WO2022267833A1

WO2022267833A1 - Magnetron sputtering assembly, magnetron sputtering apparatus and magnetron sputtering method

Info

Publication number: WO2022267833A1
Application number: PCT/CN2022/095894
Authority: WO
Inventors: 罗建恒; 杨帆; 耿宏伟; 李庆明
Original assignee: 北京北方华创微电子装备有限公司
Priority date: 2021-06-21
Filing date: 2022-05-30
Publication date: 2022-12-29
Also published as: CN113699495B; TW202300680A; TWI828169B; CN113699495A

Abstract

Provided in the present invention is a magnetron sputtering assembly, comprising a rotatable magnetron. The magnetron comprises a plurality of magnetic poles, wherein the orthographic projections of the plurality of magnetic poles on a plane parallel to a surface of a target material are sequentially arranged along a plurality of spiral curves which are mutually nested; and the polarities of the plurality of magnetic poles arranged along any spiral curve are the opposite of the polarities of the plurality of magnetic poles arranged along an adjacent spiral curve, and in the plurality of magnetic poles arranged along any spiral curve, the polarity of at least one magnetic pole located at the center of the curve is the opposite of the polarities of the other magnetic poles. By means of the technical solution provided in the present invention, the uniformity of field intensity distribution of a magnetic field generated by rotation of the magnetron is improved, such that the uniformity of a film deposition rate in a magnetron sputtering reaction is improved. Further provided in the present invention are a magnetron sputtering apparatus and a magnetron sputtering method.

Description

Magnetron sputtering component, magnetron sputtering equipment and magnetron sputtering method

technical field

The present invention relates to the field of semiconductor process equipment, in particular to a magnetron sputtering component, a magnetron sputtering device including the magnetron sputtering component and a magnetron sputtering device applied to the magnetron sputtering device shot method.

Background technique

In recent years, with the rapid development of ultra-large-scale integrated circuit technology, the feature size of electronic devices in the circuit has been continuously reduced, and the device density has been continuously increased. The RC delay (RC Delay, that is, resistance (R), capacitance) The signal delay caused by (C) has become a key factor hindering the performance and speed of ultra-high-density integrated circuits, and reducing RC hysteresis has become the main direction of the semiconductor industry in recent years. In integrated circuit manufacturing, metal lines are usually embedded in an interlevel dielectric (ILD, interlevel dielectric) material with a low dielectric constant. In the Damascus interconnection process, etch stop layers are usually deposited on separate ILD layers and metal lines. It is used in the patterning process of integrated circuit (IC) manufacturing process to protect the material located under these layers from being etched during patterning, while the etch stop layer is usually not completely removed, and as a relatively The thin film between the thick ILD layers remains in the final fabricated semiconductor device. Aluminum oxide (AlO _x ) is used in the advanced process of technology generation below 10 nanometers because of its excellent etch selectivity, good insulation and suitable dielectric constant. The etch stop layer made of AlO _x can be used without While causing the oxidation of the metal layer, it reduces the crosstalk between the metal lines and reduces the RC delay, and protects the underlying porous low-K material (insulating material).

The preparation of AlO _x thin films usually adopts the magnetron sputtering technology in the PVD (Physical Vapor Deposition, physical vapor deposition) process. Compared with the CVD (Chemical Vapor Deposition, chemical vapor deposition) process, the magnetron sputtering technology has good film uniformity. , low impurity, high density and other advantages. The technical generation below 10 nanometers has stricter requirements on the overall performance of the film, and the thickness non-uniformity of the grown film is required to be less than 2%. At the same time, it is necessary to ensure that the composition of the film is uniform to ensure the uniformity of subsequent wet etching and avoid penetration. Phenomenon, improve the product yield of the wafer.

However, when the traditional PVD method uses an aluminum target and oxygen to prepare a non-conductive oxide film by reactive sputtering, the distribution of the magnetic field and the reactive gas is uneven, and it is difficult to meet the thickness uniformity requirements of the technology generation below 10 nanometers for aluminum oxide films. Therefore, how to provide a magnetron sputtering equipment structure capable of improving the uniformity of the thin film prepared by magnetron sputtering technology has become a technical problem to be solved urgently in this field.

Contents of the invention

The present invention aims to provide a magnetron sputtering assembly, a magnetron sputtering device and a magnetron sputtering method, the magnetron sputtering assembly can improve the uniformity of the film deposition rate in the magnetron sputtering reaction, Improve the product yield of the wafer.

