Physical vapor deposition method and physical vapor deposition device

Abstract

The invention relates to a physical vapor deposition method and a physical vapor deposition device, in particular to the technical field of physical vapor deposition, and the method comprises the steps that a deposition chamber is vacuumized, and then a workpiece to be treated is sequentially subjected to preheating operation, pre-deposition operation and deposition operation; wherein the flow of gas sprayed to the front surface of the workpiece is controlled to be greater than that of gas sprayed to the back surface of the workpiece in the deposition operation; and the ratio of the flow of the gas sprayed to the reverse side of the workpiece to the flow of the gas sprayed to the front side of the workpiece is (0.1-0.8): 1. According to the physical vapor deposition method provided by the invention, the temperature difference amplitude of the center and the edge of the workpiece in the physical vapor deposition process can be reduced by controlling the flow of the gas sprayed to the front surface and the back surface of the workpiece in the deposition operation process, so that the lattice size difference of the workpiece is improved, the lattice size uniformity is improved, and the product yield is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of physical vapor deposition, and in particular to a physical vapor deposition method and a physical vapor deposition device. Background Art

[0002] At present, in the preparation process of semiconductor components, the front-end process often uses physical vapor deposition technology to deposit a metal material film on the surface of the wafer. The formed front-end intermediate is cut into multiple lattices in the back-end process for further use in the preparation of functional semiconductor components.

[0003] Especially for the manufacture of power devices, multiple etching units are usually formed on the surface of the wafer. After being processed by the physical vapor deposition process, multiple film-coated lattice units are formed to facilitate subsequent process cutting. However, the front-end intermediates prepared by the existing physical vapor deposition process have the problem of uneven lattice size, which leads to huge differences in the performance of semiconductor components and affects the yield rate. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a physical vapor deposition method and a physical vapor deposition device to solve the problem that the lattice size of the workpiece obtained by the physical vapor deposition process is uneven, which affects the product yield.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a physical vapor deposition method, the method comprising:

[0007] The deposition chamber is evacuated, and then the workpiece to be processed is subjected to preheating operation, pre-deposition operation and deposition operation in sequence;

[0008] Among them, in the deposition operation, the gas flow rate sprayed toward the front side of the workpiece is controlled to be greater than the gas flow rate sprayed toward the back side of the workpiece; the ratio of the gas flow rate sprayed toward the back side of the workpiece to the gas flow rate at the front side of the workpiece is (0.1-0.8):1.

[0009] The physical vapor deposition method provided by the present invention controls the gas flow rate sprayed toward the front and back surfaces of the workpiece during the deposition process with a ratio in the range of (0.1-0.8):1, thereby reducing the temperature difference between the center and the edge of the workpiece in the physical vapor deposition process, improving the uniformity of the workpiece surface temperature of the deposited film, thereby improving the lattice size difference of the workpiece and improving the uniformity of the lattice size.

[0010] As a preferred technical solution of the present invention, the gas flow rate sprayed toward the front of the workpiece is 20-35 sccm;

[0011] Preferably, the gas flow rate sprayed toward the reverse side of the workpiece is 5-15 sccm.

[0012] As a preferred technical solution of the present invention, the vacuuming is performed so that the vacuum degree of the deposition chamber is 10 -10 -10 - 5 torr.

[0013] As a preferred technical solution of the present invention, the preheating operation is to preheat the workpiece using airflow.

[0014] As a preferred technical solution of the present invention, the preheating operation is to preheat the workpiece to 200-300° C. As a preferred technical solution of the present invention, the gas flow rate for providing ionized ions to form a bombardment source in the pre-deposition operation is 10-30 sccm.

[0015] As a preferred technical solution of the present invention, the operating power of the pre-deposition operation is 500-1500W.

[0016] As a preferred technical solution of the present invention, the time of the pre-deposition operation is 1-10s.

[0017] As a preferred technical solution of the present invention, the operating power of the deposition operation is 10-15kW.

