CN115295389A

CN115295389A - Inductively coupled plasma device and semiconductor thin film device

Info

Publication number: CN115295389A
Application number: CN202211014291.0A
Authority: CN
Inventors: 余先炜; 田才忠; 王美玲; 林保璋
Original assignee: Shengjisheng Semiconductor Technology Beijing Co ltd
Current assignee: Shengjisheng Semiconductor Technology Beijing Co ltd
Priority date: 2022-08-23
Filing date: 2022-08-23
Publication date: 2022-11-04

Abstract

The invention discloses an inductively coupled plasma device and semiconductor thin film equipment, the inductively coupled plasma device includes: the plasma device comprises a plasma device body, an isolation cover plate, an antenna and a shielding piece; the isolation cover plate is covered on the plasma device body to form a vacuum chamber, the antenna is arranged above the isolation cover plate, and the shielding piece is arranged on the isolation cover plate and is positioned between the isolation cover plate and the antenna; the antenna comprises a plurality of sub-antennas arranged side by side, and the sub-antennas are connected in parallel; the shielding part comprises a first component and a plurality of second components, wherein the first component and the plurality of second components are of straight strip structures, and the plurality of second components are arranged at intervals along the length direction of the first component and perpendicularly intersect with the first component. According to the invention, the plurality of sub-antennas are arranged side by side, and the shielding piece is arranged between the sub-antennas and the isolation cover plate, so that the problem of poor plasma uniformity in the cavity of the inductively coupled plasma device is solved.

Description

Inductively coupled plasma device and semiconductor thin film device

Technical Field

The invention relates to the technical field of semiconductor manufacturing, in particular to an inductively coupled plasma device and semiconductor thin film equipment.

Background

Inductively Coupled Plasma (ICP) chambers are common devices in Plasma processes of microelectronic fabrication. In such an apparatus, the rf magnetic field in the low pressure reaction chamber is induced by transmitting rf energy generated by rf oscillating current through the planar antenna into the chamber through the dielectric window. The magnetic field produces a circulating stream of electrons in the process gas introduced into the chamber, creating a plasma of ions, free electrons, neutral species and radicals. The energy coupling efficiency, i.e., the amount of energy transferred to the plasma through the antenna, is an important factor in ICP devices. ICP source devices typically have two modes of coupling: a capacitive coupling mode (E-mode) and an inductive mode (H-mode). Where the coupling efficiency of the capacitively coupled mode is low, it is desirable to try to reduce it in ICP devices. In the initial stage of generating plasma by discharging of the ICP device, low-density plasma is generated in an E mode, when the plasma density reaches a certain value, E-H mode conversion occurs, and plasma with higher density is generated mainly by discharging in an H mode.

In the process of generating plasma by the ICP device, different load impedances exist in an E mode and an H mode of the plasma, and a matching network needs to be adjusted in time to ensure that an RF power supply and a load realize impedance matching. When the two modes are switched in the plasma generation process, the instability of the plasma can be caused, and the impedance of the plasma can be changed. The rapid change in the impedance of the plasma affects the energy coupling efficiency of the antenna, which in turn changes the impedance of the plasma. This results in low amplitude impedance oscillations, which can result in the matching network failing to reach a stable matching state, and the plasma also being difficult to reach a stable state.

Disclosure of Invention

The present invention provides an inductively coupled plasma device and a semiconductor thin film device, so as to solve the problem of poor plasma uniformity in a chamber of the inductively coupled plasma device.

In order to solve the above technical problems, according to an aspect of the present invention, there is provided an inductively coupled plasma apparatus including: the plasma device comprises a plasma device body, an isolation cover plate, an antenna and a shielding piece;

the isolation cover plate is covered on the plasma device body to form a vacuum chamber, the antenna is arranged above the isolation cover plate, and the shielding piece is arranged on the isolation cover plate and is positioned between the isolation cover plate and the antenna;

the antenna comprises a plurality of sub-antennas arranged side by side, and the sub-antennas are connected in parallel;

the shielding part comprises a first component and a plurality of second components, wherein the first component and the plurality of second components are of straight strip structures, and the plurality of second components are arranged at intervals along the length direction of the first component and are perpendicularly intersected with the first component.

