CN113416938B - Sputtering equipment and method capable of adjusting film stress - Google Patents

Abstract

The invention provides sputtering equipment and a method capable of adjusting film stress. The equipment comprises a cavity, a magnetron sputtering device, a baffle, a wafer pressure ring, a base and an electromagnetic coil module; one end of the wafer pressure ring is adjacent to the baffle plate, and the other end of the wafer pressure ring extends to the upper part of the edge of the base; the base is connected with a bias power supply; the electromagnetic coil module is positioned in the base and/or between the wafer pressure ring and the base and comprises a plurality of electromagnetic coil groups, wherein each electromagnetic coil group comprises an N-pole electromagnet and an S-pole electromagnet, the N-pole electromagnets in the single electromagnetic coil group are adjacently arranged on the left side of the S-pole electromagnet, and the N-pole magnetic pole surface of the N-pole electromagnet and the S-pole magnetic pole surface of the S-pole electromagnet face upwards or downwards simultaneously; in the sputtering process, the plurality of electromagnetic coils are divided into a plurality of electrifying units, and the plurality of electrifying units are sequentially and alternately electrified in the clockwise direction or the anticlockwise direction so as to deposit a film on the surface of the substrate and adjust the stress of the film. The invention is helpful to improve the film thickness and the stress distribution uniformity.

Description

Sputtering equipment and method capable of adjusting film stress

Technical Field

The invention relates to the technical field of semiconductors, in particular to film deposition equipment, and particularly relates to sputtering equipment and a method capable of adjusting film stress.

Background

In the process of manufacturing a semiconductor device, the stress of a deposited film is a problem which needs to be paid attention to, if the stress of the film cannot be controlled within a reasonable range, the film can generate cracks, and even can fall off when the stress is serious, so that the service life of the device is shortened. Therefore, the device has very high requirements on the uniformity of the film, especially on the stress uniformity, the uniformity of the crystal structure and the like of the metal nitride film such as the aluminum nitride film. The most difficult of current stress management is to ensure stress uniformity. The aluminum nitride film deposited by the existing mainstream equipment on the market is adopted, and the stress distribution generally has the conditions of high middle and low two sides. One reason for this is that the aluminum nitride film is deposited at a high temperature (> 350 ℃), a tensile stress is generated during the cooling of the wafer, and the center position is relatively more concentrated, and secondly, a bias voltage is usually used during the deposition of the aluminum nitride film to reduce the tensile stress of the aluminum nitride film to within 100MPa (the tensile stress of the aluminum nitride film is very large, usually >1000 MPa), and in order to effectively reduce the tensile stress, the bias voltage is relatively increased, but after the bias voltage is increased, the plasma concentration distribution in the entire deposition chamber is not uniform, thereby affecting the film thickness and bringing a series of problems such as new stress variation.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention is directed to a sputtering apparatus and method capable of adjusting the stress of a thin film, which is used to solve the problems of the prior art that it is difficult to ensure the stress uniformity of the thin film when depositing the thin film, especially when depositing a metal nitride thin film such as aluminum nitride.

In order to achieve the above and other related objects, the present invention provides a sputtering apparatus capable of adjusting film stress, comprising a chamber, a magnetron sputtering device, a baffle, a wafer press ring, a base and an electromagnetic coil module; the magnetron sputtering device is positioned at the top of the cavity; the baffle is positioned inside the cavity and extends to one side of the base; one end of the wafer pressure ring is adjacent to the baffle, and the other end of the wafer pressure ring extends to the position above the edge of the base; the base is positioned in the cavity and connected with a bias power supply, and a heating unit is arranged in the base; the electromagnetic coil module is positioned in the base and/or between the wafer pressure ring and the base, the electromagnetic coil module comprises a plurality of electromagnetic coil groups, the electromagnetic coil groups are distributed at intervals in the same circumferential plane by taking the center of the cavity as a circle center, the electromagnetic coil groups are mutually electrically isolated, each electromagnetic coil group comprises an N-pole electromagnet and an S-pole electromagnet, the N-pole electromagnets in each electromagnetic coil group are adjacently arranged on the left side of the S-pole electromagnet, and the N-pole magnetic pole surface of the N-pole electromagnet and the S-pole magnetic pole surface of the S-pole electromagnet face upwards or downwards simultaneously; in the sputtering process, the electromagnetic coils are divided into a plurality of electrifying units, and the electrifying units are sequentially and alternately electrified in a clockwise or anticlockwise direction so as to deposit a film on the surface of the substrate and adjust the stress of the film.

