CN111446146A

CN111446146A - Plasma confinement device and plasma equipment

Info

Publication number: CN111446146A
Application number: CN202010445156.6A
Authority: CN
Inventors: 吴堃
Original assignee: Shanghai Bangxin Semiconductor Equipment Co ltd
Current assignee: Shanghai Bangxin Semiconductor Equipment Co ltd
Priority date: 2020-05-23
Filing date: 2020-05-23
Publication date: 2020-07-24
Also published as: CN111653468A

Abstract

The invention discloses a plasma confinement device which comprises a conductive element and a grounding element which are independent, wherein the conductive element is positioned above the grounding element and is electrically connected with the single end of the grounding element. According to the invention, the single-end electric connection of the conductive element and the grounding element reduces the potential, so that residual charges generated after the plasma collides with the conductive element are more easily conducted away by grounding, and the constraint effect is increased; the conductive element is separated from the grounding element, which increases the stability of the system and the convenience of maintenance.

Description

Plasma confinement device and plasma equipment

Technical Field

The invention relates to the technical field of production equipment in semiconductors and related fields, in particular to a plasma confinement device and plasma equipment.

Background

The plasma processing device utilizes the working principle of a vacuum flexible chamber to process substrates of a nail-feeding semiconductor substrate and a plasma panel. The working principle of the vacuum reaction chamber is that reaction gas containing proper etchant or deposition source gas is introduced into the vacuum reaction chamber, then the vacuum reaction chamber is subjected to jet energy input to activate the reaction gas so as to ignite and maintain plasma, so that a material layer on the surface of a substrate is etched or deposited respectively, and the work is carried out on a semiconductor substrate and a plasma flat plate. For example, capacitive plasma reactors, in which a capacitive discharge is formed between a pair of parallel electrodes when radio frequency power is applied to one or both of the electrodes, have been widely used to process semiconductor substrates and display panels.

The plasma is diffusive, and although a large portion of the plasma may remain in the processing region between a pair of electrodes, a portion of the plasma may fill the entire chamber. For example, the plasma may fill a region around the periphery of the processing region below the vacuum chamber. If the plasma reaches these areas, these areas may be subsequently attacked, deposited, or eroded, which can cause particle contamination inside the chamber, which in turn reduces the reusability of the plasma processing apparatus and may shorten the operating life of the chamber or chamber components. If the plasma is not confined to a certain working area, the charged particles will strike the unprotected area, which in turn leads to impurities and contamination of the surface of the semiconductor substrate.

Accordingly, there is a continuing effort to generate a more stable plasma confined to a processing region. One current idea is to use confinement rings to confine the plasma, but various problems still exist, such as secondary plasma interference, rf magnetic field cross talk, and so on.

Disclosure of Invention

In order to solve the above problems, the present invention provides a plasma confinement device and a plasma apparatus, which can improve secondary plasma interference and shield radio frequency magnetic field crosstalk.

According to a first aspect of the present invention, there is provided a plasma confinement arrangement comprising a conductive element and a ground element which are independent of each other, the conductive element being located above the ground element and being in single-ended electrical connection with the ground element.

Optionally, for the plasma confinement assembly, the form of the electrical connection includes a raised metal surface in direct contact, and the raised position is located at the outer ring or the inner ring.

Optionally, for the plasma confinement assembly, the form of the electrical connection includes a low-resistance conductive interlayer disposed between the conductive element and the ground element, and the electrical conductivity is less than or equal to 5 Ω cm.

Optionally, for the plasma confinement arrangement, the non-electrically connected area of the conductive element and the ground element is greater than 1/2 of the area of the conductive element.

Optionally, for the plasma confinement device, the conductive element implements reduction of plasma density, the ground element implements confinement of an electric field, and the ground loop implements electric field shielding to avoid secondary excitation ionization of plasma.

Optionally, for the plasma confinement arrangement, the conductive element is provided with a plurality of channels, the channels being capable of neutralizing charged particles and passing neutral particles.

Optionally, for the plasma confinement arrangement, the conductive element comprises a plurality of connected concentric rings.

Optionally, for the plasma confinement device, the conductive element is a plate-shaped structure, and the channel is a through hole or a through groove formed in the plate-shaped structure.

According to a second aspect of the present invention there is provided a plasma apparatus comprising a plasma confinement arrangement as described in the first aspect.

The technical scheme of the invention at least has the following beneficial technical effects:

1. the single-end electric connection of the conductive element and the grounding element reduces the potential, so that residual charges generated after the plasma collides with the conductive element are more easily conducted away by grounding, and the constraint effect is increased.

2. The conductive element and the grounding element are separated, so that the stability of the system is improved, the maintenance is convenient, in practical application, the corrosive conductive element of plasma can be frequently replaced or cleaned, and if the two parts are combined into a whole, the grounding loop can be disassembled and changed every time the two parts are maintained, so that the instability of the radio frequency loop is easily generated.

Drawings

FIG. 1 is a schematic cross-sectional view of a plasma confinement arrangement in an embodiment of the invention;

FIG. 2 is a first top view of a plasma confinement device in an embodiment of the invention;

FIG. 3 is a second top view of a plasma confinement arrangement in accordance with an embodiment of the invention;

FIG. 4 is a schematic structural diagram of a plasma apparatus according to an embodiment of the present invention.

Detailed Description

In order to make the technical means, the original characteristics, the achieved purposes and the effects of the invention easily understood, the invention is further described below with reference to the specific embodiments and the attached drawings, but the following embodiments are only the preferred embodiments of the invention, and not all embodiments. Based on the embodiments in the implementation, other embodiments obtained by those skilled in the art without any creative efforts belong to the protection scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.

