CN113249702B

CN113249702B - Magnetron sputtering equipment for improving cleanliness of magnetron sputtering environment

Info

Publication number: CN113249702B
Application number: CN202110765236.4A
Authority: CN
Inventors: 潘钱森; 周云; 宋维聪
Original assignee: Bitong Semiconductor Equipment Suzhou Co ltd
Current assignee: Bitong Semiconductor Equipment Suzhou Co ltd
Priority date: 2021-07-07
Filing date: 2021-07-07
Publication date: 2021-10-22
Anticipated expiration: 2041-07-07
Also published as: CN113249702A

Abstract

The invention provides a magnetron sputtering device for improving the cleanliness of a magnetron sputtering environment, which comprises: the device comprises a permanent magnet device, a target back plate, an adapting block, an upper baffle, a lower baffle, a wafer base and a cavity; the upper baffle is arranged in the cavity along the circumferential direction; the upper baffle plate comprises a flanging, an inclined part and a first extending part which are integrally formed from top to bottom, wherein the upper baffle plate is installed on the adaptation block through the flanging, the inclined part is consistent with the inclination angle of the side face of the target material, the first extending part extends from the edge of the cavity to the center of the cavity, and the projection of the first extending part in the transverse direction covers the ineffective sputtering area at the edge of the target material. Through setting up the overhead gage, can effectively block the piling up of stress film layer in non-effective sputtering region to effectively avoided non-effective sputtering region to lead to stress film layer fracture or even drop the problem that produces the particle because stress film layer piles up gradually, can also block the particle that non-effective sputtering region produced simultaneously and enter into to sputter the operational environment.

Description

Magnetron sputtering equipment for improving cleanliness of magnetron sputtering environment

Technical Field

The invention relates to the technical field of semiconductor manufacturing equipment, in particular to magnetron sputtering equipment for improving the cleanliness of a magnetron sputtering environment.

Background

With the development of semiconductor technology, various devices have appeared, and different semiconductor materials have appeared. Many of these materials have higher stresses, which leads to higher requirements for film properties due to the advanced manufacturing processes, which involve particle problems of the film.

At present, the film with larger stress prepared by the PVD method is mainly made of metal nitride, and the production process can adopt a radio frequency sputtering method and a reactive sputtering method. In the sputtering coating process, certain active reaction gas is introduced in an artificial control mode, reacts with sputtered target particles and then is deposited on a substrate, and a film different from a metal target can be obtained. For example, by passing N during sputtering₂The nitride is obtained by reactive sputtering as a reactive gas. Because the stress of the film layers is larger, more and more corresponding film layers can be deposited on the hardware inside the sputtering equipment and the surface of the target material, particularly the edge of the target material after long-time work, and because the film layers are thickened and the stress of the film layers is larger, the film layers begin to crack or even fall off after working for a certain time, film layer particles are generated in the process, and the film layer particles are generatedThe particles falling onto the coating will affect the properties of the coating.

In order to effectively reduce the influence of the film layer particles on the coating layer, the generation of the particles is mainly reduced by the following schemes: firstly, after the magnetron sputtering equipment works for a period of time, a PK part in the equipment, such as an upper baffle, a lower baffle or a wafer compression ring, can be replaced, and particles caused by a stress film layer deposited by the PK part in the equipment can be avoided by replacing the PK part; secondly, after the magnetron sputtering equipment works for a period of time, a certain number of dummy sheets are prepared, and the stress film layer deposited on the PK part is covered by metal by simply sputtering the metal target material, so that the stress film layer is prevented from cracking to generate particles in the production process.

However, the above-mentioned scheme for reducing particle generation leaves a place, and the non-effective sputtering region (i.e. the edge of the target and the sidewall of the target) having a large stress film cannot be effectively removed. Because the magnetron sputtering principle is that closed magnetic lines of force are arranged on the surface of the target material, an effective sputtering area is generated, the second scheme can remove a film layer with larger stress on the surface of the target material by sputtering pure metal, but the effect cannot be effectively generated in a non-effective sputtering area, so that the stress film layer is continuously accumulated in the non-effective sputtering area, and finally, the film layer is cracked and even falls off due to the thickening and the increasing of the film layer, so that the environment of the whole cavity and the quality of the deposited film layer are influenced. Even if the magnet is moved towards the edge of the target to make the closed magnetic lines cover the edge of the target, the film on the wall of the target cannot be sputtered off in this way because the area between the side wall of the target and the upper baffle is a dark area with glow, which is not generated, and naturally, the sputtering effect cannot be generated.

