Gas uniformizing device of plasma cavity in atomic layer deposition equipment

Abstract

The utility model belongs to the technical field of remote plasmas, and particularly relates to a gas uniformizing device of a plasma cavity in atomic layer deposition equipment. The gas uniformizing device adopts a double-layer gas uniformizing disc structure and comprises an upper-layer gas uniformizing disc and a lower-layer gas uniformizing disc, the upper-layer gas uniformizing disc is mounted at a barrel opening of the plasma inner cavity and is connected with other parts of the outer cavity through screw holes in the outer side edge of the upper layer; the lower-layer gas uniformizing disc is mounted at a position 5mm below the upper-layer gas uniformizing disc and is connected with the upper-layer gas uniformizing disc through screw holes in the outer edge An annular hole and tiny ventilation holes are designed in the lower-layer gas uniformizing disc, and the annular hole is used for sampling airflow in a sample space and reducing the flow speed; the upper disc introduces airflow into the gas collecting space through the middle hole, finally the airflow is reduced in flow velocity and diffused to the lower disc through the inclined hole in the farthest way, and the minimum center distance of the upper disc and the lower disc is set to be of a champagne tower structure, so that the airflow is diffused as far as possible, the flow velocity is reduced, the deposition uniformity is improved, and finally the sample treatment uniformity is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of remote plasma, and particularly relates to a gas homogenizing device. Background Art

[0002] Low-temperature plasma technology is an important material processing technology, which has the advantages of energy saving, high efficiency, and high material applicability. Generally, low-temperature plasma technology is mainly classified into direct plasma, remote plasma, radical-enhanced ALD, etc. from the perspective of equipment structure. Among them, remote plasma technology is based on the different survival lifetimes of various active particles (electrons, ions, free radicals) in the plasma gas; different from the conventional plasma processing area, the position of the material to be processed is in the remote area (a certain distance from the plasma source), where the electron and ion number densities rapidly decay, while the concentration of long-lived metastable particles and active free radicals is relatively high, which can reduce the probability of irreversible damage to the material surface caused by high-energy particles and has a good material surface treatment effect.

[0003] For PECVD and PEALD technologies, the uniformity of plasma treatment is an important indicator. When the plasma gas reaches the surface of the sample stage, it is affected by the positions of the air inlet, the expansion component, the sample stage, and the air outlet, resulting in relatively uneven reaction results on the sample surface and partial material damage caused by the impact of high-energy particles. With the improvement of material precision, it is urgent to improve the uniformity of plasma treatment. Summary of the Invention

[0004] The purpose of the utility model is to provide a gas homogenizing device for a plasma cavity in an atomic layer deposition device, namely a double-layer gas homogenizing disk, to solve the problem of poor uniformity of the plasma-treated material surface.

[0005] The gas homogenizing device for a plasma cavity in the atomic layer deposition device provided by the utility model adopts a double-layer gas homogenizing disk structure, that is, it includes an upper gas homogenizing disk (referred to as the upper disk for short) and a lower gas homogenizing disk (referred to as the lower disk for short); its structure is shown in Figures 1 - 5 as follows. The upper gas homogenizing disk is installed at the barrel opening of the plasma inner cavity and is connected to other parts of the outer cavity through the screw holes on the outer edge of the upper layer; the lower gas homogenizing disk is installed 5 mm below the upper gas homogenizing disk and is similarly connected through the screw holes on the outer edge of the lower layer; where:

[0006] The upper gas distribution plate contains a middle cavity for concentrating the air flow, which is then diffused into the space through the holes in the upper cavity. Specifically, the upper plate is designed as a double-layer structure. There is a gas collection space between its upper and lower layers. The upper layer is a circular flat plate with holes in the center part, and the lower layer is a circular plate. The lower circular plate protrudes upward into the space at a certain inclination angle towards the center, forming a conical shape. There are multiple circles (such as 5 - 10) of holes evenly distributed on the lower circular plate at a certain interval. The outermost circle of the upper plate is a connecting part for mating and connecting with the mouth of the plasma inner cavity barrel. There are screw holes at the outer edge of the upper plate for connecting with the plasma inner cavity.

[0007] The lower plate is a circular plate with the same size as the upper plate. There are two circles of evenly arranged annular holes on its outer side, and multiple circles (such as 4 - 8 circles) of inner circle holes are opened in the annular holes. There are screw holes at the outer edge of the lower plate for mating and connecting with the plasma equipment housing. The center of the gas distribution plate is coaxial with the sample stage. Therefore, the inner annular holes of the lower plate are located at a distance from the center greater than or equal to the distance from the edge of the sample stage. Its function is to divert the strong air flow to the lower part of the sample stage and reduce the air pressure and flow rate at the reaction center.

[0008] Preferably, the holes on the upper plate and the holes on the lower plate are each circularly distributed in each circle. The closest point to the center and the farthest point from the center of each circle of holes (at the air inlet, it is the air inlet itself) do not coincide and there is a certain distance, so that when the plasma gas flows downward, it has a tendency to flow outward, travels as far as possible, and reduces the flow rate, making the air flow distribution in the shape of a "champagne tower".