[0018] In a second aspect, the present invention provides a physical vapor deposition device using the method described in the first aspect, the physical vapor deposition device comprising:

[0019] At least two deposition chambers are distributed in a ring shape; the deposition chambers are connected to the transmission chamber;

[0020] Each of the deposition chambers is provided with a fixing seat for fixing the target material;

[0021] and a supporting base opposite to the target;

[0022] Each of the deposition chambers is respectively connected to a first air supply device, a second air supply device and an air extraction device, and the target material is electrically connected to a DC magnetron device.

[0023] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0024] The method provided by the present invention can improve the temperature difference amplitude of the workpiece, such as the center and edge of the wafer, reduce the deformation difference between the center and edge of the wafer, improve the uniformity of thin film deposition at the center and edge of the wafer, and further improve the lattice size difference between the center and edge after cutting, improve the uniformity of the lattice size, and improve the product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a process flow chart of the physical vapor deposition method of the present invention;

[0026] Figure 2 It is a partial structural schematic diagram of the physical vapor deposition device of the present invention;

[0027] Figure 3 It is a schematic structural diagram of a deposition chamber in a physical vapor deposition device of the present invention;

[0028] Figure 4 Schematic diagram of the distribution of test points of the present invention.

[0029] In the figure: 1-deposition chamber, 2-pretreatment chamber, 3-degassing chamber, 4-transmission chamber, 1.1-target material, 1.2-wafer, 1.3-DC magnetron device, 1.4-carrying base, 1.5-first gas supply device, 1.6-second gas supply device, 1.7-exhaust device;

[0030] A1-first detection point, A2-second detection point, A3-third detection point, A4-fourth detection point, A5-fifth detection point.

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0032] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0033] This embodiment provides a physical vapor deposition method, such as Figure 1 As shown, the method includes:

[0034] The deposition chamber is evacuated, and then the workpiece to be processed is subjected to preheating operation, pre-deposition operation and deposition operation in sequence;

[0035] Among them, in the deposition operation, the gas flow rate sprayed toward the front side of the workpiece is controlled to be greater than the gas flow rate sprayed toward the back side of the workpiece; the ratio of the gas flow rate sprayed toward the back side of the workpiece to the gas flow rate at the front side of the workpiece is (0.1-0.8):1, for example, it can be 0.1:1, 0.25:1, 0.37:1, 0.43:1, 0.5:1, 0.59:1, 0.61:1, 0.72:1 or 0.8:1, etc., but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0036] In the present invention, the gases used in the gas flow used in the preheating operation, the pre-deposition operation and the deposition operation include gases commonly used in the art such as argon, nitrogen and the like which do not affect the film forming performance.

[0037] In the present invention, when the deposition chamber is evacuated, the workpiece to be processed has been loaded into the chamber so that the subsequent processing process can be carried out continuously.

[0038] In the present invention, the workpiece to be processed includes a silicon-containing substrate, such as a wafer, that needs to be subjected to physical vapor deposition to form a film layer.

[0039] In the present invention, the front and back sides of the workpiece are exemplarily described as follows. For example, for a wafer to be deposited, the front side is the deposited film layer of the workpiece to be processed in the present invention, and the back side is the back side of the workpiece, that is, the side not involved in the deposited film layer.

[0040] In the present invention, the temperature field distribution of the workpiece during the deposition operation is adjusted by controlling the gas flow rate sprayed toward the front side and the gas flow rate sprayed toward the back side, thereby reducing the temperature difference between the center and the edge of the workpiece, thereby improving the uniformity of the lattice size, especially the uniformity of the size of the coating lattice unit.

[0041] Specifically, the gas flow rate sprayed toward the front side of the workpiece is 20-35 sccm, for example, it can be 20 sccm, 21 sccm, 22 sccm, 23 sccm, 24 sccm, 25 sccm, 26 sccm, 27 sccm, 28 sccm, 29 sccm, 30 sccm, 31 sccm, 32 sccm, 33 sccm, 34 sccm or 35 sccm, etc., but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0042] Specifically, the gas flow rate sprayed onto the back surface of the workpiece is 5-15sccm, for example, it can be 5sccm, 6sccm, 7sccm, 8sccm, 9sccm, 10sccm, 11sccm, 12sccm, 13sccm, 14sccm or 15sccm, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0043] Specifically, the vacuum pumping makes the vacuum degree of the deposition chamber to be 10 -10 -10 -5 torr, for example, can be 10 - 10 torr, 10 -9 torr, 10 -8 torr, 10 -7 torr, 10 -6 torr or 10 -5torr, etc., but not limited to the listed values, and other values ​​not listed in the range also meet the requirements.