Optionally, each of the N-pole electromagnet and the S-pole electromagnet includes a plurality of electromagnetic coils spaced apart from each other and terminals located on both sides of the electromagnetic coils, and the electromagnetic coils are electrically connected to the terminals.

Optionally, the energizing unit includes any one of four forms of a single electromagnetic coil group, two electromagnetic coil groups located on the same diameter, adjacent electromagnetic coil groups, and adjacent or non-adjacent electromagnetic coil groups on multiple diameters.

Optionally, the different sets of solenoids are different lengths.

Optionally, the sputtering apparatus further includes a PLC controller, and all the electromagnetic coil sets are connected to the PLC controller to realize alternate on/off of the energizing unit.

Optionally, the sputtering apparatus further comprises an adapter block, and the baffle comprises an upper baffle and a lower baffle; the adapting block is fixed with the cavity, one end of the upper baffle is fixed between the magnetron sputtering device and the adapting block, and the other end of the upper baffle extends to the periphery of the base; one end of the lower baffle is fixed below the adaptation block, the other end of the lower baffle extends to the bottom of the upper baffle, and one end, far away from the edge of the base, of the wafer pressing ring extends to the upper portion of the lower baffle.

Optionally, a sealing ring is arranged in a gap between the magnetron sputtering device, the upper baffle and the adapting block.

Optionally, a gas inlet is arranged on the side wall of the cavity and located below the baffle, and sputtering gas and reaction gas enter the cavity through the gas inlet; the sputtering device is an aluminum nitride deposition device, the sputtering gas comprises argon, the reaction gas is nitrogen, and the nitrogen overflows and is introduced into the cavity in the sputtering process.

The invention also provides a sputtering method capable of adjusting the film stress, which is carried out according to the sputtering equipment in any scheme, and the sputtering method comprises the steps of dividing the plurality of electromagnetic coils into a plurality of electrifying units in the sputtering deposition process of the film, and sequentially and alternately switching on and off the plurality of electrifying units along the clockwise direction, the anticlockwise direction or the anticlockwise direction so as to deposit the film on the surface of the substrate and adjust the film stress.

Optionally, the sputtering method further comprises the step of adjusting the current magnitude during sputtering to adjust the magnetic field strength generated by each electromagnetic coil group.

Optionally, the deposited film comprises an aluminum nitride film.

As described above, the sputtering apparatus and method capable of adjusting film stress according to the present invention have the following advantages: according to the improved structural design, the electromagnetic coil module is arranged in the base and/or between the wafer press ring and the base, sputtering ions (such as argon ions) near the base can move towards the center of the cavity according to left-hand rules, so that the bombardment effect of the area is enhanced, the tensile stress of the area is reduced, and meanwhile, the concentration of the argon ions going towards the center is adjusted by changing the size of the electrifying current of the electromagnetic coil, so that the bombardment effect on the substrate can be adjusted, the thickness uniformity of a deposited film can be improved, the stress of the deposited film can be adjusted, and the distribution uniformity of the stress can be improved. Meanwhile, in the adjusting process, the magnetic field intensity of the electromagnetic coil can be adjusted by increasing or decreasing the number of turns of a single electromagnetic coil unit, adjusting the current and the like, and in addition, the electromagnetic coil can be increased or decreased at different positions to adjust the area of the aluminum nitride film, such as the area of the aluminum nitride film, which needs to adjust the stress.

Drawings

Fig. 1 is a schematic cross-sectional view of an exemplary sputtering apparatus for adjusting film stress according to the present invention.

Fig. 2 is a schematic diagram illustrating an exemplary top view structure of an electromagnetic coil module in a sputtering apparatus provided in the present invention.

Fig. 3 is a schematic diagram of an exemplary top view configuration of a single solenoid coil group in the solenoid coil module of fig. 2.

Fig. 4 is a schematic diagram of a partial exemplary side view of a single solenoid group in the solenoid module of fig. 2.

Fig. 5 is a schematic diagram of an exemplary top view of the single N-pole electromagnet/S-pole electromagnet of fig. 3.

