阅读说明：本技术 沉积设备 (Deposition apparatus ) 是由 陈兆滨 于 2020-04-23 设计创作，主要内容包括：本发明公开一种沉积设备,包括：反应腔室以及位于反应腔室内且与反应腔室同轴设置的上电极(6)、支撑环(5)、隔离环(15)和聚焦环(102),隔离环(15)和聚焦环(102)设置于上电极(6)的外周壁与支撑环(5)的内周壁之间；隔离环(15)的内部设有空腔,空腔用于容纳液态介质材料；支撑环(5)内设有与空腔连通的进液通道(16)和排液通道(17),进液通道(16)用于向空腔内输送液态介质材料,排液通道(17)用于将空腔中的液态介质材料排出。本公开实施例中,通过对隔离环内部的空腔更换具有不同介电常数的液态介质,能够改变隔离环的隔离电容,从而实现对等离子体的气体解离度和电子温度进行控制。(The invention discloses a deposition apparatus, comprising: the device comprises a reaction chamber, an upper electrode (6), a support ring (5), an isolation ring (15) and a focusing ring (102), wherein the upper electrode (6), the support ring (5), the isolation ring (15) and the focusing ring (102) are positioned in the reaction chamber and are coaxially arranged with the reaction chamber, and the isolation ring (15) and the focusing ring (102) are arranged between the outer peripheral wall of the upper electrode (6) and the inner peripheral wall of the support ring (5); a cavity is arranged in the isolating ring (15) and is used for containing liquid medium materials; a liquid inlet channel (16) and a liquid discharge channel (17) which are communicated with the cavity are arranged in the support ring (5), the liquid inlet channel (16) is used for conveying liquid medium materials into the cavity, and the liquid discharge channel (17) is used for discharging the liquid medium materials in the cavity. In the embodiment of the disclosure, the liquid medium with different dielectric constants is replaced in the cavity inside the isolating ring, so that the isolating capacitance of the isolating ring can be changed, and the gas dissociation degree and the electron temperature of the plasma can be controlled.)

1. A deposition apparatus comprising: the device comprises a reaction chamber, an upper electrode (6), a support ring (5), a separating ring (15) and a focusing ring (102), wherein the upper electrode, the support ring (5), the separating ring (15) and the focusing ring (102) are positioned in the reaction chamber and are coaxially arranged with the reaction chamber, and the separating ring (15) and the focusing ring (102) are arranged between the outer peripheral wall of the upper electrode (6) and the inner peripheral wall of the support ring (5); the isolating ring is characterized in that a cavity is arranged inside the isolating ring (15), and the cavity is used for containing a liquid medium material; be equipped with in support ring (5) with inlet channel (16) and drainage channel (17) of cavity intercommunication, inlet channel (16) be used for to carry in the cavity liquid medium material, drainage channel (17) are used for with in the cavity liquid medium material discharges.

2. The deposition apparatus according to claim 1, wherein the spacer ring comprises a first upper annular portion (20) and a first lower annular portion (21), the first upper annular portion (20) extending radially outward along a top of the first lower annular portion (21);

the cavity comprises a first annular cavity (24) arranged in the first upper annular part (20) and a second annular cavity (25) arranged in the first lower annular part (21), and the second annular cavity (25) is communicated with the first annular cavity (24).

3. The deposition apparatus according to claim 1, wherein the spacer ring comprises a second upper annular portion (22) and a second lower annular portion (23), the second upper annular portion (22) extending radially outward of the second lower annular portion (23) from a top of the second lower annular portion (23);

the cavity comprises a third annular cavity (26) provided in the second upper annular portion (22).

4. The deposition apparatus according to claim 2, wherein the spacer ring further comprises an annular solid portion (19), the annular solid portion (19) is located at an outer periphery of the first upper annular portion (20), and an upper end surface of the annular solid portion (19) is lower than an upper end surface of the first upper annular portion (20).

5. The deposition apparatus according to claim 3, wherein the spacer ring further comprises an annular solid portion (19), the annular solid portion (19) is located at an outer periphery of the second upper annular portion (22), and an upper end face of the annular solid portion (19) is lower than an upper end face of the second upper annular portion (22).

6. A deposition apparatus according to claim 4 or 5, characterized in that the upper electrode (6) comprises an upper end and a lower end, the edge of the upper end having a downward projection, the lower end face of the projection being in contact with the upper end face of the annular solid portion (19).

7. The deposition apparatus according to claim 3, wherein the bottom of the second upper annular portion (22) is provided with a liquid inlet and a liquid outlet which are communicated with the third annular cavity (26), one end of the liquid inlet channel (16) is connected with the liquid inlet, the other end of the liquid inlet channel (16) is provided with a liquid inlet valve (13) and extends to the outside of the reaction chamber; one end of the liquid discharge channel (17) is connected with the liquid discharge port, and the other end of the liquid discharge channel (17) is provided with a liquid outlet valve (14) and extends to the outside of the reaction chamber.