[0044] In the present invention, the vacuum degree controlled during vacuuming is an absolute vacuum degree.

[0045] Specifically, the preheating operation is to preheat the workpiece to be processed by using airflow.

[0046] The flow rate of the gas flow used in the preheating operation, that is, the gas flow rate of argon, is 10-30sccm, for example, it can be 10sccm, 12sccm, 14sccm, 16sccm, 18sccm, 20sccm, 22sccm, 24sccm, 26sccm, 28sccm or 30sccm, etc., but is not limited to the listed values. Other values ​​not listed in this range also meet the requirements.

[0047] Specifically, the preheating operation is to preheat the workpiece to be processed to 200-300°C, for example, it can be 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C or 300°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0048] The pre-deposition operation is to use ionized ions to bombard the target material and then pre-deposit the workpiece. The ionized ions are generated by ionizing the gas. For example, a DC magnetron device is used to discharge to the deposition chamber, and the argon gas entering the deposition chamber is ionized to generate argon ions. At this time, the gas flow rate that provides the ionized ions to form a bombardment source is the argon gas flow rate, and the ionized ions are argon ions.

[0049] Specifically, the gas flow rate for providing ionized ions to form a bombardment source in the pre-deposition operation is 10-30sccm, for example, it can be 10sccm, 12sccm, 14sccm, 16sccm, 18sccm, 20sccm, 22sccm, 24sccm, 26sccm, 28sccm or 30sccm, but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0050] Specifically, the operating power of the pre-deposition operation is 500-1500W, for example, it can be 500W, 600W, 700W, 800W, 900W, 1000W, 1100W, 1200W, 1300W, 1400W or 1500W, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0051] Specifically, the time of the pre-deposition operation is 1-10s, for example, it can be 1s, 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s or 10s, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0052] Specifically, the operating power of the deposition operation is 10-15kW, for example, it can be 10kW, 10.5kW, 11kW, 11.5kW, 12kW, 12.5kW, 13kW, 13.5kW, 14kW, 14.5kW or 15kW, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0053] In the present invention, the temperature of the chamber during the deposition operation is 200-300°C, for example, it can be 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C or 300°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0054] In the present invention, the time of the deposition operation is selected according to the thickness of the film layer obtained by deposition, and the present invention does not make any specific requirements.

[0055] In the present invention, after the deposition operation is completed, the introduction of argon gas into the chamber is stopped, and after the workpiece is transferred out of the deposition chamber, a vacuum operation is performed again, and the gas in the deposition chamber is extracted by a vacuum device to restore the deposition chamber to a vacuum state, thereby maintaining the vacuum state of the deposition chamber and providing a vacuum process environment for the next deposition operation.

[0056] The present invention also provides a physical vapor deposition device, such as Figure 2 and Figure 3As shown, it includes: at least two deposition chambers 1 distributed in a ring shape, which can simultaneously perform physical vapor deposition processes on multiple workpieces to improve production capacity. The deposition chamber 1 is connected to the transfer chamber 4, and the transfer chamber 4 is also connected to the pretreatment chamber 2 and the degassing chamber 3 respectively. Before the workpiece to be processed, such as the wafer 1.2 to be processed, enters the deposition chamber 1, the wafer 1.2 can be pretreated through the pretreatment chamber 2 to remove the oxide on the surface of the wafer, thereby ensuring the performance of the deposited film layer and improving the yield of the product; after the wafer 1.2 comes out of the deposition chamber 1, it can be post-processed through the degassing chamber 3 , to remove water vapor from the surface of the wafer 1.2; each deposition chamber 1 is provided with a fixing seat for fixing the target material 1.1, and a supporting base 1.4 for supporting the wafer 1.2 opposite to the target material 1.1, each deposition chamber 1 is respectively connected with a first gas supply device 1.5, a second gas supply device 1.6 and an exhaust device 1.7, the target material 1.1 is electrically connected to the DC magnetron device 1.3, the first gas supply device 1.5 and the second gas supply device 1.6 can be, for example, gas pipelines, the exhaust device 1.7 can be, for example, a vacuum pump, and the DC magnetron device 1.3 can be, for example, a DC power supply and a magnet.

