Wafer coating device for optimizing ratio of step thickness to plane thickness of film layer

Abstract

The invention discloses a wafer coating device for optimizing the ratio of the thickness of a film layer step to the thickness of a plane, the wafer coating device comprises a working cavity, a carrying table, a target material and a collimator, in the coating process, metal atoms sputtered by the target material can penetrate through the collimator and fall onto a wafer borne by the carrying table, the collimator can block part of the metal atoms, and the metal atoms can pass through the working cavity. The atomic weight of metal deposited on the plane is reduced; the collimator comprises an upper mounting plate, a lower mounting plate and a metal corrugated pipe, the pipe wall of the metal corrugated pipe is corrugated, metal atoms can be efficiently captured and fixed, certain pressure can be borne, and adaptive elastic deformation is carried out; the distance between the upper mounting plate and the lower mounting plate is adjustable, so that the throughput of inclined atoms can be controlled according to process requirements, the plane thickness of a film layer on the surface of the wafer is reduced, the ratio of the step thickness of the film layer to the plane thickness is improved, and the film coating effect of the wafer is optimized.

Description

Technical Field

[0001] The present application relates to the field of wafer coating technology, and in particular to a wafer coating device for optimizing the ratio of film layer step thickness to plane thickness. Background Art

[0002] Magnetron sputtering is a type of physical vapor deposition (PVD), generally used to prepare metals, semiconductors, insulators and other materials. It has the advantages of simple equipment, easy control, large coating area and strong adhesion. Magnetron sputtering is a collision process between incident particles and targets. The incident particles undergo complex scattering in the target, collide with target atoms, and transfer part of the momentum to the target atoms. These target atoms collide with other target atoms, forming a cascade process. In this cascade process, some target atoms near the surface gain enough momentum to move outward, thus leaving the target and being sputtered out. The sputtered target atoms fall on the wafer, thus achieving the coating of the wafer.

[0003] In the magnetron sputtering process, when coating wafers with micropores, a collimator is generally installed between the target and the wafer to increase the micropore filling rate. The sputtered metal atoms or metal ions with large angles will hit the collimator, while the vertical and small-angle metal atoms or metal ions can be sputtered onto the wafer surface, thereby improving the overall step coverage.

[0004] However, existing collimators are usually fixed in form. During the debugging phase, it is necessary to repeatedly test different positions to find the optimal installation solution, which is time-consuming and labor-intensive, affecting work efficiency and increasing work costs. Summary of the invention

[0005] The purpose of the present application is to overcome the deficiencies in the prior art and to provide a wafer coating device that optimizes the ratio of the step thickness and the plane thickness of the film layer.

[0006] The present application provides a wafer coating device for optimizing the ratio of the step thickness and the plane thickness of the film layer, comprising: a working chamber for providing space for wafer coating; a carrier, arranged in the working chamber and used to receive the wafer; a target material, arranged in the working chamber and suspended above the carrier; a collimator, arranged in the working chamber and located between the target material and the carrier; during the coating process, metal atoms sputtered from the target material can pass through the collimator and fall onto the wafer received by the carrier; the collimator comprises: an upper mounting plate and a lower mounting plate, each of which is provided with a plurality of through holes, the through holes on the upper mounting plate corresponding one to one with the through holes on the lower mounting plate (120); a plurality of groups of metal bellows, arranged between the upper mounting plate and the lower mounting plate; any metal bellows is extended in the vertical direction and connected to a pair of corresponding perforations on the upper mounting plate and the lower mounting plate; during the coating process, metal atoms enter the metal bellows, and some of the metal atoms that move in an inclined manner are blocked by the metal bellows, so that the amount of metal atoms deposited on the plane is reduced; wherein the spacing between the upper mounting plate and the lower mounting plate is adjustable, and the metal bellows can adapt to the change in the spacing between the upper mounting plate and the lower mounting plate through elastic deformation; by adjusting the spacing between the upper mounting plate and the lower mounting plate, the shielding range of the collimator for the metal atoms can be changed, thereby increasing or reducing the amount of metal atoms allowed to pass through the collimator.

[0007] Further, the metal bellows is detachably arranged between the upper mounting plate and the lower mounting plate; and / or, the surface of the metal bellows is sandblasted to facilitate the adhesion of metal atoms.

[0008] Furthermore, at least one of the upper mounting plate and the lower mounting plate is provided with an electromagnet, which can attract the upper mounting plate and the lower mounting plate to be close to each other; changing the current intensity or changing the number of electromagnets can change the size of the attraction exerted on the upper mounting plate or the lower mounting plate, thereby changing the distance between the upper mounting plate and the lower mounting plate.

[0009] Furthermore, the wafer coating device for optimizing the ratio of the step thickness and the plane thickness of the film layer also includes a first mounting seat, which is used to place the electromagnet; a beam groove is also provided in the first mounting seat, and the cables of the electromagnet can be gathered in the beam groove; the first mounting seat is detachably connected to the collimator, and / or the electromagnet is detachably connected to the first mounting seat.

[0010] Furthermore, the wafer coating device for optimizing the ratio of the step thickness and the plane thickness of the film layer also includes a magnet, which is arranged around the metal bellows; the magnetic field formed by the magnet can confine electrons, thereby preventing the electrons from touching the wall and being lost.

[0011] Furthermore, the wafer coating device for optimizing the ratio of the step thickness and the plane thickness of the film layer also includes a second mounting seat, which is used to place the magnet; the second mounting seat is detachably connected to the collimator, and / or the magnet is detachably connected to the second mounting seat.

