CN117867454B

CN117867454B - Device for improving metal film reflow efficiency by PVD

Info

Publication number: CN117867454B
Application number: CN202410278561.1A
Authority: CN
Inventors: 许磊; 王世宽; 宋永辉
Original assignee: Wuxi Shangji Semiconductor Technology Co ltd
Current assignee: Wuxi Shangji Semiconductor Technology Co ltd
Priority date: 2024-03-12
Filing date: 2024-03-12
Publication date: 2024-06-04
Anticipated expiration: 2044-03-12
Also published as: CN117867454A

Abstract

The application provides a PVD device for improving metal film reflow efficiency, which comprises a sputtering cavity, a lifting carrier part, an auxiliary cavity and a cover piece; the sputtering cavity is used for coating the wafer; the lifting carrier part comprises a wafer heating carrier capable of lifting along the vertical direction, an electrostatic absorption part positioned at the top of the wafer heating carrier, and an air path penetrating through the wafer heating carrier and the electrostatic absorption part; the auxiliary cavity is positioned on one side surface of the sputtering cavity and communicated with the sputtering cavity; the cover piece runs between the sputtering cavity and the auxiliary cavity, and an exhaust hole is arranged in the center of the top of the cover piece; when the cover member is operated into the sputtering cavity, the cover member covers the wafer and forms an auxiliary heating chamber between the cover member and the electrostatic absorption member, hot air enters the auxiliary heating chamber from the air path, flows through the back surface of the wafer, the side surface of the wafer and the front surface of the wafer in sequence, and finally is discharged from the exhaust hole. The application realizes uniform heating and compression of the wafer surface, reduces the time of back flow hole filling of the metal film and improves the efficiency of wafer film coating.

Description

Device for improving metal film reflow efficiency by PVD

Technical Field

The invention relates to the technical field of PVD (physical vapor deposition), in particular to a device for improving metal film reflow efficiency by PVD.

Background

Physical Vapor Deposition (PVD) is a technique of vaporizing a material source (solid or liquid) surface into gaseous atoms or molecules or partially ionizing the material source into ions by a physical method under vacuum conditions and depositing a thin film having a specific function on a wafer surface through a low-pressure gas (or plasma) process, and physical vapor deposition is one of the main surface treatment techniques. With the improvement of deposition methods and techniques, physical vapor deposition techniques are widely used in the semiconductor industry.

In power MOS or IGBT product design, deep holes or trenches with diameters of 0.2 μm to 1 μm and depths of 0.2 μm to 2 μm are etched in Si-based or SiC-based wafers. Metallic Al as an electrode conductive material is required to completely fill the deep holes or trenches of such wafers.

To ensure the Filling effect, a Reflow forming process is often used. According to the process, the wafer sputtered with the metal film with a certain thickness is heated through the heating function of the wafer heating carrier (heater), so that the temperature of the wafer is close to the melting point of the metal Al, the metal Al in a molten state slowly flows (i.e. a Reflow process) into the deep hole or the groove to realize complete filling of the Al, but the Reflow hole filling time of the metal Al film is longer, and half an hour to one hour is needed for filling different hole patterns, so that the time required by film coating of the whole wafer is increased, and the film coating efficiency is low.

In the prior art, the wafer after film coating is transferred, and the metal film is accelerated to flow back by heating the wafer surface through a heating wire, but the wafer surface is heated unevenly, heat loss can be generated in the wafer transferring process, the speed of local metal film backflow is easy to influence, and the problem that the metal film is bridged and sealed in advance due to rapid deposition is also difficult to solve.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a device for improving the reflow efficiency of a metal film by PVD, which is used for uniformly heating and pressing the surface of a wafer, reducing the time for filling holes by reflow of the metal film and improving the film coating efficiency of the wafer. The technical scheme adopted by the invention is as follows:

an apparatus for PVD to improve reflow efficiency of a metal film, comprising:

the sputtering cavity is used for coating the wafer;

the lifting carrier part comprises a wafer heating carrier capable of lifting along the vertical direction, an electrostatic absorption part positioned at the top of the wafer heating carrier, and an air path penetrating through the wafer heating carrier and the electrostatic absorption part;

the auxiliary cavity is positioned on one side surface of the sputtering cavity and is communicated with the sputtering cavity;

the cover piece runs between the sputtering cavity and the auxiliary cavity, and an exhaust hole is formed in the center of the top of the cover piece;

a transfer member for transferring the cover member;

When the cover member is operated into the sputtering cavity, the cover member covers the wafer and forms an auxiliary heating chamber between the cover member and the electrostatic absorption member, hot air enters the auxiliary heating chamber from the air path, flows through the back surface of the wafer, the side surface of the wafer and the front surface of the wafer in sequence, and finally is discharged from the exhaust hole.