In order to achieve the above object, as an aspect of the present invention, a magnetron sputtering assembly in a semiconductor process equipment is provided, including a rotatable magnetron, the magnetron includes a plurality of magnetic poles, and the plurality of magnetic poles are in the Orthographic projections on a plane parallel to the target surface are arranged sequentially along multiple nested helical curves, and the polarity of multiple magnetic poles arranged along any helical curve is different from that of multiple magnetic poles arranged along adjacent helical curves. The polarities of the magnetic poles are opposite, and among the plurality of magnetic poles arranged along any helical curve, the polarity of at least one magnetic pole located at the center of the helical curve is opposite to that of the other magnetic poles.

Optionally, the magnetron sputtering assembly includes a first magnetic pole group and a second magnetic pole group, and the orthographic projection of the plurality of magnetic poles in the first magnetic pole group on a plane parallel to the target surface is along the first The helical curves are arranged in sequence, and the orthographic projections of the plurality of magnetic poles in the second magnetic pole group on a plane parallel to the target surface are arranged in sequence along the second helical curve, and the first helical curve is sleeved on In the second spiral curve, the polarities of the plurality of magnetic poles in the first magnetic pole group are opposite to the polarities of the plurality of magnetic poles in the second magnetic pole group, and in the first magnetic pole group The polarity of at least one magnetic pole located at the center of the first helical curve is opposite to that of the other magnetic poles in the first magnetic pole group, and at least one of the second magnetic pole groups located at the center of the second helical curve The polarity of the pole is opposite to the polarity of the other poles in the second pole set.

Optionally, the first helical curve includes a first sub-curve and a second sub-curve sequentially connected along a direction away from the rotation center of the magnetron, and the second helical curve includes a direction away from the rotation center of the magnetron. The direction of the center of rotation of the controller is connected to the third sub-curve, the fourth sub-curve, and the fifth sub-curve in sequence, the shape of the first sub-curve is consistent with the shape of the third sub-curve, and the first sub-curve The curve and the third sub-curve are arranged symmetrically about the rotation center of the magnetron; the first spiral curve is arranged around the outside of the third sub-curve, and the fifth sub-curve is arranged around the outside of the The outer side of the first spiral curve, the fourth sub-curve bypasses the free end of the second sub-curve, and the two ends of the fourth sub-curve are respectively connected to the third sub-curve and the fifth sub-curve curve.

Optionally, the first sub-curve, the second sub-curve, the third sub-curve and the fifth sub-curve extend helically in a clockwise direction on a plane parallel to the target surface, and the first sub-curve The four sub-curves spirally extend counterclockwise on a plane parallel to the target surface.

Optionally, the polarity of the magnetic pole located at the center of the first spiral curve in the first magnetic pole group is south pole, the polarity of other magnetic poles in the first magnetic pole group is north pole, and in the second magnetic pole group The polarity of the magnetic pole located at the center of the second spiral curve is north pole, and the polarity of other magnetic poles in the second magnetic pole group is south pole.

Optionally, the magnetron sputtering assembly further includes a fixed disk and a rotary drive mechanism, wherein the magnetron is arranged on the fixed disk, and the rotary drive mechanism is connected to the fixed disk for driving The fixed disk rotates about the axis of the fixed disk.

As a second aspect of the present invention, a magnetron sputtering device is provided, including a process chamber and a magnetron sputtering assembly arranged on the process chamber, and the magnetron sputtering assembly is used to provide the A magnetic field is applied in the process chamber, and the magnetron sputtering assembly is the aforementioned magnetron sputtering assembly.

As a third aspect of the present invention, a magnetron sputtering method is provided, which is applied to the magnetron sputtering device as described above, including:

The first process step is to introduce an oxidation sputtering gas into the process chamber;

In the second process step, the oxidation sputtering gas is excited into plasma, and at the same time, the magnetron sputtering assembly is controlled to apply a magnetic field to the process chamber to perform magnetron sputtering to form an oxide film;

In the third process step, a reducing gas is introduced into the process chamber to reduce the oxygen content at the edge of the oxide film.

Optionally, the oxidizing sputtering gas includes oxygen and the reducing gas includes hydrogen.

Optionally, in the third process step, the pressure in the process chamber is greater than or equal to 50 mTorr and less than or equal to 500 mTorr.

Optionally, the first process step, the second process step and the third process step are executed cyclically until the thickness of the oxide film reaches a preset target thickness.