[0012] Furthermore, one of the upper mounting plate and the lower mounting plate is provided with a plurality of groups of electromagnets, which are distributed in a circumferential direction and surround the metal bellows; the other of the upper mounting plate and the lower mounting plate is provided with a plurality of groups of magnets, which are also distributed in a circumferential direction and surround the metal bellows; the magnets and the electromagnets are arranged opposite to each other; and the electromagnets can attract the magnets when energized.

[0013] Furthermore, the position of the collimator in the vertical direction is adjustable; by adjusting the position of the collimator in the vertical direction so that the collimator is close to or away from the target, the shielding range of the collimator for metal atoms can be changed, thereby increasing or decreasing the amount of metal atoms allowed to pass through the collimator.

[0014] Furthermore, the wafer coating device for optimizing the ratio of the step thickness and the plane thickness of the film layer also includes a lifting drive component, which is used to drive the collimator to move in the vertical direction; the lifting drive component includes: a rack, which is arranged on the collimator and extends in the vertical direction; a rotating drive member, the fixed end of which is arranged on the outer wall of the working chamber (1), and the movable end extends into the working chamber and is connected to the first gear; the second gear is rotatably arranged on the inner wall of the working chamber and is meshed with the rack and the first gear at the same time; when the height of the collimator needs to be adjusted, the rotating drive member is started to rotate the first gear, the first gear drives the second gear to rotate, and the second gear drives the rack and the collimator to move in the vertical direction.

[0015] Furthermore, the wafer coating device for optimizing the ratio of the step thickness and the plane thickness of the film layer also includes a shield, which is arranged between the collimator and the carrier; the shield is arranged in a cylindrical shape, which allows the carrier to be exposed under the collimator, and can shield the inner wall of the working chamber to prevent the inner wall of the working chamber from being contaminated.

[0016] The present application provides a wafer coating device for optimizing the ratio of the step thickness and the plane thickness of a film layer, comprising a working chamber, a carrier, a target material and a collimator. During the coating process, metal atoms sputtered from the target material can pass through the collimator and fall onto the wafer supported by the carrier. The collimator can block part of the metal atoms, thereby reducing the amount of metal atoms deposited on the plane. The collimator comprises an upper mounting plate, a lower mounting plate and a metal bellows. The wall of the metal bellows is corrugated, which can efficiently capture and fix metal atoms, withstand a certain pressure, and undergo adaptive elastic deformation. The spacing between the upper mounting plate and the lower mounting plate is adjustable, so as to control the amount of tilted atoms passing through according to process requirements, thereby reducing the plane thickness of the film layer on the surface of the wafer, improving the ratio of the step thickness and the plane thickness of the film layer, and optimizing the coating effect of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a wafer coating device for optimizing the ratio of the step thickness and the plane thickness of the film layer provided in the present application; Figure 2 for Figure 1 A schematic structural diagram of a collimator in a wafer coating device for optimizing the ratio of the step thickness to the plane thickness of the film layer is shown; Figure 3 A schematic diagram of the use of a collimator provided in this application; Figure 4 for Figure 3 A schematic diagram of the use of the collimator after the height is reduced; Figure 5 for Figure 3 A schematic diagram of the use of the collimator after the height is increased; Figure 6 A schematic diagram of another use of a collimator provided in this application. DETAILED DESCRIPTION

[0018] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0019] The present application provides a wafer coating device for optimizing the ratio of the step thickness and the plane thickness of the film layer, comprising: a working chamber 1, for providing a space for wafer coating; a carrier, arranged in the working chamber 1, for receiving the wafer; a target material 2, arranged in the working chamber 1 and suspended above the carrier; a collimator, arranged in the working chamber 1 and located between the target material 2 and the carrier; during the coating process, metal atoms sputtered from the target material 2 can pass through the collimator and fall onto the wafer received by the carrier.

[0020] Specifically, the working chamber 1 is provided with a wafer inlet and outlet, and a wafer handling mechanism such as a robot can transfer wafers into the working chamber 1 through the wafer inlet and outlet. The target material 2 is arranged at the top of the working chamber 1, and the carrier is arranged directly below the target material 2. The carrier can cooperate with the wafer handling mechanism to receive the wafer to be coated and make the wafer face the target material 2.

[0021] Furthermore, the working chamber 1 is also provided with an air inlet channel and an air outlet channel. The air inlet channel connects the working chamber 1 and the gas supply equipment, and the air outlet channel connects the working chamber 1 and the gas exhaust equipment. The gas supply equipment can pass the reaction gas for coating into the working chamber 1 through the air inlet channel, and the gas exhaust equipment can extract the gas in the working chamber 1 through the air outlet channel; the gas supply equipment and the gas exhaust equipment cooperate to maintain the intra-cavity air pressure required for the coating work.

[0022] Furthermore, the target material 2 is connected to a radio frequency power supply. When the target material 2 is working, the radio frequency power supply supplies power to the target material 2, and the target material 2 can ionize the reaction gas after being energized. After the reaction gas is ionized, the plasma bombards the target material 2, and the metal atoms on the surface of the target material 2 can be blasted out. The metal atoms move toward the carrier and are finally deposited on the surface of the wafer to achieve film coating on the wafer.

[0023] Since the bombardment angle of the plasma is irregular and non-directional, when the plasma bombards the target 2, the metal atoms ejected from the surface of the target 2 will also move irregularly and non-directionally under the action of the force. In this case, some metal atoms will fall vertically, while others will move downward at various angles and inclinations.

[0024] When coating a wafer with micropores, metal atoms that fall vertically and at a falling angle close to 90° are more likely to deposit in the micropores, while metal atoms that fall obliquely are more likely to deposit on a flat surface.