[0009] Preferably, the outermost layer of the lower plate has two annular holes with a width of 2.5 mm.

[0010] Preferably, the diameter of the inner circle holes on the inner side of the lower plate is 2.5 mm.

[0011] Preferably, the distance from the center of the outermost annular hole on the lower plate is greater than the position of the edge of the lower sample stage.

[0012] Preferably, the diameter of the holes on the upper plate is larger than that of the holes on the lower plate. For example, the hole diameter is 5 mm.

[0013] Preferably, the holes on the upper plate have a certain inclination angle, and the inclination angle of the holes becomes smaller as the distance from the center increases. The inclination angle refers to the angle between the central axis of the hole and the vertical direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic three-dimensional structure diagram of the lower plate in the present utility model.

[0015] Figure 2 It is a top view of the lower plate in the present utility model.

[0016] Figure 3 It is a front view of the lower plate in the present utility model.

[0017] Figure 4 This is a schematic diagram of the three-dimensional structure of the upper plate in the present utility model.

[0018] Figure 5 This is a front sectional view of the upper plate in the present utility model.

[0019] Reference numerals in the figure: 1 is the screw hole of the lower plate, 2 is the annular hole, 3 is the connecting bar, 4 is the inner ring hole; 5 is the central hole, 6 is the screw hole on the outer side of the upper plate, 7 is the connecting part, 8 is the gas collection space, 9 is the inclined hole, (9a, 9b,... 9i respectively correspond to the first inclined hole, the second inclined hole... the ninth inclined hole). Specific embodiments

[0020] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0021] It should be noted that when an element is referred to as being combined with another element, it can be directly on the other element or there may be multiple other elements present at the same time. When an element is referred to as being connected, it can be directly connected to the other element.

[0022] In addition, it should also be noted that the orientation terms such as upper, lower, inner, outer, and center in the embodiments of the present utility model are only relative to each other or are referenced based on the normal use state of the product, and should not be considered restrictive. The following describes the implementation of the present utility model in detail in conjunction with specific embodiments.

[0023] Figure 1 This is a schematic diagram of the three-dimensional structure of the lower plate. Figure 2 This is a top view of the lower plate. As Figure 1 、 Figure 2As shown in the figure, the lower plate is disk-shaped with a thickness of 5 mm. The outermost circle of the disk is the lower plate screw hole 1 with a radius of 2.25 mm. The holes are far from the center and are used to combine with the plasma equipment shell, not for ventilation in the cavity. The widths of the two outer annular holes 2 on the outer side of the lower plate are both 2.5 mm. Since the center of the gas distribution plate is coaxial with the sample stage, the innermost annular hole 2 is the smallest, and its distance from the center is greater than or equal to the maximum distance of the sample stage. Its function is to divert the strong airflow under the sample stage and reduce the air pressure and flow rate at the reaction center. The connecting bars 3 between the two annular holes are used to connect each layer of the lower plate. There are multiple inner holes 4 arranged evenly inside the two annular holes. There are 6 circles of inner holes 4 in total. The distance of each circle from the center shows an arithmetic progression distribution, and the ratio of the number of holes in each layer to the distance from the center is roughly the same, so that the hole density of each circle is roughly the same. The diameter of the restricted hole is 2.5 mm, which is smaller than the diameter of the holes in the upper plate. And the distance between the outermost hole in the inner holes 4 and the nearest outer annular hole 2 is less than the distance between each circle of inner holes. It must be noted that in addition to what is shown in the present utility model technology, the distribution of the inner holes 4 can not only be a uniform distribution, that is, the distance between each circle is the same, but also can choose to use two different distributions of "gradually decreasing the distance to the outer circle" or "gradually increasing the distance to the outer circle".

[0024] Figure 3 The front view of the lower plate provided for the implementation of the present utility model. Figure 4 The three-dimensional structure schematic diagram of the upper plate provided for the implementation of the present utility model. Figure 5 The front sectional view of the upper plate provided for the implementation of the present utility model. The basic structure of the upper plate is basically the same as that of the lower plate, showing a disk distribution. The thickness of the upper layer is 5 mm (excluding the gas collection space 8). There are upper plate outer side screw holes 6 at the connection part 7 between the outermost circle of the upper plate and the outer cavity. The upper plate contains a larger central hole 5 with a radius of 5 mm, which is used to introduce the reaction airflow into the lower gas collection space 8. The maximum radius of the outer wall of the gas collection space 8 is closely attached to the barrel wall of the plasma inner cavity, ensuring that the gas can only flow downward after flowing out of the hole. The inner cavity of the gas collection space 8 is a conical structure, which can disperse the high-flow gas flowing into from the central hole 5, reduce the flow rate, and expand the airflow space. The radius of the holes in the upper plate is 2.5 mm larger than that in the lower plate. There are multiple circles of inclined holes 9 arranged evenly on the bottom plate of the gas collection space 8 below the upper plate. The number of circles of the inclined holes 9 is 9. Starting from the innermost inclined hole to the outside, they are recorded as the first inclined hole 9a, the second inclined hole 9b, ‥‥‥, the ninth inclined hole 9i in turn; among them, the inclination angle of the first inclined hole 9a is 90° (the inclination angle refers to the angle between the axis of the hole and the vertical direction), the inclination angle of the second inclined hole 9b is 80°, the inclination angle of the third inclined hole 9c is 70°, the inclination angle of the fourth inclined hole 9d is 60°, the inclination angle of the fifth inclined hole 9e is 50°, the inclination angle of the sixth inclined hole 9f is 40°, the inclination angle of the seventh inclined hole 9g is 30°, and the inclination angles of the eighth inclined hole 9h and the ninth inclined hole 9i are both 20° outside the cone in the inner cavity of the gas collection space 8.