In the magnetron sputtering assembly and magnetron sputtering equipment provided by the embodiments of the present invention, the orthographic projections of multiple magnetic poles on a plane parallel to the target surface are arranged sequentially along multiple helical curves, and along any helical The polarity of the magnetic poles arranged in a curve is opposite to the polarity of the magnetic poles arranged along the adjacent spiral curve. This arrangement along the spiral curve can make the magnetic poles of the same polarity be arranged in a single row no matter in the central area or the edge area. cloth, which improves the uniformity of the field strength distribution of the magnetic field generated by the rotation of the magnetron, and the polarity of at least one magnetic pole located in the center of the helical curve among the magnetic poles arranged along the same helical curve is different from the polarity of other magnetic poles on the same curve On the contrary, the uniformity of the field strength distribution of the magnetic field in the central area of the magnetron is guaranteed, thereby improving the uniformity of the deposition rate of the film in the magnetron sputtering reaction and the uniformity of the thickness of the final film, and improving the product yield of the wafer.

Moreover, in the magnetron sputtering method provided by the present invention, after the oxidized sputtering gas reacts with the target material to generate oxides of the target material, the reducing gas introduced in the third process step can react with the oxygen element in the compound , thereby consuming the oxygen element content in the compound, changing the distribution of oxygen atoms in the film, improving the uniformity of the film components, and further improving the product yield of the chip device on the wafer.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is a kind of structural representation of existing magnetron sputtering equipment;

Fig. 2 is a schematic diagram of the shape of a magnetron in an existing magnetron sputtering device;

Fig. 3 is a schematic diagram of the magnetic pole distribution of the magnetron in the existing magnetron sputtering equipment;

Fig. 4 is a schematic diagram of the magnetic pole distribution of the magnetron in the magnetron sputtering assembly provided by the embodiment of the present invention;

5 is a schematic diagram of the magnetic pole distribution of the magnetron in the magnetron sputtering assembly provided by the embodiment of the present invention;

Fig. 6 is a schematic diagram of the magnetic pole distribution of the magnetron in the magnetron sputtering assembly provided by the embodiment of the present invention;

Fig. 7 is a schematic diagram of corrosion tracks on a target corresponding to a magnetron sputtering assembly provided by an embodiment of the present invention;

Fig. 8 is a schematic diagram comparing the distribution of the magnetic field intensity on the surface of the target with the prior art when the magnetron sputtering device provided by the embodiment of the present invention performs a magnetron sputtering reaction;

Fig. 9 is a schematic diagram comparing the thickness distribution of the film obtained by the magnetron sputtering reaction of the magnetron sputtering equipment provided by the embodiment of the present invention with the prior art;

Fig. 10 is a schematic diagram comparing the thickness distribution of the film obtained by the magnetron sputtering reaction of the magnetron sputtering device provided by the embodiment of the present invention after wet etching and the prior art;

Fig. 11 is the correspondence between the non-uniformity of the film thickness and the loss time of the target material when the magnetron sputtering equipment provided by the embodiment of the present invention and the existing magnetron sputtering equipment perform multiple magnetron sputtering reactions Relationship Diagram;

Fig. 12 is the magnetron sputtering equipment provided by the embodiment of the present invention and the existing magnetron sputtering equipment in which the thickness non-uniformity of the film obtained after wet etching is carried out and the target material Schematic diagram of the corresponding relationship between the lost time;

Fig. 13 is a schematic flowchart of a magnetron sputtering method provided by an embodiment of the present invention.

detailed description

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

Fig. 1 shows a kind of magnetron sputtering equipment that is used for conventional PVD sputtering process, and this equipment comprises process chamber 1, and the cavity of this process chamber 1 is annular, and is arranged in process chamber 1 There is a susceptor 5 (with heating and/or cooling function) for carrying wafers. The vacuum pump system 2 can pump air into the process chamber 1 to make the inside of the process chamber 1 reach a background vacuum higher than 10 ⁻⁶ Torr. The gas source 4 can provide the process gas (such as argon, oxygen, etc.) required for sputtering to the process chamber 1 through the flow meter 3 . The target material 6 (which can be a metal or a metal compound) is arranged on the top of the process chamber 1, and an upper sealing cavity 7 is arranged above the target material 6, and the material of the upper sealing cavity 7 is an insulating material (such as G10 material ), the bottom of the upper sealing chamber 7 is sealed with the target 6, and the upper sealing chamber 7 is filled with deionized water 8.

During the sputtering reaction, the pulsed direct current (DC) power supply applies power to the target 6, so that it has a negative bias voltage relative to the grounded cavity, so that the process gas (such as argon, oxygen, etc.) is ionized and discharged to generate plasma body, and attract positively charged ions to the negatively biased target 6. When the energy of the ions is high enough, metal atoms escape the target surface and deposit on the wafer. The magnetron 9 on the back of the target 6 comprises inner and outer poles with opposite polarities. The motor 12 drives the magnetron 9 to rotate, so as to generate a uniform magnetic field at all angles of the circumference of the process chamber 1, and the sputtering deposition rate is greatly improved through the magnetic field, so as to achieve uniform and efficient deposition of metal oxide films.