[0025] A collimator is arranged between the target 2 and the stage, and the collimator can block a part of the tilted metal atoms. Thus, under the same coating conditions, the collimator can reduce the metal atoms falling on the plane, thereby reducing the plane thickness of the film layer and increasing the ratio of the step thickness to the plane thickness of the film layer.

[0026] Furthermore, the collimator includes: an upper mounting plate 110 and a lower mounting plate 120, each of which is provided with a plurality of through holes 111, and the through holes 111 on the upper mounting plate 110 correspond one to one with the through holes 111 on the lower mounting plate 120; a plurality of groups of metal bellows 130 are arranged between the upper mounting plate 110 and the lower mounting plate 120; any metal bellows 130 is extended in a vertical direction and is connected to a corresponding pair of through holes 111 on the upper mounting plate 110 and the lower mounting plate 120; during the coating process, metal atoms enter the metal bellows 130, and some of the metal atoms that are tilted are blocked by the metal bellows 130, so that the amount of metal atoms deposited on the plane is reduced.

[0027] For details, please refer to Figure 1 and Figure 2 In the illustrated embodiment, the upper mounting plate 110 and the lower mounting plate 120 are both arranged in a circular plate shape, and the two are arranged side by side in the vertical direction, and a plurality of through holes 111 are arranged in an array on the plate surfaces of the two. The metal bellows 130 is arranged between the upper mounting plate 110 and the lower mounting plate 120. The upper end of any metal bellows 130 is connected to a through hole 111 on the upper mounting plate 110, and the lower end is connected to a through hole 111 on the lower mounting plate 120; the pipe of the metal bellows 130 and the through hole 111 form a vertically extending channel.

[0028] The metal bellows 130 is made of a thin-walled metal tube, and the tube wall is made corrugated through a specific processing technology. The corrugated structure makes the metal bellows 130 have good elasticity and flexibility, can withstand a certain pressure, and can perform adaptive elastic deformation.

[0029] Continue to refer to Figure 2 The metal bellows 130 and the perforations 111 form a vertical pipe that facilitates the movement of particles. Since the pipe wall of the metal bellows 130 is configured as a corrugated reciprocating folding structure, the inner wall of the vertical pipe has multiple layers of folds. During the coating process, after the metal atoms enter the vertical pipe, the metal atoms moving at a large angle will hit the pipe wall and be contained by the folds. The folded structure can effectively fix these metal atoms and prevent them from falling off after touching the wall, which ultimately affects the coating. In addition, the corrugated reciprocating folding structure of the metal bellows 130 can also increase the inner wall area of ​​the pipe to accommodate more metal atoms and increase the single use time of the collimator.

[0030] Furthermore, the distance between the upper mounting plate 110 and the lower mounting plate 120 is adjustable, and the metal bellows 130 can adapt to the change in the distance between the upper mounting plate 110 and the lower mounting plate 120 through elastic deformation; by adjusting the distance between the upper mounting plate 110 and the lower mounting plate 120, the shielding range of the collimator for metal atoms can be changed, thereby increasing or decreasing the amount of metal atoms allowed to pass through the collimator.

[0031] In one embodiment, at least one of the upper mounting plate 110 and the lower mounting plate 120 is connected to a driver (such as a pneumatic cylinder, an electric cylinder, etc.) and can move in a vertical direction under the drive of the driver, thereby changing the spacing between the upper mounting plate 110 and the lower mounting plate 120.

[0032] In another embodiment, at least one of the upper mounting plate 110 and the lower mounting plate 120 is threadedly connected to a screw rod. By rotating the screw rod, the upper mounting plate 110 or the lower mounting plate 120 can move linearly along the screw rod; by making the screw rod extend vertically, the distance between the upper mounting plate 110 and the lower mounting plate 120 can be changed by rotating the screw rod forward and backward.

[0033] In other embodiments, an adjustment structure such as a micrometer or a top screw may be used to adjust the relative position of the upper mounting plate 110 and the lower mounting plate 120, thereby changing the height of the collimator.

[0034] Since the metal bellows 130 is an elastic structure, when the upper mounting plate 110 and the lower mounting plate 120 are close to each other, the metal bellows 130 can adapt to the change of the collimator height through compression deformation; when the upper mounting plate 110 and the lower mounting plate 120 are away from each other, the metal bellows 130 can adapt to the change of the collimator height through tension deformation.

[0035] For details, please refer to Figure 3 In the illustrated embodiment, when the target 2 sputters metal atoms at a single point toward the vertical pipe directly below, metal atoms with a movement angle less than α will be blocked by the pipe wall, and only metal atoms with a movement angle between α and 90° can pass through the collimator and fall onto the wafer.

[0036] Combined with reference Figure 4 In the illustrated embodiment, the distance between the upper mounting plate 110 and the lower mounting plate 120 is reduced, and the metal bellows 130 is compressed; at this time, when the target 2 sputters metal atoms at a single point toward the vertical pipe directly below, metal atoms with a movement angle less than β will be blocked by the pipe wall, and only metal atoms with a movement angle between β and 90° can pass through the collimator and fall onto the wafer. α>β, at this time, the amount of metal atoms blocked by the collimator is reduced.

[0037] Combined with reference Figure 5 In the illustrated embodiment, the distance between the upper mounting plate 110 and the lower mounting plate 120 is increased, and the metal bellows 130 is stretched; at this time, when the target material 2 sputters metal atoms at a single point toward the vertical pipe directly below, metal atoms with a movement angle less than γ will be blocked by the pipe wall, and only metal atoms with a movement angle between γ and 90° can pass through the collimator and fall onto the wafer. α<γ, at this time, the amount of metal atoms blocked by the collimator increases.

