A physical vapor deposition method and a physical vapor deposition apparatus

Abstract

The present invention relates to a physical vapor deposition method and a physical vapor deposition apparatus, and specifically relates to the technical field of physical vapor deposition. The method includes: evacuating the deposition chamber, and then sequentially performing a preheating operation, a pre-deposition operation, and a deposition operation on the workpiece to be processed; wherein, in the deposition operation, the gas flow rate sprayed onto the front surface of the workpiece is controlled to be greater than the gas flow rate sprayed onto the back surface of the workpiece; the ratio of the gas flow rate sprayed onto the back surface of the workpiece to the gas flow rate on the front surface of the workpiece is (0.1-0.8):1. The physical vapor deposition method provided by the present invention can reduce the temperature difference amplitude between the center and the edge of the workpiece in the physical vapor deposition process by controlling the gas flow rates sprayed onto the front and back surfaces of the workpiece, thereby improving the lattice size difference of the workpiece, enhancing the uniformity of the lattice size, and ensuring the yield of the product.

Description

Technical Field

[0001] The present invention relates to the technical field of physical vapor deposition, and particularly relates to a physical vapor deposition method and a physical vapor deposition apparatus. Background Art

[0002] Currently, in the process of manufacturing semiconductor components, in the front-end process, a physical vapor deposition process is often used to deposit a metal material thin film on the surface of a wafer. The formed front-end intermediate is cut into multiple lattices in the back-end process for further manufacturing functional semiconductor components.

[0003] Especially for the manufacturing 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 coated lattice units are formed to facilitate the cutting in the back-end process. However, the front-end intermediate prepared by the existing physical vapor deposition process has the problem of uneven lattice size, resulting in a huge difference in the performance of semiconductor components and affecting 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 apparatus to solve the problem of uneven lattice size of the workpiece obtained by the physical vapor deposition process and affecting the product yield rate.

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

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

[0007] Vacuum the deposition chamber, and then perform a preheating operation, a pre-deposition operation, and a deposition operation on the workpiece to be processed in sequence;

[0008] Wherein, in the deposition operation, the gas flow rate sprayed onto the front surface of the workpiece is controlled to be greater than the gas flow rate sprayed onto the back surface of the workpiece; the ratio of the gas flow rate sprayed onto the back surface of the workpiece to the gas flow rate on the front surface of the workpiece is (0.1 - 0.8):1.

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

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

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

[0012] As a preferred technical solution of the present invention, the evacuation makes the vacuum degree of the deposition chamber 10 -10 -10 - 5 torr.

[0013] As a preferred technical solution of the present invention, the preheating operation is to preheat the workpiece by means of air flow.

[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 ionization 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 operation power of the pre - deposition operation is 500 - 1500 W.

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

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

[0018] In a second aspect, the present invention provides a physical vapor deposition apparatus using the method described in the first aspect. The physical vapor deposition apparatus includes:

[0019] At least two deposition chambers distributed in a ring; the deposition chambers are communicated with a transfer chamber;

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

[0021] And a carrying base opposite to the target;

[0022] Each of the deposition chambers is respectively connected with a first gas supply device, a second gas supply device and a pumping device, and the target 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 workpiece by controlling the gas flow rates sprayed onto the front and back surfaces of the workpiece during the deposition operation. For example, it can reduce the temperature difference amplitude between the center and the edge of the wafer, reduce the deformation difference between the center and the edge of the wafer, improve the uniformity of thin - film deposition between the center and the edge of the wafer, and further improve the lattice size difference between the center and the edge after cutting, improve the uniformity of lattice size, and improve the product yield. Description of the Drawings

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

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

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

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

[0029] In the figure: 1 - deposition chamber, 2 - pretreatment chamber, 3 - degassing chamber, 4 - transfer chamber, 1.1 - target, 1.2 - wafer, 1.3 - DC magnetron device, 1.4 - carrier base, 1.5 - first gas supply device, 1.6 - second gas supply device, 1.7 - pumping 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 will be further described in detail below with reference to the accompanying drawings. However, the following examples are merely simple examples of the present invention and do not represent or limit the scope of the claimed protection of the present invention. The scope of protection of the present invention shall be subject to the claims. Specific Embodiments

[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, as Figure 1 shown, the method includes:

[0034] Vacuum the deposition chamber, and then perform pre - heating operation, pre - deposition operation and deposition operation on the workpiece to be processed in sequence;

[0035] Among them, in the deposition operation, control the gas flow rate sprayed on the front side of the workpiece to be greater than the gas flow rate sprayed on the back side of the workpiece; the ratio of the gas flow rate sprayed on the back side of the workpiece to the gas flow rate on 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 not limited to the listed values. Other unlisted values within this range also meet the requirements.

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

[0037] In the present invention, when evacuating the deposition chamber, the workpiece to be processed has been loaded into the chamber to facilitate the continuous progress of the subsequent processing.

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

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

[0040] In the present invention, by controlling the gas flow rate sprayed onto the front side and the back side of the workpiece, the temperature field distribution of the workpiece during the deposition operation is adjusted, the temperature difference amplitude between the center and the edge of the workpiece is reduced, and thus the uniformity of the lattice size is improved, especially the uniformity of the size of the film-covered lattice units.