Further, a rocker arm is arranged on the transfer member, one end of the rocker arm is configured to be a hook part, and the outer wall of the cover member is mounted on the hook part.

Further, a cover heating element is arranged in the auxiliary cavity.

Further, a temperature monitoring piece is arranged between the cover piece heating piece and the cover piece.

Further, the surface of the electrostatic absorption member is provided with:

The air guide groove is communicated with the air channel;

The punctiform bulge is used for supporting the wafer.

Further, annular protrusions are arranged on the surface of the outer edge of the electrostatic absorption part; the cover member can cover the outer edge and cover the annular protrusion.

Further, the elevating stage section further includes:

Perforation, vertically penetrating through the wafer heating carrier and the electrostatic absorption part;

The ejector pin extends along the vertical direction, and the top of the ejector pin stretches into the perforation.

Further, a gasket is arranged at the top end of the perforation, and the ejector pin can eject the gasket out of the electrostatic absorption part.

The gasket bottom is provided with the gasket arch, the thimble top is provided with the thimble recess, when the thimble with the gasket contact the gasket protruding entering in the thimble recess.

Further, the perforated top is provided with a perforated step, and the gasket can be carried at the perforated step so that the gasket does not protrude from the plane of the electrostatic absorption member.

The invention has the advantages that:

A relatively narrow and high-pressure auxiliary heating chamber is formed between the cover piece and the wafer heating carrier, hot inert gas is temporarily stored in the auxiliary heating chamber for downwards pressing the deposited metal film on the surface of the wafer, the metal film is assisted to flow back into a hole or a groove on the surface of the wafer while the surface of the wafer is heated, heating and pressurizing are integrated, the backflow hole filling efficiency of the metal film is accelerated, and meanwhile, the auxiliary heating chamber can well maintain a high-temperature environment and avoid heat loss;

the hot inert gas enters the auxiliary heating chamber from the gas circuit, flows through the back surface of the wafer, the side surface of the wafer and the front surface of the wafer in sequence, and finally is discharged from the exhaust hole to the auxiliary heating chamber, so that the wafer is heated more uniformly;

The cover piece is transferred into the sputtering cavity after being preheated in the auxiliary cavity, the preheated cover piece has high temperature, on one hand, the front surface of the wafer is heated by heat radiation, on the other hand, the inert gas in the auxiliary thermal cavity is heated, the temperature difference and the heat loss are reduced, and the efficiency of back flow hole filling of the metal film is further improved;

The position of the wafer is unchanged in the whole reflow hole filling process, so that the problems of device performance deviation and uneven product quality parameters after processing caused by temperature difference and uneven wafer surface temperature in the wafer transferring process are avoided;

The transfer piece automatically transfers, the degree of automation is high, and the movement track of the rocker arm avoids the positions of other parts in the sputtering cavity, so that the cover piece is not influenced to cover the electrostatic absorption piece.

Drawings

Fig. 1 is a perspective view of the present invention.

Fig. 2 is a plan cross-sectional view of the present invention.

Fig. 3 is a top cross-sectional view of the present invention.

Fig. 4 is an assembly view of the cover and the lift table portion when the auxiliary thermal chamber of the present invention is formed.

Fig. 5 is a partial enlarged view of fig. 4 at a.

FIG. 6 is a diagram of an embodiment of a wafer heating stage.

Fig. 7 is a first view cross-section of the present invention.

Fig. 8 is a second view cross-section of the present invention.

Fig. 9 is a partial enlarged view at B in fig. 8.

In the figure: 100-sputtering chamber, 100a, inlet and outlet channel, 110-shielding piece, 200-elevating stage part, 210-wafer heating stage, 220-electrostatic absorption piece, 221-air guide groove, 222-point-shaped bulge, 223-outer edge, 224-annular bulge, 230-air channel, 240-perforation, 250-thimble, 251-needle groove, 260-gasket, 261-gasket bulge, 300-auxiliary cavity, 310-cover piece heating piece, 320-temperature monitoring piece, 400-cover piece, 410-exhaust hole, 500-auxiliary heating chamber, 600-transfer piece, 610-rocker arm and 611-hook part.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