Fig. 6 is a schematic diagram showing another exemplary top-view structure of the electromagnetic coil module in the sputtering apparatus provided by the present invention.

Description of the element reference numerals

121-a magnetron; 122-a target material; 11-a cavity; 111-an air inlet; 13-upper baffle; 14-a lower baffle; 15-wafer pressure ring; 16-a base; 17-supporting the shaft; 18-a solenoid module; 180-a solenoid coil set; 181-N pole electromagnet; 182-S pole electromagnet; 183-electromagnetic coil; 184-a binding post; 19-an adaptation block; 20-sealing ring.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. As in the detailed description of the embodiments of the present invention, the cross-sectional views illustrating the device structures are not partially enlarged in general scale for convenience of illustration, and the schematic views are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.

For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.

It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated. In order to keep the drawings as concise as possible, not all features of a single figure may be labeled in their entirety.

In the process of film deposition, especially in the process of magnetron sputtering deposition of metal nitride films such as aluminum nitride and the like, due to the influence of deposition conditions such as temperature and/or bias voltage, the stress distribution on the surface of the deposited film is not uniform, so that the film has defects such as cracks and even falling, and the device performance and the service life are seriously influenced. The inventors of the present application have made extensive studies and have proposed an improvement in the long-term work.

Specifically, as shown in fig. 1, the invention provides a sputtering apparatus capable of adjusting film stress, which includes a cavity 11, a magnetron sputtering device, a baffle, a wafer pressing ring 15, a base 16 and an electromagnetic coil module 18; the magnetron sputtering device is located at the top of the chamber 11, and specifically may include a magnetron 121 and a target disk, where the target disk is used to carry a target 122, and during the magnetron sputtering process, the target 122 is connected to a pulse power supply (not shown); the baffle is located inside the cavity 11 and extends to one side of the pedestal 16, namely the baffle covers the inner wall of the cavity 11 between the sputtering device and the pedestal 16 (the space is the sputtering space), and is used for preventing target particles from depositing on the inner wall of the cavity 11 in the sputtering process; the wafer clamping ring 15 has one end adjacent to the baffle plate and the other end extending above the edge of the pedestal 16, more specifically, above the edge of the wafer, for preventing target particles from depositing on the non-coating area of the wafer (which is usually located at the edge of the wafer) during sputtering; the base 16 is located in the cavity 11 and used for bearing a substrate, such as a wafer, the base 16 is connected with a bias power supply, a heating unit is arranged in the base 16, a water cooling unit is also arranged, the bottom of the base 16 is connected with a support shaft 17, the support shaft 17 can extend to the outside of the cavity 11, and power lines, such as power lines and cooling water pipes, can extend from the outside of the cavity 11 to the lower surface of the base 16 through the support shaft 17; the electromagnetic coil module 18 is located in the base 16 and/or between the wafer pressing ring 15 and the base 16, the electromagnetic coil module includes a plurality of (2 and more than 2, preferably more than 3) electromagnetic coil module groups 180, the plurality of electromagnetic coil module groups 180 are distributed at intervals in the same circumferential plane with the center of the cavity 11 as a circle center, and preferably are evenly spaced, one end of each electromagnetic coil module group 180 away from the center of the cavity may be connected to a fixing ring (not labeled), the fixing ring is convenient for being placed to a desired position, the electromagnetic coil module groups 180 are electrically isolated from each other (or are not electrically connected to each other), wherein each electromagnetic coil module group 180 includes an N-pole electromagnet 181 and an S-pole electromagnet 182, the N-pole electromagnet 181 in a single electromagnetic coil module group 180 is adjacently disposed on the left side of the S-pole electromagnet 182 (refer to the direction shown in fig. 2), and the N-pole magnetic pole face of the N-pole electromagnet 181 and the S-pole magnetic pole face of the S-pole electromagnet 182 face upward or downward at the same time (refer to fig. 1, the direction toward the magnetron sputtering apparatus is upward); in the sputtering process, the plurality of solenoid module groups 180 are divided into a plurality of energizing units, and the energizing units are sequentially and alternately energized and de-energized in a clockwise or counterclockwise direction to deposit a thin film on the surface of the substrate and adjust the stress of the thin film. By providing the solenoid module 18, sputtering ions (e.g., argon ions) near the susceptor 16 move toward the center of the chamber 11 according to the left-hand rule, thereby enhancing the bombardment effect of this region, reducing the tensile stress of this region, and adjusting the concentration of argon ions moving toward the center by changing the magnitude of the current to the solenoid 183, thereby adjusting the bombardment effect on the substrate, e.g., on the wafer, adjusting the stress of the deposited film, and improving the stress distribution uniformity. In addition, the magnetic field intensity of the electromagnetic coil 183 can be adjusted by increasing or decreasing the number of turns of the electromagnetic coil 183 and the magnitude of current, and/or the electromagnetic coil 183 can be increased or decreased at different positions to adjust the area of stress needed to be adjusted, such as the aluminum nitride film, the adjusting process is simple and feasible, free and flexible, the magnet is not needed to be demagnetized due to high temperature, and the stability of the device can be ensured.