Fig. 2 shows the shape of magnetron in a kind of existing magnetron sputtering equipment, and its magnetic pole distribution is as shown in Fig. 3 (solid dot and hollow dot represent two kinds of polarities respectively among Fig. 3, for example, solid The dot represents the South Pole, and the hollow dot represents the North Pole), the inner magnetic pole of the magnetron is the South Pole (S pole), and the outer magnetic pole is the North Pole (N pole). Since the magnetic poles are arranged in double rows near the central area of the inner magnetic pole and the outer magnetic pole, this makes the magnetic field intensity in the central area of the magnetic field generated by the rotation large, and the edge magnetic field intensity is small, resulting in high ion bombardment energy in the central area and high ion bombardment in the edge area. The bombardment energy is low, the deposition rate in the central area of the film is faster than that in the edge area, and the thickness of the film center is larger, which in turn reduces the uniformity of the film thickness on the surface of the film layer. Specifically, as shown in Figure 3, there are gray and white corrosion tracks on the surface of the target, among which, the ring-shaped area between the radius of 58mm-75mm, the radius of 120mm-150mm, and the radius of 210mm-222mm is a light corrosion track, that is, The gray shaded area in 3, the ring-shaped area between the radius of 0mm-58mm, the radius of 75mm-120mm, and the radius of 150mm-210mm is the heavily corroded track, that is, the white area in Figure 3.

In order to solve the above technical problems and improve the thickness uniformity of the film prepared by magnetron sputtering reaction, as one aspect of the present invention, a magnetron sputtering assembly is provided, including a rotatable magnetron. The embodiment of the present invention is used for The structure for driving the magnetron to rotate is not particularly limited. For example, the magnetron can be fixed on the fixed disk; the rotating drive mechanism is connected with the fixed disk to drive the fixed disk to rotate around the axis of the fixed disk. The center of rotation of the tube.

As shown in Figures 4 and 5, the magnetron includes a plurality of magnetic poles (the solid circle pattern and the hollow circle pattern in Figure 4 and Figure 5 respectively indicate that the magnetic poles of two polarities are on a plane parallel to the target surface The orthographic projection of multiple magnetic poles on a plane parallel to the target surface is arranged sequentially along the nested helical curves, and the polarity of multiple magnetic poles arranged along any helical curve is the same as that along the adjacent The polarities of the plurality of magnetic poles arranged in a helical curve are opposite, and the polarity of at least one magnetic pole located at the center of the helical curve among the plurality of magnetic poles arranged along any helical curve is opposite to that of other magnetic poles.

In the present invention, the orthographic projections of multiple magnetic poles on a plane parallel to the surface of the target are arranged sequentially along multiple helical curves, and the polarity of the magnetic poles arranged along any helical curve is the same as that along the adjacent helical curves. The polarity of the magnetic poles is opposite, this way of arrangement along the spiral curve can make the magnetic poles of the same polarity be arranged in a single row no matter in the central area or the edge area (that is, there will not be two rows of magnetic poles with the same polarity at the same time. Extending side by side), the uniformity of the field intensity distribution of the magnetic field generated by the rotation of the magnetron is improved, and the polarity of at least one magnetic pole located at the center of the helical curve among the magnetic poles arranged along the same helical curve is the same as that on the same curve The polarity of the other magnetic poles is opposite, which ensures the uniformity of the field strength distribution of the magnetic field in the central area of the magnetron, thereby improving the uniformity of the deposition rate of the film in the magnetron sputtering reaction and the uniformity of the thickness of the final film, which improves the quality of the wafer. product yield.

As an optional embodiment of the present invention, as shown in Figures 4 to 6, the magnetron sputtering assembly includes a first magnetic pole group and a second magnetic pole group, and a plurality of magnetic poles in the first magnetic pole group are parallel to the target The orthographic projections on the plane of the surface are arranged sequentially along the first helical curve 100, and the orthographic projections of the plurality of magnetic poles in the second magnetic pole group on the plane parallel to the target surface are arranged sequentially along the second helical curve 200, the first The spiral curve 100 is nested in the second spiral curve 200, the polarities of the multiple magnetic poles in the first magnetic pole group are opposite to the polarities of the multiple magnetic poles in the second magnetic pole group, and the first magnetic pole group is located in the first spiral The polarity of at least one magnetic pole at the center of the spiral curve 100 is opposite to that of other magnetic poles in the first magnetic pole group, and the polarity of at least one magnetic pole at the center of the second spiral curve 200 in the second magnetic pole group is opposite to that of the second magnetic pole group. The other poles are opposite in polarity.