[0038] From the above, we can see that when coating a wafer with micropores, metal atoms with a falling angle close to 90° are more likely to deposit in the micropores, while metal atoms falling at an angle are more likely to deposit on the plane. When confirming the wafer coating effect, the ratio of the step thickness and the plane thickness of the film layer is an important reference condition.

[0039] For example, the process requires that after coating, the ratio of the step thickness to the plane thickness of the film layer is 1:2~2.5. Under the same coating conditions, when the collimator is not used, most of the metal atoms are deposited on the flat surface of the wafer, resulting in a ratio of the step thickness to the plane thickness of the film layer of 1:4. After adding the collimator, some metal atoms that fall at an angle and will be deposited on the plane are blocked, while the amount of metal atoms that fall into the micropores remains unchanged, resulting in a change in the ratio of the step thickness to the plane thickness of the film layer to 1:3. At this time, it is necessary to increase the spacing between the upper mounting plate 110 and the lower mounting plate 120 so that the collimator can block more tilted atoms, and finally achieve a ratio of the step thickness to the plane thickness of the film layer of 1:2. Similarly, if adding a collimator results in a ratio of the surface film thickness to the hole filling thickness of 1:1.5, it is necessary to reduce the distance between the upper mounting plate 110 and the lower mounting plate 120 so that the amount of metal atoms blocked by the collimator is reduced and more tilted atoms fall onto the plane, thereby improving the ratio of the step thickness to the plane thickness of the film layer.

[0040] In summary, the wafer coating device provided by the present application can control the amount of metal atoms falling at an angle by adding a collimator, thereby reducing the planar thickness of the film layer on the surface of the wafer and improving the ratio of the step thickness and planar thickness of the film layer; by using the metal bellows 130 as the vertical pipe of the collimator, it can not only enhance the capture and fixation capabilities of the tilted atoms, but also quickly adapt and simplify the height adjustment operation of the collimator when the height of the collimator changes; the height of the collimator is made adjustable, and the amount of tilted atoms passing through can be effectively controlled according to the process requirements, thereby optimizing the wafer coating effect.

[0041] Optionally, the metal bellows 130 is detachably disposed between the upper mounting plate 110 and the lower mounting plate 120 .

[0042] For example, slots are provided on the upper mounting plate 110 and the lower mounting plate 120, and skirts are provided at both ends of the metal bellows 130; the metal bellows 130 can be installed by inserting the skirts into the slots; the metal bellows 130 can be disassembled by withdrawing the skirts from the slots.

[0043] For another example, magnets are provided on the upper mounting plate 110 and the lower mounting plate 120 , and the magnets can absorb the metal bellows 130 , thereby achieving the installation of the metal bellows 130 ; and the metal bellows 130 can be disassembled by overcoming the magnetic force of the magnets.

[0044] For another example, the metal bellows 130 is connected to the upper mounting plate 110 and the lower mounting plate 120 by screwing.

[0045] The present application does not limit the specific installation form of the metal bellows 130 .

[0046] The metal bellows 130 is detachable relative to the upper mounting plate 110 and the lower mounting plate 120. After being used for a period of time, the metal bellows 130 can be removed for cleaning, replacement, etc., to avoid too many metal atoms adhering to the tube wall of the metal bellows 130 after long-term use and losing the ability to capture newly generated metal atoms.

[0047] Optionally, the surface of the metal bellows 130 is sandblasted to facilitate adhesion of metal atoms.

[0048] At least the inner wall of the metal bellows 130 is processed by sandblasting. After sandblasting, the roughness of the wall of the metal bellows 130 increases, so that the metal bellows 130 can adhere to the metal atoms more firmly. The rough wall also provides more attachment points and a larger contact area for the metal atoms, which can effectively enhance the adhesion between the metal atoms and the surface of the bellows. In this way, it is possible to prevent the captured metal atoms from falling off and affecting the coating environment and the final wafer coating effect.

[0049] The sandblasting process enhances the stability and reliability of the metal bellows 130 during use.

[0050] In one embodiment, at least one of the upper mounting plate 110 and the lower mounting plate 120 is provided with an electromagnet 3, which can attract the upper mounting plate 110 and the lower mounting plate 120 to be close to each other; changing the current intensity or changing the number of electromagnets 3 can change the size of the attraction force on the upper mounting plate 110 or the lower mounting plate 120, thereby changing the distance between the upper mounting plate 110 and the lower mounting plate 120.

[0051] For details, please refer to Figure 2 In the illustrated embodiment, a plurality of electromagnets 3 are disposed on the top surface of the lower mounting plate 120 facing the upper mounting plate 110, and the plurality of electromagnets 3 are spaced apart in the circumferential direction and surround the metal bellows 130. The upper mounting plate 110 is made of ferromagnetic metal material. The metal bellows 130 is made of aluminum. When the spacing between the upper mounting plate 110 and the lower mounting plate 120 needs to be adjusted, the electromagnet 3 is energized to attract the upper mounting plate 110, so that the upper mounting plate 110 moves toward the lower mounting plate 120, thereby reducing the spacing between the upper mounting plate 110 and the lower mounting plate 120; at this time, the metal bellows 130 is compressed, and the elasticity of the metal bellows 130 counteracts the magnetic attraction, and finally the upper mounting plate 110 is stabilized.

[0052] When necessary, increasing the current of the electromagnet 3 can enhance the magnetism of the electromagnet 3, thereby further reducing the distance between the upper mounting plate 110 and the lower mounting plate 120. Similarly, reducing the current of the electromagnet 3 can weaken the magnetism of the electromagnet 3, thereby increasing the distance between the upper mounting plate 110 and the lower mounting plate 120.