As shown in fig. 3 to 5, in an example, each of the N-pole electromagnet 181 and the S-pole electromagnet 182 includes a plurality of (e.g., 2 or more) electromagnetic coils 183 spaced apart from each other and terminals 184 located on both sides of the electromagnetic coil 183, the electromagnetic coils 183 are electrically connected to the terminals 184 as needed, each electromagnetic coil 183 is wound around an iron core (not shown) in a circumferential direction, and the electromagnetic coils 183 are magnetized when current is applied; alternatively, it can be described that the N-pole electromagnet 181 and the S-pole electromagnet 182 are each constituted by a row of small electromagnets, and the same magnetic surfaces of the electromagnets located in the same row face in the same direction. The structure can flexibly adjust the number of the access coils, thereby flexibly adjusting the magnetic field intensity according to the requirement.

As an example, the energizing unit includes a single solenoid module group 180, two solenoid module groups 180 located on the same diameter, a plurality of adjacent (2 or more than 2) solenoid module groups 180, and a plurality of adjacent (2 or more than 2) solenoid groups on the diameter, that is, a group of N, S electromagnets 182 is used as a unit, and the energizing is performed first, then the de-energizing is performed, then the energizing is performed in the clockwise or counterclockwise direction to the next group of energizing units, then the de-energizing is performed to the next group, and the above cycle is repeated; or two electromagnetic coil module groups 180 positioned on the same diameter can be used as a power-on unit to be powered on, then the power is cut off, and the power is switched to the next power-on unit in the clockwise or counterclockwise direction, so that the cycle is repeated; or several adjacent or non-adjacent diameters (for example, two or more coil module groups 180 located on any diameter) or several radius coil module groups 180 are used to energize one energizing unit, and then deenergize, and proceed to the next energizing unit clockwise or counterclockwise, and so on. In one example, the sputtering apparatus further includes a PLC controller, and all of the electromagnetic coil module sets 180 are connected to the PLC controller to realize alternate power on and off of the power unit. The provision of the PLC controller facilitates flexible control of the powering on and off of each set of solenoid modules 180, and the PLC controller may also be used to control, for example, the magnetron sputtering apparatus and/or other structures. Of course, in other examples, the central controller of the sputtering apparatus may be used for unified control, which is not strictly limited.

In one example, the sputtering apparatus further comprises an adapter block 19, the shutter including an upper shutter 13 and a lower shutter 14; the adapting block 19 is fixed to the cavity 11, for example, the adapting block 19 can be fixed between the magnetron sputtering device and the cavity 11 and extend into the cavity 11, one end of the upper baffle 13 is fixed between the magnetron sputtering device and the adapting block 19, for example, one end of the upper baffle 13 can be fixed on the top of the adapting block 19, and the other end extends to the periphery of the base 16; one end of the lower baffle plate 14 is fixed below the adapting block 19, the other end of the lower baffle plate extends to the bottom of the upper baffle plate 13, one end of the wafer pressing ring 15, which is far away from the upper side of the edge of the base 16, extends to the upper side of the lower baffle plate 14, for example, the bottom of the lower baffle plate 14 is of a U-shaped structure, and one end of the wafer pressing ring 15 is erected on the U-shaped part. The adaptation block 19 is arranged, so that the height of the adaptation block 19 can be flexibly adjusted, the distance between the magnetron sputtering device and the base 16 is further adjusted, the target base distance is flexibly adjusted according to needs, and the improvement of the film deposition uniformity is facilitated. Of course, to ensure the tightness of the chamber, in one example, a sealing ring 20 is provided in the gap between the magnetron sputtering device, the upper baffle 13 and the adapter block 19.