In some embodiments, the plurality of sub-antennas are of a planar single-helix structure, each two sub-antennas are divided into a group, and the winding directions of the two sub-antennas in each group are opposite.

In some embodiments, the sub-antenna is wound from a hollow metal tube.

In some embodiments, a cooling substance is disposed within the metal tube to cool the sub-antenna.

In some embodiments, the straight strip-shaped structure with the largest length in the first member and the second members is parallel to the arrangement direction of the sub-antennas.

In some embodiments, a plurality of the second members are symmetrically arranged with the first member and/or the second member at the center of the first member as a center line.

In some embodiments, the length of the plurality of second members decreases in sequence in a direction from the center of the first member toward both ends.

In some embodiments, the plurality of second members sequentially increase in length in a direction from the center of the first member toward both ends.

In some embodiments, a heating element and/or a grounding element is disposed on the shield.

According to another aspect of the present invention, there is provided a semiconductor thin film device comprising the inductively coupled plasma apparatus according to any one of the above embodiments.

Compared with the prior art, the invention has obvious advantages and beneficial effects. By the technical scheme, the inductively coupled plasma device and the semiconductor thin film equipment can achieve considerable technical progress and practicability, have industrial wide utilization value and at least have the following advantages:

(1) The antenna of the inductively coupled plasma device is provided with the plurality of sub-antennas which are arranged side by side, so that large-range uniform plasma can be formed in the vacuum chamber of the inductively coupled plasma device to meet the use requirement of a large-size substrate.

(2) According to the invention, the shielding piece is arranged between the isolation cover plate and the antenna, so that the uniformity of the radial distribution of the plasma can be effectively adjusted, and the area with uniform radial distribution is enlarged.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of an inductively coupled plasma apparatus according to an embodiment of the present invention;

fig. 2 shows a schematic structural diagram of an antenna according to an embodiment of the present invention;

FIG. 3 shows a schematic structural view of a shield according to an embodiment of the invention;

fig. 4 shows a schematic structural view of a shield according to another embodiment of the present invention.

[ description of symbols ]

1: radio frequency power supply

2: impedance matching network

3: antenna with a shield

31: sub-antenna

4: plasma device body

5: isolation cover plate

6: vacuum chamber

7: wafer

8: carrying platform

9: injection hole

10: air pump interface

11: shielding element

111: first member

112: second member

Detailed Description

In order to further illustrate the present invention, the following detailed description of an inductively coupled plasma device and a semiconductor thin film apparatus according to the present invention is provided with reference to the accompanying drawings.

As shown in fig. 1, the inductively coupled plasma device includes a radio frequency power supply 1, an impedance matching network 2 (impedance matching network), an antenna 3 (antenna), a plasma device body 4, and an isolation cover plate 5. The radio frequency power supply 1, the impedance matching network 2 and the antenna 3 are sequentially connected, an electromagnetic field is generated in a vacuum chamber 6 surrounded by the plasma device body 4 and the isolation cover plate 5, and then the gas in the vacuum chamber 6 generates plasma through electromagnetic induction.

The antenna 3 in the inductively coupled plasma device is arranged close to the isolation cover plate 5 of the vacuum chamber 6 and is connected with the radio frequency power supply 1 and the impedance matching network 2, and the radio frequency power supply 1 maximizes the power transmitted to the antenna 3 by adjusting the impedance matching network 2. The radio frequency current (RF current) loaded into the antenna 3 generates a radio frequency electromagnetic field around the antenna 3 and penetrates through the isolation cover plate 5 (dielectric) to reach the vacuum chamber 6, and the gas in the vacuum chamber 6 is ionized in the radio frequency electromagnetic field to form plasma, so that the wafer 7 (placed on the carrier 8) is processed by the plasma. The process gas is injected into the vacuum chamber 6 through the injection hole 9 and is discharged out of the vacuum chamber 6 through the chamber air pump port 10, thereby forming a negative pressure in the vacuum chamber 6.