[0053] Alternatively, a certain number of electromagnets 3 are selected to be energized as needed; when the number of energized electromagnets 3 increases, the attraction force on the upper mounting plate 110 increases, and the distance between the upper mounting plate 110 and the lower mounting plate 120 decreases; when the number of energized electromagnets 3 decreases, the attraction force on the upper mounting plate 110 decreases, and the distance between the upper mounting plate 110 and the lower mounting plate 120 increases.

[0054] The use of the electromagnet 3 makes it easier to adjust the height of the collimator.

[0055] In other embodiments, the electromagnet 3 can be arranged on the upper mounting plate 110, and the electromagnet 3 can be used to attract the lower mounting plate 120 to move; or, the electromagnet 3 can be set on the upper mounting plate 110 and the lower mounting plate 120 respectively, and the electromagnet 3 can be used to attract each other to make the upper mounting plate 110 and the lower mounting plate 120 move relative to each other.

[0056] The present application does not limit the specific configuration and installation method of the electromagnet 3 .

[0057] Optionally, a guide member is provided between the upper mounting plate 110 and the lower mounting plate 120 , and the guide member extends in the vertical direction to limit the movement direction of the upper mounting plate 110 and the lower mounting plate 120 when they approach or move away from each other.

[0058] The guide member may be any structure capable of guiding movement, such as a guide rod, a slide rail, etc. At least one of the upper mounting plate 110 and the lower mounting plate 120 is slidably disposed on the guide member and is limited in movement by the guide member.

[0059] When adjusting the distance between the upper mounting plate 110 and the lower mounting plate 120 , the upper mounting plate 110 and the lower mounting plate 120 can only move in the vertical direction under the limitation of the guide member, thereby ensuring the smooth flow of the vertical pipeline.

[0060] Optionally, the wafer coating device for optimizing the ratio of film step thickness and plane thickness provided in the present application also includes a first mounting seat 210, which is used to place the electromagnet 3; a wire harness groove is also provided in the first mounting seat 210, and the cables of the electromagnet 3 can be gathered in the wire harness groove.

[0061] The first mounting base 210 is provided to facilitate fixing the electromagnet 3 on the collimator.

[0062] Figure 1 and Figure 2 In the illustrated embodiment, the first mounting seat 210 is configured to be in the shape of an inverted groove with an open bottom surface, and the electromagnet 3 can be hidden in the inverted groove. The first mounting seat 210 can also protect the electromagnet 3; the first mounting seat 210 is in the shape of an annulus as a whole, and is disposed on the lower mounting plate 120 and surrounds the metal bellows 130.

[0063] When a plurality of electromagnets 3 are arranged through the first mounting seat 210, a plurality of slots may be provided in the first mounting seat 210, and any slot may be used to accommodate one electromagnet 3. The electromagnets 3 are limited by independent slots, which not only facilitates the installation of the electromagnets 3, but also prevents the electromagnets 3 from interfering with each other and from being displaced when the upper mounting plate 110 and the lower mounting plate 120 move relative to each other.

[0064] Furthermore, a cable trough is provided on one side of the first mounting seat 210. When multiple electromagnets 3 are arranged through the first mounting seat 210, multiple groups of cables can be gathered through the cable trough and finally led out from one outlet for external power supply. The cable trough can not only organize a large number of cables, but also facilitate the control of the lead-out line position, which is conducive to safe use.

[0065] In order to prevent the first mounting seat 210 from interfering with the external magnetism of the electromagnet 3 , the first mounting seat 210 may be made of a material with high magnetic permeability and low magnetic resistance (such as plastic, glass, etc.).

[0066] Optionally, the first mounting seat 210 is detachably connected to the collimator.

[0067] The first mounting seat 210 can be detachably disposed on the upper mounting plate 110 or the lower mounting plate 120 by means of screw connection, plug connection, buckle connection, etc. The present application does not limit the specific arrangement of the first mounting seat 210.

[0068] The first mounting seat 210 is detachable relative to the collimator. When the collimator needs to be cleaned, the first mounting seat 210 can be removed to facilitate the arrangement or replacement of parts. If the electromagnet 3 fails, the first mounting seat 210 can also be removed to repair the electromagnet 3.

[0069] Optionally, the electromagnet 3 is detachably connected to the first mounting seat 210 .

[0070] The electromagnet 3 can be detachably arranged in the first mounting seat 210 by means of snap-fitting, plug-in connection, tight fitting, etc.

[0071] The electromagnet 3 is detachable relative to the first mounting seat 210, which makes it more convenient to install, inspect and maintain the electromagnet 3. If necessary, it is also convenient to increase or decrease the number of electromagnets 3 in the first mounting seat 210 to adjust the magnetic field strength.

[0072] Optionally, the wafer coating device for optimizing the ratio of the step thickness and the plane thickness of the film layer provided in the present application also includes a magnet 4, which is arranged around the metal bellows 130; the magnetic field formed by the magnet 4 can confine electrons, thereby preventing the electrons from touching the wall and being lost.

[0073] The magnet 4 may be arranged in a circular ring shape, or a plurality of magnets 4 may be arranged distributed along the circumferential direction, so as to surround all the metal bellows 130 , thereby ensuring that the magnetic field fully acts on each metal bellows 130 .

[0074] It is easy to understand that during the coating process, the reaction gas is ionized to generate electrons, which need to bombard the target material 2 and continue to collide with gas particles to generate new electrons and ions. Therefore, it is necessary to reduce the loss of electrons in the working chamber 1.