Referring to fig. 1-5, the present invention provides a PVD apparatus for improving reflow efficiency of a metal film, comprising a sputtering chamber 100, a lifting platform part 200, a sub-chamber 300, a cover 400, and a transfer member 600; the sputtering chamber 100 is used for wafer film coating; the elevating platform part 200 comprises a wafer heating platform 210 capable of elevating along the vertical direction, an electrostatic absorption part 220 positioned at the top of the wafer heating platform 210, and an air path 230 penetrating through the wafer heating platform 210 and the electrostatic absorption part 220; the auxiliary chamber 300 is located at one side of the sputtering chamber 100 and is communicated with the sputtering chamber 100; the cover 400 is operated between the sputtering chamber 100 and the sub-chamber 300, and an exhaust hole 410 is provided at the center of the top of the cover 400; the transfer member 600 is used for transferring the cover member 400; when the cover 400 is moved into the sputtering chamber 100, the cover 400 covers the wafer and forms an auxiliary thermal chamber 500 between the cover 400 and the electrostatic absorption member 220, and the hot air enters the auxiliary thermal chamber 500 from the air path 230, flows through the back surface of the wafer, the side surface of the wafer, and the front surface of the wafer, and finally is discharged from the exhaust hole 410.

As an embodiment of the application, wafer heating stage 210 is heater and electrostatic chuck 220 is an ESC, all conventional PVD components.

Referring to fig. 5-6, at the beginning of the film coating operation, the wafer is placed into the sputtering chamber 100 through the access port 100a and is adsorbed and fixed on the electrostatic adsorption member 220, and the cover member 400 is located in the sub-chamber 300. The wafer heating stage 210 lifts the wafer up to the same level as the shutter 110 for the film coating operation. After the film coating operation is completed, the wafer heating carrier 210 is lowered to a designated position, and the cover 400 is transferred from the auxiliary chamber 300 into the sputtering chamber 100 and is matched with the electrostatic absorption member 220 to form an auxiliary heat chamber 500, and the heat loss can be reduced due to the closed space, small volume and concentrated heat of the auxiliary heat chamber 500; the hot air enters the auxiliary heating chamber 500 from the air path 230, flows through the back surface, the side surface and the front surface of the wafer, and finally is discharged from the exhaust hole 410 to the auxiliary heating chamber 500, so as to comprehensively heat the wafer.

In the embodiment, inert gas Ar is selected as the hot gas, so that the safety in the wafer processing process is improved.

The movement path of the inert gas can be known, the inert gas enters the auxiliary thermal chamber 500 from the center of the electrostatic absorption member 220, the wafer is lifted up from the surface of the electrostatic absorption member 220 for a certain distance, gaps exist between the wafer and the electrostatic absorption member 220, the inert gas uniformly and outwards diverges to the side surface of the wafer from the center of the auxiliary thermal chamber 500, then upwards moves along the side surface of the wafer, then gathers towards the center of the auxiliary thermal chamber 500, and finally overflows from the exhaust hole 410; the inert gas with larger flow rate can temporarily exist in the auxiliary thermal chamber 500, so that the auxiliary thermal chamber 500 forms a high-temperature and high-pressure environment relative to the sputtering chamber 100, downward pressure is formed on the surface of the deposited metal film when the inert gas passes over the wafer, the metal film is helped to flow back into holes or grooves on the surface of the wafer, and particularly the holes on the surface of the wafer are sealed by the metal film, the effect is better, because the metal film at the sealing position flows back into the holes faster under the pushing of the air pressure above, the problems of bridging sealing in advance and increasing the difficulty of backflow of the metal film caused by rapid deposition are solved;

In the whole process of metal film reflow hole filling, the contact between inert gas and the surface of the wafer is more uniform, the wafer is heated more uniformly, and compared with the mode of heating the wafer by a heating wire, the method has the advantage that the local temperature difference on the surface of the wafer is prevented from influencing the quality of products.

It should be noted that multiple wafer movements should be avoided as much as possible in PVD processes; because the temperature is a key influencing factor in the metal reflow process, when wafers are heated by transferring wafers in different chambers, the temperature difference in the different chambers is larger, so that the heating time of the parts of the wafers which are removed from the auxiliary chambers is longer, the temperature distribution on the surfaces of the wafers is uneven, and the problems of larger product performance deviation and uneven product quality after the wafers are processed are more easily caused. Therefore, in the whole process of metal film reflow hole filling, the wafer is always positioned in the auxiliary heating chamber 500 and is not transferred, the temperature change of the surface of the wafer is uniform no matter the wafer is in a heating environment or a deposition environment, and the condition of local temperature difference is avoided, so that the stability of the performance of a wafer processing product is further ensured.