[0057] In the present invention, the target material 1.1 can be reasonably selected according to the specific required deposited film layer, for example, a metal target material, a ceramic target material, etc. can be selected for sputtering deposition of the film layer, and the wafer can also be adaptively replaced with other workpieces to be deposited with the film layer.

[0058] Further, in order to illustrate the improvement effect that can be achieved by the physical vapor deposition method provided by the present invention, four deposition chambers are used to simultaneously process four workpieces at 265° C. The workpieces are thermocouple wafers, and the target material is an aluminum-copper target material. The actual example is described as follows:

[0059] This embodiment provides a physical vapor deposition method, the method comprising:

[0060] The deposition chamber is evacuated, and then the workpiece to be processed is subjected to preheating operation, pre-deposition operation and deposition operation in sequence;

[0061] In the deposition operation, the argon gas flow rate sprayed toward the front side of the workpiece (deposition film layer) is controlled to be greater than the argon gas flow rate sprayed toward the back side of the workpiece, and the ratio of the gas flow rate sprayed toward the back side of the workpiece to the gas flow rate toward the front side (deposition film layer) is (0.1-0.8):1;

[0062] The argon flow rate sprayed to the front side of the workpiece (deposition film layer) is 20-35sccm; the argon flow rate sprayed to the back side of the workpiece is 5-15sccm;

[0063] The vacuum degree of the deposition chamber was 10 -8 torr;

[0064] The preheating operation is to preheat the workpiece using argon gas flow; the preheating operation is to preheat the workpiece to be processed to 260±5℃;

[0065] The argon gas flow rate for providing ionized ions to form a bombardment source during the pre-deposition operation is 35±5sccm; the operating power of the pre-deposition operation is 500W±10%; the time of the pre-deposition operation is 4s;

[0066] The operating power for deposition operation is 9kW±10%.

[0067] The gas flow rates of the four deposition chambers sprayed toward the workpiece surface are as follows:

[0068] Comparative Example 1

[0069] During the deposition operation, the ratio of the gas flow rate sprayed toward the back side of the workpiece to the gas flow rate toward the front side of the workpiece (deposition film layer) was 0.075:1; the argon gas flow rate sprayed toward the front side of the workpiece (deposition film layer) was 20 sccm; and the argon gas flow rate sprayed toward the back side of the workpiece was 1.5 sccm.

[0070] Example 1

[0071] During the deposition operation, the ratio of the gas flow rate sprayed toward the back side of the workpiece to the gas flow rate toward the front side of the workpiece (deposition film layer) was 0.25:1; the argon gas flow rate sprayed toward the front side of the workpiece (deposition film layer) was 20 sccm; and the argon gas flow rate sprayed toward the back side of the workpiece was 5 sccm.

[0072] Example 2

[0073] During the deposition operation, the ratio of the gas flow rate sprayed toward the back side of the workpiece to the gas flow rate toward the front side of the workpiece (deposition film layer) was 0.5:1; the argon gas flow rate sprayed toward the front side of the workpiece (deposition film layer) was 20 sccm; and the argon gas flow rate sprayed toward the back side of the workpiece was 10 sccm.

[0074] Example 3

[0075] During the deposition operation, the ratio of the gas flow rate sprayed toward the back side of the workpiece to the gas flow rate toward the front side of the workpiece (deposition film layer) was 0.43:1; the argon gas flow rate sprayed toward the front side of the workpiece (deposition film layer) was 35 sccm; and the argon gas flow rate sprayed toward the back side of the workpiece was 15 sccm.

[0076] The temperature distribution of the center and edge surfaces of the workpiece processed by the physical vapor deposition method of the present invention is shown in Table 1.

[0077] Table 1

[0078]

[0079] In the table, the standard deviation uniformity U% (sigma) is calculated using the following formula:

[0080] In the formula, n is 5 and N is 5.