8. The deposition apparatus according to claim 2, wherein the bottom of the first upper annular portion (20) is provided with a liquid inlet and a liquid outlet which are communicated with the first annular cavity (24), one end of the liquid inlet channel (16) is connected with the liquid inlet, the other end of the liquid inlet channel (16) is provided with a liquid inlet valve (13) and extends to the outside of the reaction chamber; one end of the liquid discharge channel (17) is connected with the liquid discharge port, a liquid discharge pipe (27) is arranged in the liquid discharge channel (17), one end of the liquid discharge pipe (27) extends to the bottom end of the second annular cavity (25) through the liquid discharge port, the other end of the liquid discharge channel (17) extends to the outside of the reaction chamber, and the other end of the liquid discharge pipe (27) extends to the outside of the reaction chamber and is provided with a liquid discharge pump.

9. The deposition apparatus according to claim 8, wherein the drain pipe (27) is made of an insulating material.

10. The deposition apparatus according to claim 4, wherein the length of the first upper annular portion (20) is 20mm to 40mm, the thickness of the first upper annular portion (20) is 13mm to 18mm, the thickness of the annular solid portion (19) is 5mm to 10mm, the length of the annular solid portion (19) is 15mm or more, the wall thickness of the first upper annular portion (20) and the wall thickness of the first lower annular portion (21) are both 4mm or more, the thickness of the first lower annular portion (21) is 10mm to 20mm, and the height of the first lower annular portion (21) is 30mm to 50 mm.

11. The deposition apparatus according to claim 5, wherein the second upper annular portion (22) has a length of 20mm to 40mm, the second upper annular portion (22) has a thickness of 13mm to 18mm, the annular solid portion (19) has a thickness of 5mm to 10mm, the annular solid portion (19) has a length of 15mm or more, the second upper annular portion (22) has a wall thickness of 4mm or more, the second lower annular portion (23) has a thickness of 10mm to 20mm, and the second lower annular portion (23) has a height of 30mm to 50 mm.

12. The deposition apparatus according to claim 1, wherein the upper surface (602) of the upper electrode (6) is provided with a sunken recess (603) for adjusting the inner space of the upper electrode (6).

13. The deposition apparatus of claim 1, wherein the liquid media material comprises one of cyclo-ethanol, edible oil, kerosene, methanol, glycerol, water, and ethanol.

Technical Field

The invention belongs to the field of semiconductor manufacturing equipment, and particularly relates to deposition equipment.

Background

Plasma Enhanced Chemical Vapor Deposition (PECVD) equipment ionizes gas containing film component atoms by means of Radio Frequency (RF) tools and the like to form Plasma, and SiO can be deposited on the surface of a wafer by using corresponding process gas due to strong chemical activity of the Plasma₂And a film of SiNx or SiON. Low film forming temperature and deposition rate based on PECVD equipmentThe device has the advantages of high speed, good film forming quality and the like, and is generally applied to the related semiconductor fields of light emitting diodes, micro electro mechanical systems, integrated circuits and the like at present.

The PECVD equipment has various types such as a single-station type and a multi-station type, wherein the single-station type flat plate type capacitive coupling discharge plasma equipment has the advantages of large-area bearing substrates, good uniformity of deposited films and the like, and becomes one of the common equipment in the industries of semiconductors, photovoltaics and the like. In the design process, it is found that the isolation capacitance at the position of the isolation ring not only affects the voltage isolation effect, but also plays an important role in plasma ignition in the chamber. The isolation capacitors not only affect the ignition problem, but also change the process gas dissociation degree and the vibrating electron temperature in the reaction chamber.

Fig. 1 shows a schematic view of a deposition apparatus in the prior art. As shown in fig. 1, in the upper electrode rf feeding system in the prior art, the upper electrode is excited in a plate capacitive coupling manner to generate plasma, and a hollow structure is disposed inside the upper electrode 6, and the lower surface 601 has uniformly distributed air holes to ensure that the gas uniformly flows into the reaction chamber. The radio frequency radiation generated by the upper electrode 6 is shielded by the shielding member 2 to reduce the radio frequency radiation and reduce the harm to the human body. The isolation ring 101 and the focus ring 102 physically isolate the upper electrode 6 from the support ring, preventing sparking between the upper electrode 6 and the support ring 5. The structure size of the isolating ring in the prior art is fixed, and the used material is single, so that the isolating capacitor at the position is fixed and is not easy to change, and if the capacitance value at the position is required to be changed, the material needs to be additionally changed for processing and installation.

Accordingly, it is desirable to provide a deposition apparatus having an isolation ring capable of varying an isolation capacitance to achieve control of a gas dissociation degree and an electron temperature of a plasma.