[0041] Specifically, the gas flow rate sprayed onto 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 not limited to the listed values. Other unlisted values within this range also meet the requirements.

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

[0043] Specifically, the evacuation makes the vacuum degree of the deposition chamber 10 -10 -10 -5 torr. For example, it can be 10 - 10 torr, 10 -9 torr, 10 -8 torr, 10 -7 torr, 10 -6 torr, or 10 -5such as torr, but not limited to the listed values, and other unlisted values within this range also meet the requirements.

[0044] In the present invention, the degree of vacuum controlled during vacuum pumping is the absolute degree of vacuum.

[0045] Specifically, the preheating operation is to preheat the workpiece to be processed by means of an air flow.

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

[0047] Specifically, the workpiece to be processed is preheated to 200 - 300 °C in the preheating operation. 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, etc., but not limited to the listed values, and other unlisted values within this range also meet the requirements.

[0048] The pre - deposition operation is to bombard the target with ionized ions to pre - deposit on the workpiece. The ionized ions are generated by the ionization of a gas. For example, by discharging to the deposition chamber through a DC magnetron device, the argon gas introduced into the deposition chamber is ionized to generate argon ions. At this time, the gas flow rate providing the ionized ions to form the bombardment source is the argon gas flow rate, and the ionized ions are argon ions.

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

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

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

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

[0054] In the present invention, the time of the deposition operation is selected according to the thickness of the deposited film layer, and no specific requirements are made in the present invention.

[0055] In the present invention, after the deposition operation, the supply of argon gas to the chamber is stopped. And after the workpiece is transferred out of the deposition chamber, a re-evacuation operation is performed to extract the gas in the deposition chamber through the pumping device, so that the deposition chamber returns to the 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 in the figure, it includes: at least two deposition chambers 1 distributed in a ring shape, enabling physical vapor deposition processes for multiple workpieces simultaneously to improve production capacity. The deposition chambers 1 are connected to a transfer chamber 4, and the transfer chamber 4 is also respectively connected to a pretreatment chamber 2 and a degassing chamber 3. 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 wafer surface, ensuring the performance of the deposited film layer and improving the yield of the product. After the wafer 1.2 exits the deposition chamber 1, post-treatment can be carried out through the degassing chamber 3 to remove the water vapor on the wafer 1.2 surface. Each deposition chamber 1 is provided with a fixing seat for fixing the target 1.1 and a carrier base 1.4 for carrying the wafer 1.2 opposite to the target 1.1. Each deposition chamber 1 is respectively connected to a first gas supply device 1.5, a second gas supply device 1.6, and an evacuation device 1.7. The target 1.1 is electrically connected to a 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, and the evacuation device 1.7 can be, for example, a vacuum pump. The DC magnetron device 1.3 can be, for example, a DC power supply and a magnet.

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

[0058] Furthermore, in order to illustrate the improvement effects that can be achieved by the physical vapor deposition method provided by the present invention, an actual example of using four deposition chambers to simultaneously process four workpieces at 265 °C is given. The workpieces use thermocouple wafers, and the target uses an aluminum-copper target, which is specifically as follows:

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

[0060] Evacuate the deposition chamber, and then perform preheating operation, pre-deposition operation, and deposition operation on the workpiece to be processed in sequence;

[0061] Among them, during the deposition operation, control the argon gas flow rate sprayed onto the front surface (deposited film surface) of the workpiece to be greater than the argon gas flow rate sprayed onto the back surface of the workpiece. The ratio of the gas flow rate sprayed onto the back surface of the workpiece to the gas flow rate on the front surface (deposited film surface) is (0.1 - 0.8):1;

[0062] The argon gas flow rate sprayed onto the front surface (deposited film surface) of the workpiece is 20 - 35 sccm; the argon gas flow rate sprayed onto the back surface of the workpiece is 5 - 15 sccm;

[0063] Evacuate to make the vacuum degree of the deposition chamber 10 -8 torr;

[0064] The preheating operation is to preheat the workpiece with an argon gas flow; the preheating operation is to preheat the workpiece to be processed to 260 ± 5 °C;

[0065] In the pre-deposition operation, the argon gas flow rate providing the ionization ions to form the bombardment source is 35 ± 5 sccm; the operation power of the pre-deposition operation is 500 W ± 10%; the time of the pre-deposition operation is 4 s;

[0066] The operation power of the deposition operation is 9 kW ± 10%.

[0067] Among them, the gas flow rates of the four deposition chambers spraying onto the surface of the workpiece are as follows:

[0068] Comparative Example 1

[0069] In the deposition operation, the ratio of the gas flow rate spraying onto the reverse side of the workpiece to the gas flow rate on the front side (deposited film layer) of the workpiece is 0.075:1; the argon gas flow rate spraying onto the front side (deposited film layer) of the workpiece is 20 sccm; the argon gas flow rate spraying onto the reverse side of the workpiece is 1.5 sccm.