The embodiment of the present invention does not specifically limit how the first helical curve 100 and the second helical curve 200 nest with each other, as long as the first magnetic pole group and the second magnetic pole group are evenly distributed, and there will be no single magnetic pole group. The magnetic poles can be distributed in double rows. For example, as an optional embodiment of the present invention, as shown in FIGS. The first sub-curve 110 and the second sub-curve 120 connected successively by the inner circle of the spiral curve to the outer circle), and the second spiral curve 200 includes a direction away from the rotation center of the magnetron (that is, by the spiral curve The third sub-curve 210, the fourth sub-curve 220, and the fifth sub-curve 230 connected successively from the inner circle to the outer circle), the shape of the first sub-curve 110 is consistent with the shape of the third sub-curve 210, and the first sub-curve 110 Set symmetrically with the third sub-curve 210 about the center of rotation of the magnetron; the first helical curve 100 is set around the outside of the third sub-curve 210, and the fifth sub-curve 230 is set around the outside of the first helical curve 100, The fourth sub-curve 220 goes around the free end 120a of the second sub-curve 120 (that is, the end not connected with the first sub-curve 110), and the two ends of the fourth sub-curve 220 are respectively connected to the third sub-curve 210 and the fifth sub-curve 210. Subcurve 230 .

In the embodiment of the present invention, the first spiral curve 100 (including the first sub-curve 110 and the second sub-curve 120 connected in sequence), the third sub-curve 210 and the fifth sub-curve 230 are all helical lines or approximate helical lines , and the rotation directions of the three are the same, the fourth sub-curve 220 connects the third sub-curve 210 and the fifth sub-curve 230 in a smooth transition. The first helical curve 100 corresponding to the first magnetic pole group is arranged around the outside of the third sub-curve 210 corresponding to the second magnetic pole group, and the fifth sub-curve 230 corresponding to the second magnetic pole group is arranged around the first helical curve 100 Therefore, multiple magnetic poles of the same polarity at any position are arranged in a single row, and the uniformity of the field strength distribution of the magnetic field generated by the rotation of the magnetron is improved through the single row arrangement.

The embodiment of the present invention does not specifically limit the angles at which the first spiral curve 100, the third sub-curve 210, and the fifth sub-curve 230 extend around the center of the fixed disk, for example, optionally, as shown in Figures 5 and 6 , the first helical curve 100 and the fifth sub-curve 230 circle around the rotation center of the magnetron for one circle, and the third sub-curve 210 circles the magnetron's rotation center for half a circle. That is, the two ends of the first spiral curve 100, the outer end of the third sub-curve 210 and the two ends of the fifth sub-curve 230 are located on the same side of the rotation center of the magnetron, and the two ends of the third sub-curve 210 are respectively Located on opposite sides of the center of rotation of the magnetron.

The embodiment of the present invention does not specifically limit the helical extension direction of the first helical curve 100 and the second helical curve 200 on the fixed disk. For example, optionally, as shown in FIGS. 4 to 6 , the first sub-curve 110, the second sub-curve 120, the third sub-curve 210 and the fifth sub-curve 230 spirally extend clockwise on a plane parallel to the surface of the target (for example, in a top view direction), and the fourth sub-curve 220 is parallel to the target surface On the plane of the surface (for example, the top view direction), it extends helically in a counterclockwise direction.

The embodiment of the present invention does not specifically limit the polarity of the magnetic poles in the first magnetic pole group and the second magnetic pole group, for example, optionally, the polarity of at least one magnetic pole located in the center of the first spiral curve 100 in the first magnetic pole group is the south pole (as shown by the solid circle pattern in the figure), the polarity of other magnetic poles in the first magnetic pole group is the north pole (that is, as shown by the circle pattern in the figure), and the polarity of the second magnetic pole group located in the center of the first spiral curve 100 The polarity of at least one magnetic pole is north pole, and the polarity of other magnetic poles in the second magnetic pole group is south pole.

Compared with the existing magnetron, the magnetic field distribution of the magnetron in the magnetron sputtering assembly provided by the embodiment of the present invention is more uniform in the energy distribution of the ions sputtered from the corresponding target in the central area of the wafer, and the effect is as follows: As shown in FIG. 8 (the horizontal axis represents the wafer radius (from -R to +R, for example, when the wafer radius is 150mm, the horizontal axis is -150mm to +150mm), and the vertical axis represents the magnetic field strength).