Disclosure of Invention

In view of the above drawbacks of the prior art, an object of the present invention is to provide a magnetron sputtering apparatus for improving cleanliness of a magnetron sputtering environment, so as to solve the problem that in a sputtering process of the magnetron sputtering apparatus in the prior art, a stress film layer generated in a non-effective sputtering region of a target material gradually accumulates to cause cracking of the stress film layer, even fall off to generate particles, and the like.

To achieve the above and other related objects, the present invention provides a magnetron sputtering apparatus for improving cleanliness of a magnetron sputtering environment, including: the device comprises a permanent magnet device, a target back plate, an adapter block, an upper baffle, a lower baffle, a wafer base and a cavity, wherein the target back plate is positioned above the target, and the permanent magnet device is positioned above the target back plate;

the upper baffle is circumferentially arranged inside the cavity and is used for improving the cleanliness of the magnetron sputtering environment; the upper baffle plate comprises a flanging, an inclined part and a first extending part which are integrally formed from top to bottom, wherein the upper baffle plate is installed on the adaptation block through the flanging, the inclined part is consistent with the inclination angle of the side face of the target, the first extending part extends from the edge of the cavity to the center of the cavity, and the projection of the first extending part in the transverse direction covers the ineffective sputtering area at the edge of the target.

Optionally, the first extension extends in a transverse direction towards the center of the cavity or extends obliquely upwards from the edge of the cavity towards the center of the cavity.

Optionally, a starting end of the first extension portion is connected to an end of the inclined portion.

Optionally, the upper baffle further comprises a second extension part, and the second extension part extends from the upper part to the lower part of the cavity along the vertical direction; the end of the first extension part is connected with the beginning of the second extension part, or the inclined part is connected with the second extension part, and the first extension part is connected with the inclined part or the second extension part.

Optionally, the projection length of the first extension part in the transverse direction is between 3mm and 10 mm.

Optionally, the distance between the projection of the first extension part in the transverse direction and the surface of the target is between 2mm and 3 mm.

Optionally, the distance between the inclined part and the side surface of the target is between 2mm and 3 mm.

Optionally, one side of the upper baffle plate facing the inside of the cavity is a sand blasting surface or a melting and jetting surface.

Optionally, the upper baffle plate is made of stainless steel or titanium.

Optionally, the magnetron sputtering apparatus further includes: the wafer clamping ring, the wafer clamping ring evenly is provided with the circular port along circumference, the quantity of circular port is between 16 ~32, the diameter of circular port is between 15mm ~30 mm.

As described above, according to the magnetron sputtering device for improving the cleanliness of the magnetron sputtering environment, the upper baffle is arranged, the first extension part of the upper baffle is combined with the inclined part to cover the ineffective sputtering area of the target, the accumulation of the stress film layer on the ineffective sputtering area of the target is effectively prevented in the magnetron sputtering process, the stress film layer is formed in the ineffective sputtering area of the target as little as possible, the stress film layer is deposited on the upper baffle, and the upper baffle as a PK component only needs to be replaced periodically, so that the problem that the stress film layer cracks or even falls off to generate particles due to the gradual accumulation of the stress film layer in the ineffective sputtering area of the target is effectively solved, and the upper baffle can also prevent the particles generated in the ineffective sputtering area of the target from entering the sputtering working environment.

Drawings

Fig. 1 and fig. 2 are schematic structural diagrams of a magnetron sputtering apparatus for improving the cleanliness of a magnetron sputtering environment according to the present invention.

Fig. 3 to fig. 10 are schematic structural diagrams of an upper baffle plate in a magnetron sputtering device for improving the cleanliness of a magnetron sputtering environment according to the present invention.

Fig. 11 is a schematic structural diagram of a wafer pressure ring in a magnetron sputtering apparatus for improving the cleanliness of a magnetron sputtering environment according to the present invention.