In addition, in the present application, the path of the gas path 230 is not specific, and only hot gas needs to be led to the wafer surface; the axis of the vent hole 410 preferably coincides with the axis of the cover 400, i.e., the vent hole 410 is located at the center of the cover 400, and the hot gas diffused from the wafer circumference is uniformly diffused inward again, so that the wafer surface is uniformly heated.

In order to enhance the integrated operation of the lamination process, as shown in fig. 2-3, the transfer member 600 of the present application is disposed within the sputtering chamber 100; a rocker arm 610 is disposed on the transfer member 600, one end of the rocker arm 610 is configured as a hook 611, and the outer wall of the cover member 400 is mounted on the hook 611; the hook 611 is in a major arc shape or a ring shape, and the flange surface is configured outside the cover 400, so that the cover 400 can be mounted on the hook 611, the hook 611 is prevented from interfering with the positional relationship between the cover 400 and the electrostatic absorption member 220, and the heating effect of the cover is ensured.

As an embodiment of the present application, the transferring member 600 is a common rotation driving device such as a motor or a rotary cylinder, one end of the rocker arm 610 is connected to the output end of the motor, and the cover member 400 is transferred into the sputtering chamber 100 or the auxiliary chamber 300 by clockwise or counterclockwise rotation of the motor;

specifically, in the use process, after the film coating operation is completed, the wafer heating carrier 210 is lowered to a designated position, the transferring member 600 drives the rocker arm 610 to swing, and the heated cover 400 is transferred into the sputtering chamber 100 and directly above the electrostatic suction member 220, and the wafer heating carrier 210 is raised to cover the wafer by the cover 400.

As another embodiment of the present application, the transferring member 600 is a combination of a rotary driving device such as a motor and a linear driving device such as a linear cylinder, so as to implement swinging of the rocker arm 610 in a horizontal plane and lifting of the lid 400 in a vertical direction.

Specifically, in the use process, after the film coating operation is completed, the wafer heating carrier 210 descends to a designated position, the rotary driving device drives the swing arm 610 to swing, the heated cover 400 is transferred into the sputtering chamber 100 and directly above the electrostatic suction member 220, and then the linear driving device drives the swing arm 610 to descend so that the cover 400 covers the wafer.

As other embodiments of the present application, the transferring member 600 is a rotary power transmission device such as a gear set, a conveyor belt, a rotary cylinder, a sprocket chain, etc., and the swinging of the rocker arm 610 is realized by linking the transferring member to a power source inside or outside the sputtering chamber 100, so that the transferring in the sputtering chamber 100 and the auxiliary chamber 300 of the cover member 400 is realized.

In the present application, a cover heating member 310 is provided in the sub-chamber 300; the sputtering chamber 100 communicates with the sub-chamber 300, and the lid 400 is heated by the lid heater 310 while inside the sub-chamber 300, thereby achieving preheating of the lid 400.

When the cover 400 is not preheated, the inert gas flows upward to the front surface of the wafer, and the heat exchange between part of the inert gas and the cover 400 reduces the temperature of the part of the inert gas, so that a certain heat loss is caused, and the heating effect is affected. Therefore, the cover 400 is preheated to a temperature higher than that of the inert gas, so that after the cover 400 is covered on the electrostatic absorption member 220, the cover 400 not only avoids heat loss generated by the inert gas, but also heats the inert gas and the front surface of the wafer in the auxiliary heat chamber 500 through heat radiation, thereby improving the heat utilization rate, comprehensively accelerating the speed of reflow hole filling of the metal film, and improving the efficiency of film coating of the wafer.

In order to monitor the heating temperature of the cover 400, for convenience of temperature control, referring to fig. 7 to 8, a temperature monitor 320 is disposed between the cover heating member 310 and the cover 400.

Preferably, the cover heating member 310 and the temperature monitoring member 320 are respectively provided at the upper and lower sides of the cover 400, and the upper and lower sides of the cover 400 are respectively preheated and monitored for temperature;

In some embodiments, the cover heater 310 is a heat lamp; the temperature monitor 320 is an infrared temperature sensor, and the temperature monitor 320 is preferably located at the center of the cover heating member 310; the heating lamps are annularly arranged at the outer circumference of the infrared temperature sensor, and uniformly heat the cover 400 by heat radiation; first, the heating speed of the cover 400 is faster and more uniform by heating the upper and lower sides of the cover 400, the temperature of the cover 400 is monitored by the temperature monitoring member 320, and the transferring member 600 can transfer the cover 400 when the cover 400 is heated to a set temperature.