When the magnetron sputtering assembly provided by the embodiment of the present invention is used to provide a magnetic field to the target, the corrosion track formed on the surface of the target after the sputtering reaction is shown in Figure 4 to Figure 7, and the surface of the target has gray and white corrosion tracks , where the ring-shaped area between the radius 35mm-50mm, the radius 95mm-115mm, and the radius 140mm-150mm is a lightly corroded track, that is, the gray shaded area in Figure 7, the radius is 0mm-35mm, the radius is 50mm-95mm, and the radius is 115mm The ring-shaped area between -140mm is the heavily corroded track, that is, the white part area in Figure 7. The magnetron sputtering assembly provided by the embodiment of the present invention changes the magnetic field intensity distribution on the target surface, changes the corrosion track distribution on the target surface, thereby changes the ion distribution and energy distribution in the film forming process, and changes the thickness of the film. The distribution trend improves the uniformity of the film thickness distribution in the magnetron sputtering reaction.

As a second aspect of the present invention, a magnetron sputtering device is provided, including a process chamber and a magnetron sputtering assembly arranged above the process chamber, the magnetron sputtering assembly is used to apply a magnetic field to the process chamber , wherein the magnetron sputtering assembly is the magnetron sputtering assembly provided by the embodiment of the present invention.

In the magnetron sputtering equipment provided by the present invention, the orthographic projections of multiple magnetic poles on a plane parallel to the surface of the target are arranged sequentially along a plurality of helical curves, and the polarity of the magnetic poles arranged along any helical curve is the same as The polarity of the magnetic poles arranged along the adjacent spiral curves is opposite. This way of arrangement along the spiral curves can make the magnetic poles of the same polarity be arranged in a single row no matter in the central area or the edge area, which improves the rotation of the magnetron. The field intensity distribution of the generated magnetic field is uniform, and the polarity of at least one magnetic pole located in the center of the helical curve among the magnetic poles arranged along the same helical curve is opposite to that of other magnetic poles on the same curve, ensuring that the magnetron center The uniformity of the field strength distribution of the regional magnetic field further improves the uniformity of the film deposition rate in the magnetron sputtering reaction and the thickness uniformity of the final film, which improves the product yield of the wafer.

As a third aspect of the present invention, a magnetron sputtering method is provided, which is applied to the magnetron sputtering equipment provided in the embodiment of the present invention, as shown in Figure 13, the method includes:

In the first process step S1, the oxidation sputtering gas is introduced into the process chamber;

In the second process step S2, the oxidation sputtering gas is excited into plasma, and at the same time, the magnetron sputtering component is controlled to apply a magnetic field to the process chamber to perform magnetron sputtering to form an oxide film;

In the third process step S3, a reducing gas is introduced into the process chamber to reduce the oxygen content at the edge of the oxide film.

The magnetron sputtering method provided by the present invention is realized by the magnetron sputtering device provided by the embodiment of the present invention. In the magnetron sputtering device, the orthographic projections of multiple magnetic poles on a plane parallel to the target surface are along multiple helical The magnetic poles arranged along any helical curve are arranged in sequence, and the polarity of the magnetic poles arranged along any helical curve is opposite to that of the magnetic poles arranged along the adjacent helical curve. In the central area or the edge area, they are all arranged in a single row, which improves the uniformity of the field intensity distribution of the magnetic field generated by the rotation of the magnetron, and, among the magnetic poles arranged along the same helical curve, at least one magnetic pole located in the center of the helical curve The polarity is opposite to that of other magnetic poles on the same curve, which ensures the uniformity of the field strength distribution of the magnetic field in the central area of the magnetron, thereby improving the uniformity of the film deposition rate in the magnetron sputtering reaction and the final thickness of the film performance, improving the product yield of the wafer.

Moreover, in the magnetron sputtering method provided by the present invention, after the oxidized sputtering gas reacts with the target material to generate oxides of the target material, the reducing gas introduced in the third process step S3 can interact with the oxygen element in the compound. reaction, thereby consuming the oxygen element content in the compound, changing the distribution of oxygen atoms in the film, and improving the uniformity of film components (in physical vapor deposition process equipment, the process chamber is generally edge-intake, step S3 The reaction rate of the reducing gas with the oxide in the edge area is higher than that with the oxide in the center area, thereby further reducing the difference in oxygen content between the edge area and the center area, improving the uniformity of oxygen content), and improving the on-wafer The product yield of the chip device.

In some embodiments of the present invention, for example, when it is necessary to form an oxide film with a thickness of more than 10 nanometers, the first process step S1, the second process step S2 and the third process step S3 can be performed cyclically until the thickness of the oxide film is Reach the preset target thickness.