[0070] Example 1

[0071] In the deposition operation, the ratio of the gas flow rate spraying onto the reverse side of the workpiece to the gas flow rate on the front side (deposited film layer) of the workpiece is 0.25:1; the argon gas flow rate spraying onto the front side (deposited film layer) of the workpiece is 20 sccm; the argon gas flow rate spraying onto the reverse side of the workpiece is 5 sccm.

[0072] Example 2

[0073] In the deposition operation, the ratio of the gas flow rate spraying onto the reverse side of the workpiece to the gas flow rate on the front side (deposited film layer) of the workpiece is 0.5:1; the argon gas flow rate spraying onto the front side (deposited film layer) of the workpiece is 20 sccm; the argon gas flow rate spraying onto the reverse side of the workpiece is 10 sccm.

[0074] Example 3

[0075] In the deposition operation, the ratio of the gas flow rate spraying onto the reverse side of the workpiece to the gas flow rate on the front side (deposited film layer) of the workpiece is 0.43:1; the argon gas flow rate spraying onto the front side (deposited film layer) of the workpiece is 35 sccm; the argon gas flow rate spraying onto the reverse side of the workpiece is 15 sccm.

[0076] For the temperature distribution on the center and edge surfaces of the workpiece processed by the physical vapor deposition method of the present invention, see Table 1 in detail.

[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 value).

[0082] In the table, A1, A2, A3, A4, and A5 in the first row are test points. In this embodiment, the detection device uses a TP700 multi-channel data recorder to test and verify the thermocouple wafer. The selection method for the five test points is as follows: taking the center of the thermocouple wafer as the first detection point A1, and taking four points near the edge of the wafer 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 circularly distributed with the first detection point A1 as the center, and the center connection lines of the two pairs of opposite detection points pass through the first detection point A1 and form a cross or an X shape, as Figure 4 shown. For example, the connection line between the second detection point A2 and the fourth detection point A4 is L1, and the connection line between 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 form an X shape. The specific location of the detection points is determined according to the actually used thermocouple wafer and the detection device.

[0083] As can be seen from Table 1, compared with the prior physical vapor deposition process shown in Comparative Example 1, when preparing the front-end intermediate, the gas flow rates on the front and back surfaces of the wafer are usually not controlled, resulting in a temperature difference between the center and the edge of the wafer and further causing the problem of non-uniform lattice size. In the solution provided by the present invention, by controlling the gas flow rates sprayed on the two surfaces of the workpiece, the front and the back, within a certain proportion range during the deposition operation, the temperature range difference between the center and the edge of the wafer can be effectively reduced, the temperature difference amplitude 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 increased, the deformation difference between the center and the edge of the wafer can be reduced, thereby improving the uniformity of thin film deposition between the center and the edge of the wafer, and further improving the lattice size difference between the center and the edge after cutting, increasing the uniformity of the lattice size, and ensuring the yield of the product.

[0084] It is declared that the present invention uses the above embodiments to illustrate the detailed structural features of the present invention, 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 to the present invention, the equivalent replacement of the components selected by the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

[0085] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0086] In addition, it should be noted that, among the various specific technical features described in the above specific embodiments, they can be combined in any appropriate manner without conflict. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0087] Furthermore, any combination can be made among various different embodiments of the present invention, as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A physical vapor deposition method, characterized in that, The method includes: Evacuating the deposition chamber, and then successively performing a preheating operation, a pre-deposition operation, and a deposition operation on the workpiece to be processed; Among them, in the deposition operation, the gas flow rate sprayed onto the front surface of the workpiece is controlled to be greater than the gas flow rate sprayed onto the back surface of the workpiece; the ratio of the gas flow rate sprayed onto the back surface of the workpiece to the gas flow rate on the front surface of the workpiece is (0.1 - 0.8):1; the gas flow rate sprayed onto the front surface of the workpiece is 20 - 35 sccm; the gas flow rate sprayed onto the back surface of the workpiece is 5 - 15 sccm.

2. The method according to claim 1, wherein The evacuation makes the vacuum degree of the deposition chamber be 10 -10 -10 -5 torr.

3. The method according to claim 1, wherein The preheating operation is to preheat the workpiece by using an air flow.

4. The method according to claim 1, wherein The preheating operation is to preheat the workpiece to 200 - 300 °C.

5. The method according to claim 1, wherein In the pre-deposition operation, the gas flow rate for providing the ionization ions to form the bombardment source is 10 - 30 sccm.

6. The method according to claim 1, wherein The operating power of the pre-deposition operation is 500 - 1500 W.

7. The method according to claim 1, wherein The time of the pre-deposition operation is 1 - 10 s.

8. The method according to claim 1, wherein The operating power of the deposition operation is 10 - 15 kW.

9. A physical vapor deposition apparatus using the method according to any one of claims 1-8, characterized in that, The physical vapor deposition device includes: At least two deposition chambers distributed in a ring shape; the deposition chambers are communicated with the transfer chamber; Each of the deposition chambers is provided with a fixed seat for fixing the target; And a carrying base opposite to the target; Each of the deposition chambers is respectively connected with a first gas supply device, a second gas supply device, and an air extraction device, and the target is electrically connected to the DC magnetron device.

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