Further, as an embodiment of the present application, the cover heating member 310 is directly provided on the cover 400 to move in synchronization with the cover 400; this way of directly heating the cover 400 is more convenient, and the heating position of the cover 400 is not limited to the sub-chamber 300, so that the cover 400 can be preheated during the transferring process of the cover 400, thereby further saving the process time.

Further, the electrostatic absorption member 220 has an air guide groove 221 and a dot-shaped protrusion 222 on its surface; the air guide groove 221 is communicated with the air channel 230; the dot-shaped protrusions 222 are used to support the wafer.

Specifically, the air guide groove 221 includes a plurality of circular grooves that diffuse from inside to outside and a plurality of radially extending strip-shaped grooves, wherein the strip-shaped grooves communicate with the plurality of circular grooves; when the wafer is adsorbed on the electrostatic adsorption piece 220, the punctiform protrusions 222 are in contact with the back surface of the wafer, so that a certain gap exists between the sinking surface of the electrostatic adsorption piece 220 and the wafer, inert gas is convenient to overflow from the opening of the gas path 230, and therefore hot gas enters the gas guide groove 221 from the opening of the gas path 230 and is diffused to the edge of the wafer along the gas guide groove 221 from the back surface of the wafer; the process simulates the motion trail of the inert gas Ar in the metal Al reflow process, so that the inert gas is more uniformly diffused.

As other embodiments of the present application, the inert gas has at least two heating modes: the first method is to heat the lower surface of the wafer and the inert gas by using the heating function of the wafer heating carrier 210 itself with the electric heating wire, and the inert gas is used only as an indirect heat conduction medium; the second of which may be heated by a heating element or system external to the sputtering chamber 100 before the inert gas enters the gas path 230.

In addition, in order to facilitate the positioning of the cover 400 on the electrostatic absorption member 220, the cover 400 is prevented from touching the wafer, and the surface of the outer edge 223 of the electrostatic absorption member 220 is provided with an annular protrusion 224; the cover 400 can cover the outer rim 223 and enclose the annular projection 224.

In order to facilitate the removal and placement of the wafer on the electrostatic chuck 220, referring to fig. 7-9, the lift stage 200 further includes a through hole 240 and a thimble 250; the through holes 240 vertically penetrate through the wafer heating stage 210 and the electrostatic absorption member 220; the ejector pins 250 extend in a vertical direction with their tops extending into the perforations 240.

The number of the through holes 240 and the ejector pins 250 is plural, and the through holes and the ejector pins 250 are uniformly distributed in a ring shape based on the axis of the wafer heating carrier 210; the thimble 250 is fixed at the inner bottom of the sputtering cavity 100; the wafer heating stage 210 descends, the top of the ejector pins 250 are exposed from the top of the electrostatic suction member 220, the wafer is placed on the ejector pins 250, then the wafer heating stage 210 ascends, the ejector pins 250 are gradually hidden in the through holes 240, and the wafer is sucked and fixed by the electrostatic suction member 220.

In order to avoid the roughness of the surface of the ejector pins 250 and scratching the surface of the wafer when the ejector pins 250 contact the wafer, referring to fig. 7-9, the top ends of the through holes 240 are provided with pads 260, and the ejector pins 250 can eject the pads 260 out of the electrostatic absorption member 220.

As one embodiment of the present application, the ejector pins 250 are not connected to the spacer 260, and are specifically understood as: a gasket bulge 261 is arranged at the bottom of the gasket 260, and a thimble groove 251 is arranged at the top of the thimble 250; when the ejector pins 250 contact the pads 260, the pad protrusions 261 enter the ejector pin grooves 251.

The gasket protrusions 261 and the thimble grooves 251 are preferably distributed uniformly, and the gasket protrusions 261 and the thimble grooves 251 are matched with each other to prevent the gasket 260 from shaking and falling, so that the gasket 260 is used for preventing the surface of the wafer from being scratched, the contact area with the wafer is increased, and the placement stability of the wafer is improved;

in addition, the gasket 260 can also ensure that the perforation 240 is plugged during the reflow of the metal film, avoiding leakage of inert gas from the perforation 240.

As another embodiment of the present application, ejector pins 250 are secured to spacer 260.