As an example, the number of the electromagnetic coils and the corresponding iron cores can be increased or decreased at each position according to the process requirement, that is, the number of the electromagnetic coils included in different electromagnetic coil groups can be different, so that the lengths of the different electromagnetic coil groups in the radial direction are different, thereby enhancing or weakening the magnetic field in the area, improving the effect of the Ar ions moving to the center in the area, adjusting the position of the Ar ions bombarding the substrate, improving the film stress deposited in the area, and finally improving the stress uniformity and the film thickness uniformity, and furthermore, adjusting the magnetic field strength by adjusting the number of winding turns of the single electromagnetic coil. The structure of the electromagnetic coil module may be as shown in fig. 6, the electromagnetic coil groups with different lengths are alternately spaced in sequence, or the lengths of the electromagnetic coil groups may be different, or the lengths of the electromagnetic coil groups in each energizing unit are the same, but the lengths of the electromagnetic coil groups in different energizing units are different, which is not strictly limited in this embodiment.

As an example, a gas inlet 111 is disposed on a side wall of the chamber 11, the gas inlet 111 is located below the baffle, and the sputtering gas and the reaction gas enter the inside of the chamber 11 through the gas inlet 111. The gas inlet 111 may be single, and the sputtering gas and the reaction gas enter the cavity 11 through the same gas inlet 111; the number of the gas inlets 111 may also be two or more, and the sputtering gas and the reaction gas enter the cavity 11 through different gas inlets 111, which is not limited in this embodiment. The air outlet of the sputtering apparatus may be correspondingly disposed at a lower portion of the cavity 11 and at a side opposite to the air inlet 111. In one example, the sputtering apparatus is an aluminum nitride deposition apparatus, so the sputtering gas includes argon, and the reaction gas is nitrogen, and because aluminum nitride is deposited at a high temperature, the film stress of the aluminum nitride deposited by the conventional apparatus is large and uneven, and thus the apparatus is particularly suitable for deposition by the sputtering apparatus of the present invention. And nitrogen is overflowed into the cavity 11 in the sputtering process. It should be noted that the term "overflow" means that the amount of the introduced reaction gas is greater than the amount of gas required by the actual sputtering reaction, so that the nitrogen gas will completely fill each space in the chamber and overflow through the gas outlet, which not only can ensure the amount of gas required by the sputtering reaction, but also can purify the inside of the chamber to prevent the external impurity gas from entering the inside of the chamber.

The inventors have verified the sputtering apparatus of the present invention. The verification result shows that under the condition that conditions such as gas flow, temperature and the like are not changed, the sputtering device of the invention is used for depositing the aluminum nitride film with the same thickness (such as 1000 angstroms of the aluminum nitride film), and compared with the sputtering deposition by adopting the existing sputtering device, the stress range (the difference value between the maximum value and the minimum value) of the deposited aluminum nitride film can be reduced from 300MPa to below 150MPa, and the overall stress uniformity can be improved by more than 50%.