Fig. 12 is a schematic cross-sectional view taken along direction AA in fig. 11.

Description of the element reference numerals

The sputtering device comprises a permanent magnet device 10, a target 11, a target backing plate 12, an adapter block 13, an upper baffle 14, a flanging 140, an inclined part 141, a first extending part 142, a second extending part 143, a lower baffle 15, a wafer base 16, a cavity 17, a wafer press ring 18, a circular hole 180, a sealing ring 19, an air port 20, a wafer 21 and an ineffective sputtering area A.

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.

Please refer to fig. 1 to 12. 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 drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of each component in actual implementation may be changed according to actual needs, and the layout of the components may be more complicated.

As described in the background art, the methods for controlling particles generated during the magnetron sputtering process in the prior art mainly include periodically replacing PK components and covering a stress film with a metal film, but the inventors have recognized that the two methods have a common problem that the stress film is formed by continuously depositing the edges of the target material and the non-effective sputtering region of the side wall of the target material, and the film cracks and even falls off as the film becomes thicker and the stress becomes stronger, so that further improvement of the cleanliness of the magnetron sputtering environment is limited.

Based on the above knowledge, the inventors propose a magnetron sputtering apparatus for improving the cleanliness of a magnetron sputtering environment from the viewpoint of effectively preventing the stress film layer from being continuously deposited in the non-effective sputtering area of the target, as shown in fig. 1 to 10, and the magnetron sputtering apparatus includes: the device comprises a permanent magnet device 10, a target 11, a target back plate 12, an adapting block 13, an upper baffle plate 14, a lower baffle plate 15, a wafer 16 and a cavity 17, wherein the target back plate 12 is positioned above the target 11, and the permanent magnet device 10 is positioned above the target back plate 12;

the upper baffle 14 is circumferentially arranged inside the cavity 17 and is used for improving the cleanliness of the magnetron sputtering environment; the upper baffle 14 includes a flange 140, an inclined portion 141, and a first extension 142 integrally formed from top to bottom, wherein the upper baffle 14 is mounted on the adapter block 13 through the flange 140, the inclined portion 141 and the side surface of the target 11 have the same inclination angle, the first extension 142 extends from the edge of the cavity 17 to the center of the cavity 17, and the projection of the first extension 142 in the transverse direction covers the inactive sputtering area a of the edge of the target 11.

It should be noted here that the main structure of the magnetron sputtering apparatus of the present embodiment is the conventional structure, so the connection manner between these structures is not described in detail here, and in addition, other conventional structures may also be included, for example: a seal ring 19; gas ports 20, one of which 20 is for the inlet of process gas and the other 20 is for the pump gas port; the wafer susceptor 16 is provided therein with a heater (not shown) and the like.

For the convenience of direction understanding, as shown in fig. 1 and fig. 2, in the present embodiment, a magnetron sputtering apparatus is used as a reference target, and a transverse direction X is defined as a left-right direction of the magnetron sputtering apparatus, and a vertical direction Y is defined as an up-down direction of the magnetron sputtering apparatus.

The magnetron sputtering device of the embodiment, through setting up the upper shield 14, the first extension part 142 of the upper shield 14 is combined with the inclined part 141 together to cover the inactive sputtering area a of the target 11, in the magnetron sputtering process, effectively block the accumulation of the stress film layer in the inactive sputtering area a of the target 11, make the inactive sputtering area a of the target 11 form the stress film layer as little as possible, make the stress film layer deposit on the upper shield 14, and the upper shield 14 only needs to be changed regularly as the PK piece, thereby effectively avoiding the problem that the stress film layer cracks or even falls off to generate particles because the stress film layer is gradually accumulated in the inactive sputtering area a of the target 11, and the upper shield 14 can also block the particles generated in the inactive sputtering area a of the target 11 from entering into the sputtering working environment.

As shown in fig. 1, 3 to 7, as an example, the first extension 142 extends toward the center of the cavity 17 along the transverse direction X; alternatively, as shown in fig. 8 to 10, the first extending portion 142 may also extend obliquely upward from the edge of the cavity 17 to the center of the cavity 17. In this embodiment, it is preferable that the first extending portion 142 extends from the edge of the cavity 17 to the center of the cavity 17 in an inclined manner, and since the first extending portion 142 is inclined upward and has a steep slope with respect to the stress film layer stacked thereon, particles are more difficult to fall into the sputtering environment.