Specific embodiments of the present invention are described below with reference to the accompanying drawings. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

Referring to fig. 1, an embodiment of the present invention provides a plasma confinement device 100, including a conductive element 101 and a ground element 102, where the conductive element 101 is located above the ground element 102 and is electrically connected to the ground element 101 at a single end 103.

In one embodiment, the form of the electrical connection 103 includes a raised metal surface in direct contact, with the raised location being at either the outer or inner ring.

Or the form of the electric connection comprises a low-resistance conductive interlayer which is arranged between the conductive element and the grounding element, and the conductivity is less than or equal to 5 omega cm.

In one embodiment, the non-electrically connecting area of the conductive element to the ground element is greater than 1/2 of the conductive element area. I.e. contact area of less than 1/2, whether it be contact of raised metal surfaces, or the provision of a conductive interlayer. It is understood that the conductive element area herein refers to the area of the opposite surface of the conductive element to the ground element, and the conductive element and the ground element may be disposed opposite to each other.

In the embodiment of the present invention, the conductive element 101 is used to reduce plasma density, the grounding element 102 is used to realize electric field confinement, and electric field shielding is realized through a grounding loop to avoid secondary excitation ionization of plasma.

In one embodiment of the invention, the conductive element 101 is provided with several channels 1011 capable of neutralizing charged particles and passing neutral particles.

Referring specifically to fig. 2, the conductive element 101 includes a plurality of connected concentric rings. The channels 1011 are formed between adjacent concentric rings. The design of the channel 1011 may follow that a charged particle leaving the processing region must move a distance greater than the mean free path of the particle as it leaves the channel.

The channel 1011 exposes a portion of the ground element 102 as illustrated in fig. 2. According to actual needs, the grounding element 102 may be provided with an opening corresponding to the channel 1011, so that the gas passing through the channel 1011 can smoothly pass through and be transferred to an exhaust device (not shown) of the plasma equipment.

Referring to fig. 3, the conductive element 101 is a plate-shaped structure, and the channel 1011 is a through hole or a through groove formed on the plate-shaped structure. In which figure 3 illustrates a via structure.

The design of the channel 1011 may follow that a charged particle leaving the processing region must move a distance greater than the mean free path of the particle as it leaves the channel.

The channel 1011 exposes a portion of the ground element 102 as illustrated in fig. 3. According to actual needs, the grounding element 102 may be provided with an opening corresponding to the channel 1011, so that the gas passing through the channel 1011 can smoothly pass through and be transferred to an exhaust device (not shown) of the plasma equipment.

The material of the conductive element 101 is selected and can be common materials in the prior art, which are not described in detail herein.

In the present invention, charged particles collide with the conductive element 101 when drawn by the exhaust, specifically the collision may involve the surface of the conductive element 101, and the collision may occur with the side walls when passing partially through the channel 1011, at least once due to the specific design of the channel 1011. Further, since the conductive member 101 is electrically connected to the grounding member 102 in the present invention, the charges in the charged particles can be more easily conducted to the ground after the collision, and thus all the charges become substantially neutral. The conductive element 101 is electrically connected to the ground element 102, so that electric field shielding can be achieved and secondary excitation ionization of plasma can be prevented. The plasma density can be effectively reduced, the number of charged particles in the exhaust gas can be greatly reduced, and the phenomenon of discharge outside the space can be basically eliminated.

In addition, the conductive element 101 and the grounding element 102 are relatively independent, i.e. the separated design, so that the stability of the system and the convenience of maintenance are increased, in practical application, the conductive element 101 can be frequently replaced or cleaned due to the corrosiveness of the plasma, and if the conductive element 101 and the grounding element 102 are integrated, the ground loop can be changed by dismounting each time of maintenance, so that the instability of the radio frequency loop is easily generated. According to the design in the embodiment of the invention, only the conductive element 101 needs to be detached and assembled independently during maintenance, and the grounding loop does not need to be detached and assembled, so that the stability of the system is greatly ensured.

The invention also provides plasma equipment comprising the plasma confinement device. As shown in fig. 4, the plasma confinement device 100 includes an upper electrode 201, a lower electrode 202, and a plasma excitation processing region defined between the upper electrode 201 and the lower electrode 202, wherein the lower electrode 202 is surrounded by the upper electrode 201.

Compared with the prior art, the technical scheme of the invention at least has the following beneficial technical effects:

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and the preferred embodiments of the present invention are described in the above embodiments and the description, and are not intended to limit the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A plasma confinement arrangement comprising a separate conductive element and a ground element, the conductive element being positioned above the ground element and being in single-ended electrical connection with the ground element.

2. A plasma confinement arrangement according to claim 1, wherein the electrical connection is in the form of a raised metal surface in direct contact, the raised location being located at the outer or inner ring.

3. A plasma confinement arrangement according to claim 1, wherein the electrical connection is in the form of a low resistance conductive sandwich disposed between the conductive element and the grounded element, and has a conductivity of 5 Ω cm or less.

4. A plasma confinement arrangement according to claim 2 or claim 3, wherein the electrically non-connecting area of the conductive element to the ground element is greater than 1/2 of the area of the conductive element.

5. A plasma confinement arrangement according to claim 1, wherein the conductive element effects a reduction in plasma density, the ground element effects confinement of an electric field, and the electric field is shielded by a ground return path to avoid reignition ionization of the plasma.

6. A plasma confinement arrangement according to claim 1 or 5, wherein the conductive element is provided with a plurality of passages capable of neutralising charged particles and passing neutral particles.

7. A plasma confinement arrangement according to claim 6, wherein the conductive element comprises a plurality of connected concentric rings.

8. A plasma confinement arrangement according to claim 6, wherein the conductive element is a plate-like structure and the passage is a through hole or a through slot provided in the plate-like structure.

9. A plasma apparatus comprising a plasma confinement arrangement according to any one of claims 1 to 8.