[0025] In addition, after the upper plate and the lower plate are installed in the basic order, the outermost ring of holes (the one with the shortest distance from the center among each ring of holes) is always farther than the previous ring, which ensures that the air flow flowing down from the upper cavity cannot directly reach the surface of the sample stage through the holes, enabling the air flow to diffuse along a relatively long distance as much as possible, achieving the structural function of reducing the flow rate.

[0026] The above-described embodiments are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications, substitutions, and improvements, etc. These modifications, substitutions, and improvements should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A gas homogenizing device for a plasma chamber in an atomic layer deposition equipment, characterized in that, Adopt a double-layer air distribution plate structure, that is, it includes an upper-layer air distribution plate, abbreviated as the upper plate, and a lower-layer air distribution plate, abbreviated as the lower plate; among them, the upper-layer air distribution plate is installed at the barrel opening of the plasma inner cavity and is connected to other parts of the outer cavity through the screw holes on the outer edge of the upper layer; the lower-layer air distribution plate is installed 5 mm below the upper-layer air distribution plate. Similarly, it is connected through the screw holes on the outer edge of the lower layer; among them: The upper-layer air distribution plate contains a middle cavity for concentrating air flow and then diffusing it into the space through the holes in the upper cavity; specifically, the upper plate is designed as a double-layer structure; the space between its upper and lower layers is a gas collection space, the upper layer is a circular flat plate with a central hole in the center, and the lower layer is a circular plate. The lower circular plate protrudes upward into the space at a certain inclination angle towards the center, forming a cone shape; multiple circles of inclined holes are evenly distributed on the lower circular plate at a certain interval; the outermost circle of the upper plate is a connecting part for fitting and connecting with the barrel opening of the plasma inner cavity; the outer edge of the upper plate is provided with outer-side screw holes of the upper plate for connecting with the plasma inner cavity; The lower plate is a circular plate with the same size as the upper plate. There are two circles of the same wide annular holes on its outer side, and multiple inner-circle holes are opened inside the annular holes; there are lower-plate screw holes on the outer edge of the lower plate for fitting and connecting with the plasma equipment shell; the center of the air distribution plate is coaxial with the sample stage. Therefore, the inner annular holes of the lower plate are at a distance from the center position greater than or equal to the maximum distance of the sample stage. Its function is to divert the strong air flow to the lower part of the sample stage and reduce the reaction center air pressure and flow rate.

2. The air distribution device according to claim 1, wherein, The holes on the upper plate and the holes on the lower plate are all circularly distributed in each circle. The closest distance to the center and the farthest distance to the center of each circle of holes do not coincide and there is a certain distance, so that when the plasma gas flows downward, it has a tendency to flow outward and travels as far as possible to reduce the flow rate.

3. The air distribution device according to claim 2, characterized in that, The width of the two annular holes in the outermost layer of the lower plate is 2.5 mm; the diameter of the inner-circle holes inside the lower plate is 2.5 mm; the distance of the outermost annular hole of the lower plate from the center position is greater than the edge position of the lower sample stage.

4. The air distribution device according to claim 3, wherein, The number of circles of the inner-circle holes inside the lower plate is 6. The distance from the center of each circle shows an arithmetic progression distribution, and the ratio of the number of holes in each layer to the distance from the center is the same, so that the hole density of each circle remains the same.

5. The air distribution device according to claim 4, characterized in that, The number of circles of the multiple circles of inclined holes on the upper plate is 9. Starting from the innermost circle of inclined holes and outward, they are successively recorded as the first inclined hole, the second inclined hole, ‥‥‥, the ninth inclined hole; among them, the inclination angle of the first inclined hole is 90°, the inclination angle of the second inclined hole is 80°, the inclination angle of the third inclined hole is 70°, the inclination angle of the fourth inclined hole is 60°, the inclination angle of the fifth inclined hole is 50°, the inclination angle of the sixth inclined hole is 40°, the inclination angle of the seventh inclined hole is 30°, and the eighth and ninth inclined holes are both outside the cone in the middle cavity of the gas collection space, with an inclination angle of 20°. Here, the inclination angle refers to the angle between the axis of the inclined hole and the vertical direction.

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