An embodiment of the present invention provides an inductively coupled plasma device, as shown in fig. 1, including a plasma device body 4, an isolation cover plate 5, an antenna 3, and a shielding member 11.

The isolation cover plate 5 is covered on the plasma device body 4 and surrounds to form a vacuum chamber 6. The antenna 3 is disposed above the isolation cover 5 to generate a radio frequency electromagnetic field within the vacuum chamber 6. The shield 11 is disposed on the isolation cover 5 and between the isolation cover 5 and the antenna 3.

Specifically, the shielding member 11 is a faraday shield, and the shielding member 11 controls the radio frequency electromagnetic field generated by the antenna 3 to control the magnetic field intensity in different areas in the vacuum chamber 6, so as to adjust the magnetic field uniformity in the radial direction of the vacuum chamber 6.

In one embodiment, as shown in fig. 2, the antenna 3 includes a plurality of sub-antennas 31 arranged side by side, and the plurality of sub-antennas 31 are connected in parallel to the impedance matching network 2 of the inductively coupled plasma device.

According to the invention, the antenna 3 is formed by arranging the sub-antennas 31 side by side, and the large-range uniform plasma can be formed in the vacuum chamber 6 of the inductively coupled plasma device, so that the use requirement of a large-size substrate can be met. By arranging a plurality of sub-antennas 31 in parallel, the inductance generated by the antenna 3 can be reduced, and the energy coupling efficiency can be improved in the process of generating plasma.

Specifically, as shown in fig. 2, the plurality of sub-antennas 31 are in a planar single-spiral structure, each two sub-antennas 31 are divided into a group, and the winding directions of the two sub-antennas 31 in each group are opposite. That is, in the two sub-antennas 31 in each group, the winding direction of one sub-antenna 31 is clockwise, and the winding direction of the other sub-antenna 31 is counterclockwise.

Preferably, the antenna 3 comprises four sub-antennas 31, the four antennas 3 are divided into two groups, each group comprising two sub-antennas 31. Of course, the antenna 3 may also include six, eight, etc. sub-antennas 31, and the invention is not limited to the number of the sub-antennas 31.

The antenna 3 can be formed by winding a solid metal wire or a hollow metal tube.

Further, when the antenna 3 is formed by winding a hollow metal tube, a cooling material may be introduced into the metal tube to cool the antenna 3. The cooling material may be a liquid or a gas with low conductivity, but the invention is not limited thereto.

As shown in fig. 3 and 4, the shielding member 11 includes a first member 111 having a straight bar structure and a plurality of second members 112 having a straight bar structure, and the plurality of second members 112 are spaced apart along a length direction of the first member 111 and perpendicularly intersect the first member 111.

In this embodiment, the plurality of second members 112 may be uniformly spaced, that is, the distance between each adjacent two second members 112 is the same. Of course, the plurality of second members 112 may also be provided in a non-uniformly spaced pattern. For example, taking the second member 112 located at the center line of the first member 111 as the boundary line, the distances between the remaining second members 112 located at both sides of the second member 112 are the same, but the distance between the second member 112 located at the center line of the first member 111 and the adjacent second member 112 is different from the distances between the other adjacent second members 112.

Of course, whether the plurality of second members 112 are uniformly spaced may be adjusted according to the pattern and arrangement of the antenna 3, and the present invention is not limited to whether the plurality of second members 112 are uniformly spaced.

In one embodiment, the straight stripe structure with the largest length in the first member 111 and the plurality of second members 112 is parallel to the arrangement direction of the plurality of sub-antennas 31.

Specifically, when the straight strip-shaped structure with the largest length in the first member 111 and the plurality of second members 112 is the first member 111, then the first member 111 is parallel to the arrangement direction of the plurality of sub-antennas 31; when the straight bar-shaped structure with the largest length in the first member 111 and the plurality of second members 112 is one of the second members 112, then the second member 112 with the largest length is parallel to the arrangement direction of the plurality of sub-antennas 31.