As shown in fig. 3 and 8, the top baffle 14 includes, as an example, a flange 140, an inclined portion 141, and a first extending portion 142 integrally formed from top to bottom, and a start end of the first extending portion 142 is connected to an end of the inclined portion 141.

As shown in fig. 4 to 7 and 9 to 10, the upper baffle 14 may further include a second extension 143, in addition to the flange 140, the inclined portion 141 and the first extension 142, and the second extension 143 may extend from an upper portion of the cavity 17 to a lower portion thereof in a vertical direction. The connection manner of the second extension portion 143, the first extension portion 142 and the inclined portion 141 may be set according to actual needs, for example, as shown in fig. 7 and 10, the end of the first extension portion 142 is connected to the start end of the second extension portion 143; as shown in fig. 4 to 6 and 9, the inclined portion 141 is connected to the second extending portion 143, and the first extending portion 142 is connected to the inclined portion 141 or the second extending portion 143.

As shown in fig. 3 and 8, the projection length L of the first extension portion 142 in the transverse direction is between 3mm and 10mm, but is not limited thereto, and is specifically selected according to the size of the non-effective sputtering area a at the edge of the target 11.

As shown in fig. 1 and 2, for example, a distance D1 between a projection of the first extension portion in the transverse direction and the target surface is between 2mm and 3 mm. When the value of D1 is smaller than this range, arc discharge is generated between the target 11 and the first extension 142, which affects the sputtering effect; when the value of D1 is larger than this range, plasma is generated between the target 11 and the first extension 142, and the plasma bombards the target backing plate 12, causing the target backing plate material to enter the sputtered film layer, forming impurities.

As shown in fig. 1 and 2, a distance D2 between the inclined portion 141 and the side surface of the target 11 is, for example, 2mm to 3 mm. When the value of D2 is smaller than this range, arc discharge is generated between the target 11 and the inclined portion 141, which affects the sputtering effect; when the value of D2 is larger than this range, plasma is generated between the target 11 and the inclined portion 141, and the plasma bombards the target backing plate 12, causing the target backing plate material to enter the sputtered film layer, forming impurities.

As shown in fig. 1 and fig. 2, as an example, a surface of the upper baffle 14 facing the inside of the cavity 17 (i.e., a sputtering film deposition surface) may be roughened to improve adhesion of the upper baffle to a sputtering stress film and to prolong a replacement cycle of the upper baffle. The surface roughening treatment includes sand blasting, melting and jetting, etc.

The material of the upper baffle plate 14 can be specially set according to specific sputtering requirements, and a conventional baffle plate material suitable for magnetron sputtering, such as stainless steel or titanium, can be selected.

As shown in fig. 11 and 12, as an example, the magnetron sputtering apparatus of the present embodiment further includes a wafer pressing ring 18, and the wafer pressing ring 18 is uniformly provided with circular holes 180 along a circumferential direction, the number of the circular holes 180 is between 16 and 32, and the diameter of the circular holes 180 is between 15mm and 30 mm. As shown in fig. 12, the wafer chuck 18 is a hollow structure, and particles generated during the sputtering process will enter the hollow structure of the wafer chuck 18, so that the particles will not be accumulated near the wafer (i.e. in the glow generating region) to affect the environment of the whole process chamber and thus affect the wafer coating quality.