[0075] In the wafer coating device provided in the present application, a large number of particles, including electrons, will enter the vertical pipe of the collimator. In order to prevent the loss of electrons due to wall contact during irregular movement, a circle of magnets 4 is arranged outside the metal bellows 130. The magnets 4 generate a magnetic field. When the electrons move in the magnetic field, they will be subject to the Lorentz force perpendicular to the direction of movement and the direction of the magnetic field. This force will change the trajectory of the electrons, thereby constraining the free movement of the electrons to a certain extent. The effect of the magnetic field on the electrons restricts the movement of the electrons. When the electrons approach the pipe wall, the magnetic field will change the direction of movement of the electrons, making it difficult for them to touch the wall and lose.

[0076] Optionally, the wafer coating device for optimizing the ratio of the step thickness and the plane thickness of the film layer provided in the present application further includes a second mounting seat 220 , and the second mounting seat 220 is used to place the magnet 4 .

[0077] The second mounting base 220 is provided to facilitate fixing the magnet 4 on the collimator.

[0078] Figure 1 and Figure 2 In the illustrated embodiment, the second mounting seat 220 is provided with a receiving groove with an open top surface, and the magnet 4 can be hidden in the receiving groove, and the second mounting seat 220 can also protect the magnet 4. The second mounting seat 220 is in an annular shape as a whole, and is provided on the bottom surface of the upper mounting plate 110 facing the lower mounting plate 120, and surrounds the metal bellows 130. At this time, the magnet 4 is close to the target material 2, which is conducive to maintaining the plasma environment below the target material 2 and promoting the sputtering of metal atoms.

[0079] When multiple magnets 4 are arranged through the second mounting seat 220, multiple slots can also be provided in the second mounting seat 220, and any slot can be used to accommodate one magnet 4. Using independent slots to limit the magnets 4 not only facilitates the installation of the magnets 4, but also avoids mutual interference between the magnets 4 and also avoids displacement of the magnets 4 when the upper mounting plate 110 and the lower mounting plate 120 move relative to each other.

[0080] In order to prevent the second mounting base 220 from interfering with the magnetic field, the second mounting base 220 may be made of a material with high magnetic permeability and low magnetic resistance (such as plastic, glass, etc.).

[0081] Optionally, the second mounting base 220 is detachably connected to the collimator.

[0082] The second mounting seat 220 can be detachably arranged on the upper mounting plate 110 or the lower mounting plate 120 by screwing, plugging, snapping, etc. The present application does not limit the specific arrangement of the second mounting seat 220.

[0083] The second mounting seat 220 is detachable relative to the collimator. When the collimator needs to be cleaned, the second mounting seat 220 can be removed to facilitate the arrangement or replacement of parts. If the magnet 4 fails, the second mounting seat 220 can also be removed to repair the magnet 4 therein.

[0084] Optionally, the magnet 4 is detachably connected to the second mounting seat 220 .

[0085] The magnet 4 can be detachably arranged in the second mounting seat 220 by means of snap-fitting, plug-in connection, tight fitting, etc.

[0086] The magnet 4 is detachable relative to the second mounting seat 220, which makes it more convenient to install, inspect and maintain the magnet 4. If necessary, it is also convenient to increase or decrease the number of magnets 4 in the second mounting seat 220 to adjust the magnetic field strength.

[0087] Optionally, one of the upper mounting plate 110 and the lower mounting plate 120 is provided with multiple groups of electromagnets 3, which are distributed in a circumferential direction and surround the metal bellows 130; the other of the upper mounting plate 110 and the lower mounting plate 120 is provided with multiple groups of magnets 4, which are also distributed in a circumferential direction and surround the metal bellows 130; the magnets 4 are arranged opposite to the electromagnets 3; and the electromagnets 3 can attract the magnets 4 when energized.

[0088] For details, please refer to Figure 2 In the illustrated embodiment, a circle of magnets 4 is provided on the bottom surface of the upper mounting plate 110 facing the lower mounting plate 120, and the magnets 4 are hidden in the second mounting seat 220; a circle of electromagnets 3 is provided on the top surface of the lower mounting plate 120 facing the upper mounting plate 110, and the electromagnets 3 are hidden in the first mounting seat 210. The magnets 4 can generate a magnetic field, constrain electrons, and prevent electrons from touching the wall and losing. When it is necessary to change the distance between the upper mounting plate 110 and the lower mounting plate 120, the electromagnets 3 are energized, and the electromagnets 3 can attract the magnets 4, so that the upper mounting plate 110 and the lower mounting plate 120 are close to each other to change the shielding range of the collimator for metal atoms, thereby increasing or reducing the amount of metal atoms allowed to pass through the collimator. During the debugging stage, the optimal distance between the upper mounting plate 110 and the lower mounting plate 120 can also be found by changing the input current of the electromagnets 3 or changing the number of energized electromagnets 3.

[0089] Optionally, the position of the collimator in the vertical direction is adjustable; by adjusting the position of the collimator in the vertical direction so that the collimator is close to or away from the target 2, the shielding range of the collimator for metal atoms can be changed, thereby increasing or decreasing the amount of metal atoms allowed to pass through the collimator.

[0090] For details, please refer to Figure 6 In the illustrated embodiments (1) and (2), the heights of the vertical pipes of the collimators are the same.

[0091] In embodiment (1), the distance between the collimator and the target 2 is a; in embodiment (2), the distance between the collimator and the target 2 is b; a<b.

[0092] In embodiment (1), when the target 2 sputters metal atoms from a single point toward the vertical pipe directly below, metal atoms with a movement angle less than δ will be blocked by the pipe wall, and only metal atoms with a movement angle between δ and 90° can pass through the collimator and fall onto the wafer.