In one embodiment, the second members 112 are symmetrically disposed with respect to the first member 111, that is, each of the second members 112 has the same length on both sides of the first member 111.

In another embodiment, the plurality of second members 112 are symmetrically disposed with the second member 112 at the center of the first member 111 as a center line. That is, when the distance from each of the second members 112 located at the center of the first member 111 is the same among the plurality of second members 112, the lengths of the two members are the same.

In another embodiment, as shown in fig. 3 and 4, the plurality of second members 112 are symmetrically disposed with respect to the first member 111 as a center line, and also symmetrically disposed with respect to the second member 112 at the center of the first member 111 as a center line. That is, not only are the lengths of each of the second members 112 on both sides of the first member 111 the same, but also the lengths of two of the plurality of second members 112 are the same when the distance from each of the two second members 112 at the center of the first member 111 is the same.

Further, the lengths of the plurality of second members 112 are different, and specifically, the lengths of the second members 112 sequentially change in a direction from the center of the first member 111 toward both ends of the first member 111.

In one embodiment, as shown in fig. 3, the length of the second member 112 decreases in order from the center of the first member 111 toward both ends of the first member 111. That is, of the plurality of second members 112, the length of the second member 112 located at the center of the first member 111 is the largest, and the lengths of the second members 112 are sequentially decreased toward both ends of the first member 111.

In another embodiment, as shown in fig. 4, the length of the second member 112 increases in order from the center of the first member 111 toward both ends of the first member 111. That is, of the plurality of second members 112, the length of the second member 112 at the center of the first member 111 is smallest, and the lengths of the second members 112 sequentially increase toward both ends of the first member 111.

In an embodiment, a heating element (not shown) is arranged on the shield 11 to heat the shield 11.

In an embodiment, the shielding member 11 is provided with a grounding element, so as to ground the shielding member 11 through the grounding element, so as to reduce the parasitic capacitance of the shielding member 11, reduce the capacitive coupling portion for generating plasma, reduce the amplitude of impedance oscillation, and further improve the stability of plasma.

The embodiment of the invention also provides semiconductor thin film equipment which comprises the inductively coupled plasma device in any one of the embodiments.

Although the present invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present invention.

Claims

1. An inductively coupled plasma apparatus, comprising: the plasma device comprises a plasma device body, an isolation cover plate, an antenna and a shielding piece;

the shielding piece comprises a first component and a plurality of second components, wherein the first component and the plurality of second components are of straight strip structures, and the plurality of second components are arranged at intervals along the length direction of the first component and perpendicularly intersect with the first component.

2. The inductively coupled plasma device of claim 1, wherein the plurality of sub-antennas are planar single helical structures, each two sub-antennas are grouped into a group, and the winding directions of the two sub-antennas in each group are opposite.

3. The inductively coupled plasma device of claim 1 or 2, wherein the sub-antenna is formed by winding a hollow metal tube.

4. The inductively coupled plasma device of claim 3, wherein a cooling substance is disposed within the metal tube to cool the sub-antenna.

5. The inductively coupled plasma device of claim 1, wherein the straight strip-like structure with the largest length in the first member and the plurality of second members is parallel to the arrangement direction of the plurality of sub-antennas.

6. The inductively coupled plasma device of claim 5, wherein the plurality of second members are symmetrically arranged with the first member and/or the second member at the center of the first member as a center line.

7. The inductively coupled plasma device of claim 6, wherein the lengths of the plurality of second members decrease sequentially in a direction from the center of the first member toward both ends.

8. The inductively coupled plasma device of claim 6, wherein the lengths of the plurality of second members increase sequentially in a direction from the center of the first member toward both ends.

9. An inductively coupled plasma device according to any of claims 5-8, wherein the shield is provided with heating elements and/or grounding elements.

10. A semiconductor thin film device comprising the inductively coupled plasma apparatus as claimed in any one of claims 1 to 9.