The inventors conducted experiments on the number of the circular holes 180 in the wafer pressing ring 18 and the selection of the diameter of the circular holes 180 using these two parameters as variables, and the results of the experiments are shown in tables 1 and 2, according to the comparison between the experimental results and the grain data of the structure of the circular hole 180 of the wafer pressing ring 18 not used in the embodiment, the number of grains of the structure of the circular hole 180 of the wafer pressing ring 18 not used in the embodiment is 16 grains > 0.16 μm (note that the parameter with the smaller number of grains is selected in the experiment), the number of grains of the structure of the circular hole 180 of the wafer pressing ring 18 used in the embodiment is shown in tables 1 and 2, it should be noted that the number of particles in the circular hole structure of the wafer pressing ring not using the embodiment and the number of particles in tables 1 and 2 are the number of particles for detecting the corresponding wafer surface, and the particles with a particle diameter greater than 0.16 μm are selected:

TABLE 1

TABLE 2

The hole diameter parameter of the circular hole 180 is adopted to be unchanged in table 1, the quantity parameter of the circular hole 180 is changed, and the hole diameter parameter of the circular hole 180 is changed while the quantity parameter of the circular hole 180 is adopted to be unchanged in table 2. From the above experimental data results, it can be known that the number of the circular holes 180 is between 16 and 32, the diameter of the circular holes 180 is between 15mm and 30mm, and the number of particles is small.

In summary, the magnetron sputtering apparatus for improving the cleanliness of the magnetron sputtering environment provided by the invention is provided with the upper baffle, the first extension part of the upper baffle is combined with the inclined part to cover the ineffective sputtering area of the target, the accumulation of the stress film layer in the ineffective sputtering area of the target is effectively blocked in the magnetron sputtering process, the stress film layer is formed in the ineffective sputtering area of the target as little as possible, the stress film layer is deposited on the upper baffle, and the upper baffle as a PK piece only needs to be replaced periodically, so that the problem that the stress film layer cracks or even falls off to generate particles due to the gradual accumulation of the stress film layer in the ineffective sputtering area of the target is effectively avoided, and the upper baffle can also block the particles generated in the ineffective sputtering area of the target from entering the sputtering working environment. 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

1. A magnetron sputtering device for improving the cleanliness of a magnetron sputtering environment comprises: permanent magnet device, target backplate, adaptation piece, overhead gage, lower baffle, wafer base and cavity, the target backplate is located the target top, permanent magnet device is located the target backplate top, its characterized in that:

the upper baffle is circumferentially arranged inside the cavity and is used for improving the cleanliness of the magnetron sputtering environment; the upper baffle plate comprises a flanging, an inclined part and a first extending part which are integrally formed from top to bottom, the upper baffle plate is installed on the adapting block through the flanging, the inclined part and the side face of the target material have the same inclination angle, the first extending part extends from the edge of the cavity to the center of the cavity, and the projection of the first extending part in the transverse direction covers the non-effective sputtering area of the edge of the target material, wherein the distance between the projection of the first extending part in the transverse direction and the surface of the target material is 2 mm-3 mm, and the distance between the inclined part and the side face of the target material is 2 mm-3 mm;

the magnetron sputtering apparatus further includes: the wafer clamping ring, the wafer clamping ring evenly is provided with the circular port along circumference, the quantity of circular port is between 16 ~32, the diameter of circular port is between 15mm ~30 mm.

2. The magnetron sputtering device for improving the cleanliness of the magnetron sputtering environment as claimed in claim 1, wherein: the first extension part extends towards the center of the cavity along the transverse direction or extends from the edge of the cavity to the center of the cavity in an inclined manner.

3. The magnetron sputtering device for improving the cleanliness of the magnetron sputtering environment as claimed in claim 1, wherein: the start end of the first extension portion is connected to the end of the inclined portion.

4. The magnetron sputtering device for improving the cleanliness of the magnetron sputtering environment as claimed in claim 1, wherein: the upper baffle plate further comprises a second extending part which extends from the upper part to the lower part of the cavity along the vertical direction; the end of the first extension part is connected with the beginning of the second extension part, or the inclined part is connected with the second extension part, and the first extension part is connected with the inclined part or the second extension part.

5. The magnetron sputtering device for improving the cleanliness of the magnetron sputtering environment as claimed in claim 1, wherein: the projection length of the first extension part in the transverse direction is between 3mm and 10 mm.

6. The magnetron sputtering device for improving the cleanliness of the magnetron sputtering environment as claimed in claim 1, wherein: one side of the upper baffle plate facing the inside of the cavity is a sand blasting surface or a melting and jetting surface.

7. The magnetron sputtering device for improving the cleanliness of the magnetron sputtering environment as claimed in claim 1, wherein: the upper baffle plate is made of stainless steel or titanium.