As an optional embodiment of the present invention, the oxidizing sputtering gas may include oxygen, and the reducing gas may include hydrogen. After the oxidizing sputtering gas oxidizes the metal target to generate the metal oxide of the target metal, for example, after the oxygen alumina target generates aluminum oxide (AlO _x ), maintain the process pressure of the chamber and the temperature state of the carrier plate, and Introduce hydrogen into the process chamber, and use the reducing property of hydrogen to change the distribution of oxygen atoms in the film to achieve secondary oxidation, reduce the oxygen content at the edge of the film, and improve the uniformity of the film components.

In some embodiments of the present invention, the oxidizing sputtering gas may further include an inert gas, for example, the oxidizing sputtering gas may include oxygen and argon (Ar).

In order to adapt to the process requirements of different types of oxide films, preferably, the reducing gas can also be a mixed gas, for example, the reducing gas can include hydrogen and oxygen. In the third process step S3, for different types of oxide films, by Adjusting the composition ratio between hydrogen and oxygen changes the reducing ability of the reducing gas, so as to precisely control the reduction reaction rate at the edge of the film.

The embodiment of the present invention does not specifically limit the pressure inside the process chamber in each process step. For example, as an optional implementation of the present invention, in the first process step S1, the pressure in the process chamber is 3-20 mTorr ; In the third process step S3, the pressure in the process chamber is greater than or equal to 50mTorr and less than or equal to 500mTorr (preferably 200mTorr).

The embodiment of the present invention improves the performance and process stability of the entire thin film through the collaborative optimization of the process method. As shown in Figure 9, when the magnetron sputtering assembly provided by the embodiment of the present invention is used to provide a magnetic field to the target, the thickness of the central region of the film formed after the target undergoes a sputtering reaction decreases, and such a thickness distribution profile is more favorable Increase the process rate of the central region in the subsequent wet etching process (Figure 10 shows the thickness distribution of the film layer obtained after wet etching with the deposited film).

As shown in Figure 11, the unevenness of the thickness of the film obtained by the sputtering reaction using the magnetron sputtering scheme provided by the embodiment of the present invention is less than 2%, as shown in Figure 12, the thickness of the film layer is obtained by subsequent wet etching The unevenness is less than 3%, and the key process indicators such as the uniformity of the film composition have also been greatly improved. In addition, because the corrosion rate of the target is more uniform in the magnetron sputtering reaction, the life of the target is also improved. In order to improve, the magnetron sputtering solution provided by the embodiment of the present invention can increase the target life from 700 kWh to 2000 kWh, reduce the process cost of magnetron sputtering reaction, and improve the overall performance of the equipment.

For the convenience of those skilled in the art to understand, the present invention also provides a kind of specific embodiment of above-mentioned process step:

The first step (first process step S1), control the lifting of the carrier plate to the process position, and pass _O2 (or the mixed gas of Ar and _O2 ), the flow rate of O2 is 0-500sccm (preferably 50-200sccm, the flow rate of Ar 0-500 sccm, preferably 0-200 sccm), the pressure in the process chamber is maintained at 3-20 mTorr.

In the second step (second process step S2), keep the pressure in the process chamber constant, control the magnetron sputtering assembly to provide a magnetic field to the target in the process chamber, and control the DC power supply (DC) to provide DC to the target Voltage, using the plasma to bombard the surface of the target, the aluminum atoms and oxygen atoms react on the wafer surface to form an AlO _x film (DC power is 0-20000W, preferably 1000-10000W).

In the third step (the third process step S3), continue to feed H ₂ (or the mixed gas of O ₂ and H ₂ ), the pressure in the process chamber is maintained at 50-500mTorr (preferably 200mTorr), and the carrier plate is at In the high temperature state, _H2 is used to change the distribution of oxygen atoms in the film.

It should be noted that the magnetron sputtering scheme provided in the embodiment of the present invention is not only applicable to the process of forming AlO _x thin film, but also applicable to the magnetron sputtering reaction of other material thin films, for example, titanium dioxide (TiO ₂ ), Silicon (SiO ₂ ), hafnium oxide (HfO), tantalum oxide (TaO), titanium oxynitride (TiON), silicon oxynitride (SiON), hafnium oxynitride (HfON), tantalum oxynitride (TaON), etc. .

It can be understood that, the above embodiments are only exemplary embodiments adopted for illustrating the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered as the protection scope of the present invention.