Further, after the pad 260 is disposed, in order to avoid that the pad 260 affects the adsorption effect of the wafer, as shown in fig. 9, a perforated step is disposed at the top of the through hole 240 (i.e. the surface of the electrostatic adsorption element 220), and the pad 260 can be carried on the perforated step, so that the pad 260 does not protrude from the plane of the electrostatic adsorption element 220; when the wafer heating stage 210 is lifted, the pad 260 gradually falls into the through hole step until the wafer is adsorbed on the surface of the electrostatic adsorption component 220, the wafer heating stage 210 is lifted, and the pad 260 is completely separated from the wafer.

In conclusion, the device for improving the reflow efficiency of the metal film by PVD reduces the time of filling holes by reflow of the metal film, improves the efficiency of wafer coating, and is convenient for intelligent operation due to centralized components.

Finally, it should be noted that the above-mentioned embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications and equivalents may be made to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention, and all such modifications and equivalents are intended to be encompassed in the scope of the claims of the present invention.

Claims

1. An apparatus for improving reflow efficiency of a metal film by PVD, comprising:

a sputtering chamber (100) for wafer coating;

A lifting stage part (200) comprising a wafer heating stage (210) capable of lifting along the vertical direction, an electrostatic absorption part (220) positioned at the top of the wafer heating stage (210), and an air path (230) penetrating through the wafer heating stage (210) and the electrostatic absorption part (220);

the auxiliary cavity (300) is positioned on one side surface of the sputtering cavity (100) and is communicated with the sputtering cavity (100);

A cover (400) which runs between the sputtering chamber (100) and the auxiliary chamber (300), wherein an exhaust hole (410) is arranged at the center of the top of the cover (400);

A transfer member (600) for transferring the cover member (400);

when the cover member (400) is operated into the sputtering cavity (100), the cover member (400) covers the wafer, an auxiliary heat chamber (500) is formed between the cover member (400) and the electrostatic absorption member (220), hot air enters the auxiliary heat chamber (500) from the air path (230), flows through the back surface of the wafer, the side surface of the wafer and the front surface of the wafer in sequence, and finally is discharged from the exhaust hole (410) to the auxiliary heat chamber (500).

2. The device for improving reflow efficiency of a metal film by PVD according to claim 1, wherein: the transfer piece (600) is provided with a rocker arm (610), one end of the rocker arm (610) is configured into a hook portion (611), and the outer wall of the cover piece (400) is mounted on the hook portion (611).

3. The device for improving reflow efficiency of a metal film by PVD according to claim 1, wherein: a cover heating element (310) is arranged in the auxiliary cavity (300).

4. A device for improving reflow efficiency of a metal film by PVD according to claim 3, wherein: a temperature monitoring member (320) is arranged between the cover member heating member (310) and the cover member (400).

5. Device for PVD improvement of reflow efficiency of metal films according to any of claims 1-4, characterized in that the surface of the electrostatic suction member (220) is provided with:

An air guide groove (221) communicated with the air path (230);

and the dot-shaped bulges (222) are used for bearing the wafer.

6. The device for improving reflow efficiency of metal films by PVD according to claim 5, wherein: the surface of the outer edge (223) of the electrostatic absorption part (220) is provided with an annular bulge (224);

the cover (400) can cover the outer edge (223) and cover the annular protrusion (224).

7. The PVD apparatus for improving reflow efficiency of metal films according to claim 1, wherein the lift stage portion (200) further comprises:

a through hole (240) penetrating the wafer heating stage (210) and the electrostatic adsorbing member (220) vertically;

the thimble (250) extends along the vertical direction, and the top of the thimble extends into the perforation (240).

8. The device for improving reflow efficiency of a metal film by PVD according to claim 7, wherein: the top end of the through hole (240) is provided with a gasket (260), and the ejector pin (250) can eject the gasket (260) out of the electrostatic absorption part (220).

9. The device for improving reflow efficiency of a metal film by PVD according to claim 8, wherein: the bottom of the gasket (260) is provided with a gasket bulge (261), the top of the thimble (250) is provided with a thimble groove (251), and when the thimble (250) is contacted with the gasket (260), the gasket bulge (261) enters the thimble groove (251).

10. The device for improving reflow efficiency of a metal film by PVD according to claim 8, wherein: the top of the perforation (240) is provided with a perforation step, and the gasket (260) can be carried at the perforation step, so that the gasket (260) does not protrude out of the plane of the electrostatic absorption part (220).