[0081] Amplitude difference uniformity range u% = range / (2×mean).

[0082] In the table, A1, A2, A3, A4, and A5 in the first row are test points. In this embodiment, the detection equipment uses a TP700 multi-channel data recorder to test and verify the thermocouple wafer. The five test points are selected as follows: the center of the thermocouple wafer is taken as the first detection point A1, and four points close to the edge of the wafer are taken as the second detection point A2, the third detection point A3, the fourth detection point A4, and the fifth detection point A5. The four detection points are distributed in a ring shape with the first detection point A1 as the center, and the center line of two opposite detection points passes through the first detection point A1 and forms a cross or X shape, such as Figure 4 As shown, for example, the line connecting the second detection point A2 and the fourth detection point A4 is L1, the line connecting the third detection point A3 and the fifth detection point A5 is L2, L1 and L2 pass through the first detection point A1 and L1 and L2 are in an X shape, and the specific detection point locations are determined according to the actual thermocouple wafer and detection equipment used.

[0083] It can be seen from Table 1 that compared with the existing physical vapor deposition process shown in Comparative Example 1, when preparing the front-end intermediate, the gas flow rate on the front and back sides of the wafer is usually not controlled, resulting in a temperature difference between the center and edge of the wafer and then the problem of uneven lattice size. In the scheme provided by the present invention, by controlling the gas flow rate sprayed to the front and back surfaces of the workpiece within a certain proportional range during the deposition operation, the temperature extreme difference between the center and the edge of the wafer can be effectively reduced, the temperature difference between the center and the edge of the wafer can be improved, the temperature uniformity between the center and the edge of the wafer can be improved, and the deformation difference between the center and the edge of the wafer can be reduced, thereby improving the uniformity of thin film deposition at the center and the edge of the wafer, and then improving the lattice size difference between the center and the edge after cutting, improving the uniformity of the lattice size, and ensuring the yield of the product.

[0084] It is stated that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0085] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0086] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0087] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A physical vapor deposition method, characterized in that: The method comprises: The deposition chamber is evacuated, and then the workpiece to be processed is subjected to preheating operation, pre-deposition operation and deposition operation in sequence; Among them, in the deposition operation, the gas flow rate sprayed toward the front side of the workpiece is controlled to be greater than the gas flow rate sprayed toward the back side of the workpiece; the ratio of the gas flow rate sprayed toward the back side of the workpiece to the gas flow rate at the front side of the workpiece is (0.1-0.8):

1.

2. The method according to claim 1, characterized in that: The gas flow rate sprayed toward the front of the workpiece is 20-35 sccm; The gas flow rate sprayed toward the reverse side of the workpiece is 5-15 sccm.

3. The method according to claim 1 or 2, characterized in that: The vacuum pumping makes the vacuum degree of the deposition chamber to be 10 -10 -10 -5 torr.

4. The method according to any one of claims 1 to 3, characterized in that: The preheating operation is to preheat the workpiece by using airflow.

5. The method according to any one of claims 1 to 4, characterized in that: The preheating operation is to preheat the workpiece to 200-300°C.

6. The method according to any one of claims 1 to 5, characterized in that: The gas flow rate for providing ionized ions to form a bombardment source in the pre-deposition operation is 10-30 sccm.

7. The method according to any one of claims 1 to 6, characterized in that: The operating power of the pre-deposition operation is 500-1500W.

8. The method according to any one of claims 1 to 7, characterized in that: The time of the pre-deposition operation is 1-10s.

9. The method according to any one of claims 1 to 8, characterized in that: The operating power of the deposition operation is 10-15 kW.

10. A physical vapor deposition device using the method according to any one of claims 1 to 9, characterized in that: The physical vapor deposition device comprises: At least two deposition chambers are distributed in a ring shape; the deposition chambers are connected to the transmission chamber; Each of the deposition chambers is provided with a fixing seat for fixing the target material; and a supporting base opposite to the target; Each of the deposition chambers is respectively connected to a first air supply device, a second air supply device and an air extraction device, and the target material is electrically connected to a DC magnetron device.

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