The invention also provides a sputtering method capable of adjusting the film stress, which can be carried out according to the sputtering equipment in any scheme. Of course, when the sputtering apparatus with other structure can achieve the required function, the sputtering method can be performed by the sputtering apparatus with other structure, and the present embodiment is not limited strictly, but the sputtering method will be described with reference to the sputtering apparatus described in any of the above embodiments. Specifically, the sputtering method of the present embodiment includes providing the sputtering apparatus described in any of the foregoing embodiments, where the sputtering apparatus is provided with a cavity 11, a target 122, a magnetron 121 required for sputtering the target, and a base 16 with a heating function, and first introducing argon and a reaction gas, nitrogen, into the cavity; applying a pulsed voltage to the target 122, followed by plasma generation, in which a bias voltage is applied to the pedestal 16 and the aforementioned solenoid module 18 is disposed adjacent the pedestal 16; the plurality of electromagnetic coils are divided into a plurality of electrifying units, and the plurality of electrifying units are sequentially and alternately electrified in a clockwise direction or a counterclockwise direction (it is required to be particularly noted that the clockwise direction or the counterclockwise direction is required to be alternately electrified in the process, as the inventor finds that if the two electrifying units are not electrified in the same way, a disturbing magnetic field is generated between an S pole of one electrifying unit and an N pole of the right adjacent electrifying unit, namely, an area between two adjacent electromagnetic coil module groups 180, such as an area A in a dotted line range shown in figures 2 and 6, is an area which is not expected to generate magnetic lines of force, the direction of the magnetic lines of the disturbing magnetic field is just opposite to the direction of the magnetic lines of the magnetic force between the N pole and the S pole in the target electrifying unit, and argon ions are moved to a direction far away from the center, the completely opposite effect is achieved), for example, a group of N, S-pole electromagnets are taken as the electrifying unit, the electrification is firstly carried out and then the power is cut off, then the clockwise or counterclockwise direction is carried out until the next group of electrifying units is electrified and then the power is cut off, and then the next group is carried out, and the process is repeated; or two electromagnetic coil groups on the same diameter are used as one electrifying unit to electrify, then the power is cut off, and the current is conducted to the next electrifying unit in the clockwise or anticlockwise direction, so that the circulation is repeated; or several adjacent or non-adjacent electromagnetic coils with the diameters or the radiuses are used for electrifying one electrifying unit and then are powered off, and the current is conducted to the next electrifying unit in the clockwise or anticlockwise direction, and the process is repeated. The distribution concentration of argon ions in the central area can be adjusted by the magnetic field generated by the electromagnetic coil module, and the thickness uniformity and the stress distribution uniformity of the film can be effectively improved.

In one example, the sputtering method further comprises the step of adjusting the current magnitude in the sputtering process to adjust the magnetic field intensity generated by each electromagnetic coil group, and in addition, the electromagnetic coils can be added and subtracted at different positions to adjust the area of stress required by film deposition, so that the thickness uniformity and stress distribution uniformity of the deposited film can be further improved.

The sputtering method of the invention can be used for depositing various types of films, but is particularly suitable for depositing metal nitride films such as aluminum nitride films, and the more thick the deposited film is (such as more than 3000 nm), the more prominent the advantages of the invention. The sputtering method provided by the invention is adopted to deposit the aluminum nitride film, so that the stress of the aluminum nitride film can be effectively reduced, and the thickness and stress distribution uniformity of the aluminum nitride film are obviously improved.

In summary, the present invention provides a sputtering apparatus and method capable of adjusting film stress. The equipment comprises a cavity, a magnetron sputtering device, a baffle, a wafer pressure ring, a base and an electromagnetic coil module; the magnetron sputtering device is positioned at the top of the cavity; the baffle is positioned inside the cavity and extends to one side of the base; one end of the wafer pressure ring is adjacent to the baffle, and the other end of the wafer pressure ring extends to the position above the edge of the base; the base is positioned in the cavity and connected with a bias power supply, and a heating unit is arranged in the base; the electromagnetic coil module is positioned in the base and/or between the wafer pressure ring and the base, the electromagnetic coil module comprises a plurality of electromagnetic coil groups, the electromagnetic coil groups are distributed at intervals in the same circumferential plane by taking the center of the cavity as a circle center, the electromagnetic coil groups are mutually electrically isolated, each electromagnetic coil group comprises an N-pole electromagnet and an S-pole electromagnet, the N-pole electromagnets in each electromagnetic coil group are adjacently arranged on the left side of the S-pole electromagnet, and the N-pole magnetic pole surface of the N-pole electromagnet and the S-pole magnetic pole surface of the S-pole electromagnet face upwards or downwards simultaneously; in the sputtering process, the electromagnetic coils are divided into a plurality of electrifying units, and the electrifying units are sequentially and alternately electrified in a clockwise or anticlockwise direction so as to deposit a film on the surface of the substrate and adjust the stress of the film. The electromagnetic coil module is creatively arranged in the base and/or between the wafer press ring and the base, sputtering ions (such as argon ions) near the base can move towards the center of the cavity according to left-hand rules, so that the bombardment effect of the area is enhanced, the tensile stress of the area is reduced, and meanwhile, the concentration of the argon ions going towards the center is adjusted by changing the current to the electromagnetic coil, so that the bombardment effect on the substrate can be adjusted, the thickness uniformity of a deposited film can be improved, the stress of the deposited film can be adjusted, and the distribution uniformity of the stress can be improved. Meanwhile, the magnetic field intensity of the electromagnetic coil can be adjusted by increasing or decreasing the number of turns of the electromagnetic coil and adjusting the current in the adjusting process, and in addition, the electromagnetic coil can be increased or decreased at different positions to adjust the area of the aluminum nitride film, such as the area of the aluminum nitride film, which needs to adjust the stress. The invention is especially suitable for depositing the metal nitride film such as aluminum nitride and the like. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims (10)