[0093] In embodiment (2), when the target 2 sputters metal atoms from a single point toward the vertical pipe directly below, metal atoms with a movement angle smaller than ε will be blocked by the pipe wall, and only metal atoms with a movement angle between ε and 90° can pass through the collimator and fall onto the wafer.

[0094] Among them, δ<ε. Therefore, the farther the collimator is from the target 2, or in other words, the lower the collimator is in the vertical direction, the more metal atoms are blocked. When the ratio of the step thickness to the plane thickness of the film layer is too small, the collimator can be lowered to move the collimator away from the target 2 to block more tilted atoms, thereby reducing the metal atoms that can be deposited on the wafer surface; when the ratio of the surface coverage to the step coverage is too large, the collimator can be raised to move the collimator closer to the target 2 to allow more tilted atoms to pass through the collimator, thereby increasing the metal atoms that can be deposited on the wafer surface.

[0095] In one embodiment, a driver (such as a cylinder, an electric cylinder, etc.) is provided to be connected to the collimator, and the collimator can move in a vertical direction to approach or move away from the target material 2 under the drive of the driver.

[0096] In another embodiment, an adjustment structure such as a screw, a micrometer or a top screw is provided and connected to the collimator. A worker can operate the adjustment structure to move the collimator in the vertical direction so that the collimator is close to or away from the target 2 .

[0097] The present application does not limit the specific method of achieving the lifting and lowering of the collimator.

[0098] Figure 1 and Figure 2 In the embodiment shown, in the wafer coating device, the collimator can perform lifting and lowering movements, and the distance between the upper mounting plate 110 and the lower mounting plate 120 is adjustable. The double adjustment structure can increase the debugging range of the collimator and further improve the applicability of the collimator.

[0099] In a specific embodiment, the wafer coating device for optimizing the ratio of film step thickness and plane thickness provided in the present application also includes a lifting drive component, which is used to drive the collimator to move in the vertical direction; the lifting drive component includes: a rack 310, which is provided on the collimator and extends in the vertical direction; a rotating drive member 320, the fixed end of the rotating drive member 320 is provided on the outer wall of the working chamber 1, and the movable end extends into the working chamber 1 and is connected to the first gear 330; the second gear 340 is rotatably provided on the inner wall of the working chamber 1 and is meshed with the rack 310 and the first gear 330 at the same time; when the height of the collimator needs to be adjusted, the rotating drive member 320 is started to rotate the first gear 330, the first gear 330 drives the second gear 340 to rotate, and the second gear 340 drives the rack 310 and the collimator to move in the vertical direction.

[0100] For details, please refer to Figure 1 In the illustrated embodiment, the wafer coating device includes two sets of lifting drive components, which are symmetrically arranged along the left and right directions and can cooperate to support and adjust the height of the collimator. Among them, the rotary drive member 320 adopts a motor, the cylinder of the motor is fixedly arranged on the outer wall of the working chamber 1, and the rotating shaft is connected through a bellows sealed transmission connection, extending into the working chamber 1 and connected to the first gear 330; the first gear 330 is a bevel gear. On one side of the first gear 330, a second gear 340 is rotatably arranged on the inner wall of the working chamber 1 through a rotating mounting seat, and the second gear 340 is meshed with the first gear 330. A rack 310 is provided on the side of the collimator, and the rack 310 is extended in the vertical direction and meshed with the other side of the second gear 340. When working, the two sets of lifting drive components are started synchronously, the motor drives the first gear 330 to rotate, and drives the second gear 340 to rotate, and through the gear and rack cooperation, the second gear 340 pulls the rack 310 to move vertically. The coordination of the gears and racks on both sides can also limit the movement direction of the collimator, thereby improving the accuracy and stability of the collimator's lifting and lowering.

[0101] Optionally, the wafer coating device for optimizing the ratio of film step thickness and plane thickness provided in the present application also includes a shield 5, which is arranged between the collimator and the carrier. The shield 5 is arranged in a cylindrical shape, which allows the carrier to be exposed under the collimator and can shield the inner wall of the working chamber 1 to prevent the inner wall of the working chamber 1 from being contaminated.

[0102] For details, please refer to Figure 1 and Figure 2 In the illustrated embodiment, a circle of shielding plates 5 are provided on the bottom surface of the lower mounting plate 120 facing away from the upper mounting plate 110. The shielding plates 5 have a certain height, and the rack 310 is installed on the outer wall surface of the shielding plates 5. The table portion of the carrier for supporting the wafer is arranged in a truncated cone shape. During film coating, the shielding plates 5 are close to the table portion of the carrier, and the shielding plates 5 can surround the top of the table portion. The shielding plates 5 will not hinder the deposition of metal atoms on the wafer, and can separate the inner wall of the working chamber 1 to prevent metal atoms and pollutants generated by the coating from splashing onto the inner wall of the working chamber 1. After working for a period of time, the shielding plates 5 can also be cleaned to ensure a clean environment in the chamber.