Claims

A magnetron sputtering assembly in semiconductor process equipment, including a rotatable magnetron, characterized in that the magnetron includes a plurality of magnetic poles, and the plurality of magnetic poles are on a plane parallel to the target surface Orthographic projections are arranged sequentially along multiple nested spiral curves, and the polarity of multiple magnetic poles arranged along any spiral curve is opposite to that of multiple magnetic poles arranged along adjacent spiral curves, and along any Among the plurality of magnetic poles arranged in a spiral curve, at least one magnetic pole located at the center of the spiral curve has a polarity opposite to that of other magnetic poles.
The magnetron sputtering assembly according to claim 1, wherein the magnetron sputtering assembly comprises a first magnetic pole group and a second magnetic pole group, and a plurality of the magnetic poles in the first magnetic pole group are parallel The orthographic projections on the plane of the target surface are arranged sequentially along the first helical curve, and the orthographic projections of the plurality of magnetic poles in the second magnetic pole group on the plane parallel to the target surface are arranged along the second helical curve in sequence;

The first spiral curve is nested in the second spiral curve, and the polarities of the plurality of magnetic poles in the first magnetic pole group are the same as the polarities of the plurality of magnetic poles in the second magnetic pole group On the contrary, and the polarity of at least one magnetic pole located in the center of the first spiral curve in the first magnetic pole group is opposite to that of other magnetic poles in the first magnetic pole group, and the polarity of the second magnetic pole group located in the center of the first spiral curve The polarity of at least one magnetic pole at the center of the second spiral curve is opposite to that of other magnetic poles in the second magnetic pole group.
The magnetron sputtering assembly according to claim 2, wherein the first helical curve comprises a first sub-curve and a second sub-curve sequentially connected in a direction away from the rotation center of the magnetron, The second spiral curve includes a third sub-curve, a fourth sub-curve, and a fifth sub-curve sequentially connected in a direction away from the rotation center of the magnetron, and the shape of the first sub-curve is the same as that of the first sub-curve. The shapes of the three sub-curves are consistent, and the first sub-curve and the third sub-curve are symmetrically arranged about the rotation center of the magnetron; the first spiral curve is arranged around the third sub-curve On the outside, the fifth sub-curve is arranged around the outside of the first spiral curve, the fourth sub-curve goes around the free end of the second sub-curve, and the two ends of the fourth sub-curve are respectively connecting the third sub-curve and the fifth sub-curve.
The magnetron sputtering assembly according to claim 3, wherein the first sub-curve, the second sub-curve, the third sub-curve and the fifth sub-curve are parallel to the target surface On the plane of , the fourth sub-curve extends helically in the counterclockwise direction on the plane parallel to the target surface.
The magnetron sputtering assembly according to any one of claims 2 to 4, wherein the polarity of at least one magnetic pole located at the center of the first helical curve in the first magnetic pole group is a south pole, so The polarity of the other magnetic poles in the first magnetic pole group is the north pole, the polarity of at least one magnetic pole located in the center of the second spiral curve in the second magnetic pole group is the north pole, and the other magnetic poles in the second magnetic pole group Polarity is South Pole.
The magnetron sputtering assembly according to any one of claims 2 to 4, wherein the magnetron sputtering assembly further comprises a fixed disk and a rotary drive mechanism, wherein the magnetron is arranged on the On the fixed disk, the rotation driving mechanism is connected with the fixed disk and is used to drive the fixed disk to rotate around the axis of the fixed disk.
A magnetron sputtering device, comprising a process chamber and a magnetron sputtering assembly arranged on the process chamber, the magnetron sputtering assembly is used to apply a magnetic field to the process chamber, characterized in that , the magnetron sputtering assembly is the magnetron sputtering assembly described in any one of claims 1-6.
A magnetron sputtering method, applied to the magnetron sputtering device as claimed in claim 7, characterized in that, comprising:

The first process step is to introduce an oxidation sputtering gas into the process chamber;

The second process step is to excite the oxidized sputtering gas into plasma, and simultaneously control the magnetron sputtering assembly to apply a magnetic field to the process chamber to perform magnetron sputtering to generate an oxide film;

In the third process step, a reducing gas is introduced into the process chamber to reduce the oxygen content at the edge of the oxide film.
The magnetron sputtering method according to claim 8, wherein the oxidizing sputtering gas includes oxygen, and the reducing gas includes hydrogen.
The magnetron sputtering method according to claim 8, characterized in that, in the third process step, the pressure in the process chamber is greater than or equal to 50 mTorr and less than or equal to 500 mTorr.
The magnetron sputtering method according to claim 8, wherein the first process step, the second process step and the third process step are cyclically executed until the thickness of the oxide film reaches a predetermined value. set target thickness.