film of the precursor structure sheet, a hot aluminum layer is grown on the cold aluminum seed layer to complete the hole filling; Wherein, the sputtering in step (1) and step (2) uses a sputtering device with a collimator added in a standard cavity, and the collimator is arranged between the target material and the structural piece base in the standard cavity; The sputtering atmosphere in step (1) comprises argon gas, and the flow rate of the argon gas is 40 to 60 sccm; The sputtering power of step (1) is 3-8 kW, and the sputtering environment pressure is 3-5 mtorr; The sputtering atmosphere in step (2) comprises argon and nitrogen, the flow rate of the argon is 55-60 sccm, and the flow rate of the nitrogen is 90-95 sccm; The sputtering power of step (2) is 5-15 kW, and the sputtering environment pressure is 6.5-7 mtorr.

2. The method according to claim 1, characterized in that The width of the holes in the hole-filled structure sheet in step (1) is 0.5 to 2 μm; The aspect ratio of the holes in the hole-filled structure sheet in step (1) is (0.8-2):

1.

3. The method according to claim 1, characterized in that The thickness of the titanium adhesion layer film in step (1) is 50 to 400 angstroms.

4. The method according to claim 1, characterized in that The thickness of the titanium nitride barrier metal film in step (2) is 650 to 1000 angstroms.

5. The method according to claim 1, characterized in that The edge step coverage of the precursor structure sheet in step (2) is 35-60%; In step (2), the bottom step coverage of the precursor structure sheet is 70-90%.

6. The method according to claim 1, characterized in that The atmosphere for growing the cold aluminum seed layer in step (3) includes argon gas, and the flow rate of the argon gas is 40 to 60 sccm; In step (3), the power for growing the cold aluminum seed layer is 3-5 kW, and the ambient pressure for growing the cold aluminum seed layer is 3.5-4 mtorr.

7. The method according to claim 1, characterized in that The temperature of growing the hot aluminum layer in step (3) is 400-460°C.

8. A sputtering device, characterized in that: The sputtering device is used for the method according to any one of claims 1 to 7; A target material and a structural piece base are arranged in a standard cavity of the sputtering device, and a collimator is arranged between the target material and the structural piece base; The collimator is provided with honeycomb-shaped through holes.

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