[0103] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A wafer coating device for optimizing the ratio of the step thickness to the plane thickness of a film layer, characterized in that: include: A working chamber (1), used to provide space for wafer coating; A carrier, disposed in the working chamber (1) and used for receiving a wafer; A target material (2) is arranged in the working chamber (1) and suspended above the carrier; A collimator, disposed in the working chamber (1) and located between the target material (2) and the carrier; During the coating process, the metal atoms sputtered by the target material (2) can pass through the collimator and fall onto the wafer supported by the carrier; The collimator comprises: An upper mounting plate (110) and a lower mounting plate (120), wherein the upper mounting plate (110) and the lower mounting plate (120) are both provided with a plurality of through holes (111), and the through holes (111) on the upper mounting plate (110) correspond one-to-one to the through holes (111) on the lower mounting plate (120); A plurality of groups of metal bellows (130) are arranged between the upper mounting plate (110) and the lower mounting plate (120); Any of the metal bellows (130) is extended in the vertical direction and communicates with a corresponding pair of through holes (111) on the upper mounting plate (110) and the lower mounting plate (120); During the coating process, metal atoms enter the metal bellows (130), wherein a portion of the metal atoms that are tilted are blocked by the metal bellows (130), thereby reducing the amount of metal atoms deposited on the plane; The distance between the upper mounting plate (110) and the lower mounting plate (120) is adjustable, and the metal bellows (130) can adapt to the change in the distance between the upper mounting plate (110) and the lower mounting plate (120) through elastic deformation; By adjusting the distance between the upper mounting plate (110) and the lower mounting plate (120), the shielding range of the collimator on metal atoms can be changed, thereby increasing or reducing the amount of metal atoms allowed to pass through the collimator.

2. The wafer coating device for optimizing the ratio of the step thickness to the plane thickness of the film layer according to claim 1, characterized in that: The metal bellows (130) is detachably arranged between the upper mounting plate (110) and the lower mounting plate (120); And / or, the surface of the metal bellows (130) is sandblasted to facilitate adhesion of metal atoms.

3. The wafer coating device for optimizing the ratio of the step thickness to the plane thickness of the film layer according to claim 1, characterized in that: An electromagnet (3) is provided on at least one of the upper mounting plate (110) and the lower mounting plate (120), and the electromagnet (3) is capable of attracting the upper mounting plate (110) and the lower mounting plate (120) to move closer to each other; Changing the current intensity or the number of the electromagnets (3) can change the magnitude of the attractive force applied to the upper mounting plate (110) or the lower mounting plate (120), thereby changing the distance between the upper mounting plate (110) and the lower mounting plate (120).

4. The wafer coating device for optimizing the ratio of the step thickness to the plane thickness of the film layer according to claim 3, characterized in that: It also includes a first mounting seat (210), wherein the first mounting seat (210) is used to accommodate the electromagnet (3); A cable slit is also provided in the first mounting seat (210), and the cables of the electromagnet (3) can be bundled in the cable slit; The first mounting seat (210) is detachably connected to the collimator, and / or the electromagnet (3) is detachably connected to the first mounting seat (210).

5. The wafer coating device for optimizing the ratio of the step thickness to the plane thickness of the film layer according to claim 1, characterized in that: It also includes a magnet (4), wherein the magnet (4) is arranged around the metal bellows (130); The magnetic field formed by the magnet (4) can confine electrons, thereby preventing the electrons from hitting the wall and being lost.

6. The wafer coating device for optimizing the ratio of the step thickness to the plane thickness of the film layer according to claim 5, characterized in that: It also includes a second mounting seat (220), wherein the second mounting seat (220) is used to accommodate the magnet (4); The second mounting seat (220) is detachably connected to the collimator, and / or the magnet (4) is detachably connected to the second mounting seat (220).

7. The wafer coating device for optimizing the ratio of the step thickness to the plane thickness of the film layer according to claim 1, characterized in that: A plurality of groups of electromagnets (3) are provided on one of the upper mounting plate (110) and the lower mounting plate (120), and the plurality of groups of electromagnets (3) are distributed along a circumferential direction and surround the metal bellows (130); A plurality of groups of magnets (4) are provided on the other of the upper mounting plate (110) and the lower mounting plate (120), and the plurality of groups of magnets (4) are also distributed along the circumferential direction and surround the metal bellows (130); The magnet (4) and the electromagnet (3) are arranged opposite to each other; The electromagnet (3) is capable of attracting the magnet (4) when energized.

8. The wafer coating device for optimizing the ratio of the step thickness to the plane thickness of the film layer according to claim 1, characterized in that: The position of the collimator in the vertical direction is adjustable; By adjusting the position of the collimator in the vertical direction so that the collimator is close to or away from the target material (2), the shielding range of the collimator for metal atoms can be changed, thereby increasing or decreasing the amount of metal atoms allowed to pass through the collimator.

9. The wafer coating device for optimizing the ratio of the step thickness to the plane thickness of the film layer according to claim 8, characterized in that: It also includes a lifting drive assembly, which is used to drive the collimator to move in a vertical direction; The lifting drive assembly comprises: A rack (310) is provided on the collimator and extends in a vertical direction; a rotary drive member (320), wherein a fixed end of the rotary drive member (320) is arranged on the outer wall of the working chamber (1), and a movable end extends into the working chamber (1) and is connected to the first gear (330); a second gear (340) rotatably disposed on the inner wall of the working chamber (1) and meshing with the rack (310) and the first gear (330); When the height of the collimator needs to be adjusted, the rotary drive member (320) is started to rotate the first gear (330), the first gear (330) drives the second gear (340) to rotate, and the second gear (340) drives the rack (310) and the collimator to move in a vertical direction.

10. The wafer coating device for optimizing the ratio of the step thickness to the plane thickness of the film layer according to any one of claims 1 to 9, characterized in that: It also comprises a shielding plate (5), wherein the shielding plate (5) is arranged between the collimator and the carrier; The shielding plate (5) is arranged in a cylindrical shape, which allows the carrier to be exposed below the collimator, and can also shield the inner wall of the working chamber (1) to prevent the inner wall of the working chamber (1) from being contaminated.

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