1. Sputtering equipment capable of adjusting film stress is characterized by comprising a cavity, a magnetron sputtering device, a baffle plate, a wafer pressure ring, a base and an electromagnetic coil module; the magnetron sputtering device is positioned at the top of the cavity; the baffle is positioned inside the cavity and extends to one side of the base; one end of the wafer pressure ring is adjacent to the baffle, and the other end of the wafer pressure ring extends to the position above the edge of the base; the base is positioned in the cavity and connected with a bias power supply, and a heating unit is arranged in the base; the electromagnetic coil module is positioned in the base and/or between the wafer pressure ring and the base, the electromagnetic coil module comprises a plurality of electromagnetic coil groups, the electromagnetic coil groups are distributed at intervals in the same circumferential plane by taking the center of the cavity as a circle center, the electromagnetic coil groups are mutually electrically isolated, each electromagnetic coil group comprises an N-pole electromagnet and an S-pole electromagnet, the N-pole electromagnets in each electromagnetic coil group are adjacently arranged on the left side of the S-pole electromagnet, and the N-pole magnetic pole surface of the N-pole electromagnet and the S-pole magnetic pole surface of the S-pole electromagnet face upwards or downwards simultaneously; in the sputtering process, the electromagnetic coils are divided into a plurality of electrifying units, and the electrifying units are sequentially and alternately electrified in a clockwise or anticlockwise direction so as to deposit a film on the surface of the substrate and adjust the stress of the film.

2. The sputtering apparatus of claim 1 wherein each of said N-pole and S-pole electromagnets includes a plurality of spaced apart electromagnetic coils and posts on either side of the electromagnetic coils, said electromagnetic coils being electrically connected to said posts.

3. The sputtering apparatus according to claim 1, wherein said energizing unit includes any one of three forms of a single said electromagnetic coil group, two said electromagnetic coil groups located on the same diameter, or a plurality of electromagnetic coil groups on non-adjacent diameters.

4. The sputtering apparatus of claim 1 further comprising a PLC controller to which all of said solenoid coil groups are connected to effect alternate on and off powering of the energizing unit.

5. The sputtering apparatus of claim 1, further comprising an adapter block, said baffle comprising an upper baffle and a lower baffle; the adapting block is fixed with the cavity, one end of the upper baffle is fixed between the magnetron sputtering device and the adapting block, and the other end of the upper baffle extends to the periphery of the base; one end of the lower baffle is fixed below the adapting block, the other end of the lower baffle extends to the bottom of the upper baffle, and one end of the wafer pressing ring, which is far away from the upper part of the edge of the base, extends to the upper part of the lower baffle; and sealing rings are arranged in gaps among the magnetron sputtering device, the upper baffle and the adaptation blocks.

6. The sputtering apparatus of claim 2 wherein different sets of electromagnetic coils have different lengths in the radial direction.

7. The sputtering apparatus according to claim 1, wherein a gas inlet is provided on a side wall of the chamber, the gas inlet being located below the baffle plate, and sputtering gas and reaction gas enter the inside of the chamber through the gas inlet; the sputtering device is an aluminum nitride deposition device, the sputtering gas comprises argon, the reaction gas is nitrogen, and the nitrogen overflows and is introduced into the cavity in the sputtering process.

8. A sputtering method capable of adjusting the stress of a thin film, which is carried out by the sputtering device according to any one of claims 1 to 7, wherein the sputtering method comprises the steps of dividing the plurality of electromagnetic coils into a plurality of electrifying units, and sequentially and alternately switching on and off the plurality of electrifying units in a clockwise direction or a counterclockwise direction during the sputtering deposition of the thin film so as to deposit the thin film on the surface of a substrate and adjust the stress of the thin film.

9. The sputtering method of claim 8 further comprising the step of adjusting the amount of current during sputtering to adjust the strength of the magnetic field generated by each set of electromagnetic coils.

10. The sputtering method of claim 8 wherein the deposited film comprises an aluminum nitride film.

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