Disclosure of Invention

The invention aims to provide an isolating ring for a deposition device and the deposition device thereof, wherein the isolating ring can replace liquid medium materials with different dielectric constants so as to change the isolating capacitance of the isolating ring.

In order to achieve the aim, the deposition equipment comprises a reaction chamber, an upper electrode, a support ring, a separation ring and a focusing ring, wherein the upper electrode, the support ring, the separation ring and the focusing ring are positioned in the reaction chamber and are coaxially arranged with the reaction chamber; the inner part of the isolating ring is provided with a cavity which is used for containing liquid medium materials; the liquid inlet channel and the liquid discharge channel are arranged in the support ring and communicated with the cavity, the liquid inlet channel is used for conveying the liquid medium materials into the cavity, and the liquid discharge channel is used for discharging the liquid medium materials in the cavity.

Preferably, the spacer ring comprises a first upper annular portion and a first lower annular portion, the first upper annular portion extending radially outwardly along a top of the first lower annular portion;

the cavity comprises a first annular cavity arranged in the first upper annular part and a second annular cavity arranged in the first lower annular part, and the second annular cavity is communicated with the first annular cavity.

Preferably, the spacer ring comprises a second upper annular portion and a second lower annular portion, the second upper annular portion extending from a top of the second lower annular portion radially outward of the second lower annular portion;

the cavity includes a third annular cavity disposed within the second upper annular portion.

Preferably, the isolating ring further includes an annular solid portion located at an outer periphery of the first upper annular portion, and an upper end surface of the annular solid portion is lower than an upper end surface of the first upper annular portion.

Preferably, the isolating ring further includes an annular solid portion located at an outer periphery of the second upper annular portion, and an upper end surface of the annular solid portion is lower than an upper end surface of the second upper annular portion.

Preferably, the upper electrode includes an upper end portion and a lower end portion, an edge of the upper end portion has a downward projection, and a lower end surface of the projection is in contact with an upper end surface of the annular solid portion.

Preferably, a liquid inlet and a liquid outlet which are communicated with the third annular cavity are formed in the bottom of the second upper annular part, one end of the liquid inlet channel is connected with the liquid inlet, and the other end of the liquid inlet channel is provided with a liquid inlet valve and extends to the outside of the reaction chamber; one end of the liquid discharge channel is connected with the liquid discharge port, and the other end of the liquid discharge channel is provided with a liquid discharge valve and extends to the outside of the reaction chamber.

Preferably, a liquid inlet and a liquid outlet which are communicated with the first annular cavity are formed in the bottom of the first upper annular part, one end of the liquid inlet channel is connected with the liquid inlet, and the other end of the liquid inlet channel is provided with a liquid inlet valve and extends to the outside of the reaction chamber; one end of the liquid discharge channel is connected with the liquid discharge port, a liquid discharge pipe is arranged in the liquid discharge channel, one end of the liquid discharge pipe extends to the bottom end of the second annular cavity through the liquid discharge port, the other end of the liquid discharge channel extends to the outside of the reaction chamber, and the other end of the liquid discharge pipe extends to the outside of the reaction chamber and is provided with a liquid discharge pump.

Preferably, the drain pipe is made of an insulating material.

Preferably, the length of the first upper annular portion is 20mm to 40mm, the thickness of the first upper annular portion is 13mm to 18mm, the thickness of the annular solid portion is 5mm to 10mm, the length of the annular solid portion is 15mm or more, the wall thickness of the first upper annular portion and the wall thickness of the first lower annular portion are both greater than or equal to 4mm, the thickness of the first lower annular portion is 10mm to 20mm, and the height of the first lower annular portion is 30mm to 50 mm.

Preferably, the length of the second upper annular portion is 20mm to 40mm, the thickness of the second upper annular portion is 13mm to 18mm, the thickness of the annular solid portion is 5mm to 10mm, the length of the annular solid portion is 15mm or more, the wall thickness of the second upper annular portion is 4mm or more, the thickness of the second lower annular portion is 10mm to 20mm, and the height of the second lower annular portion is 30mm to 50 mm.

Preferably, a sinking groove is formed in the upper surface of the upper electrode, and is used for adjusting the inner space of the upper electrode.

Preferably, the liquid medium material comprises one of cyclo-ethanol, edible oil, kerosene, methanol, glycerol, water and ethanol.

The invention has the beneficial effects that: the cavity of the isolating ring can contain liquid medium materials, and the isolating capacitance of the isolating ring can be changed by replacing liquid media with different dielectric constants in the cavity of the isolating ring, so that the gas dissociation degree and the electron temperature of plasma can be controlled.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The invention will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Fig. 1 shows a schematic view of a deposition apparatus in the prior art.

Fig. 2 shows a schematic structural view of a deposition apparatus according to an embodiment of the present invention.

Fig. 3 shows a schematic structural view of a spacer ring according to an embodiment of the present invention.

Fig. 4 shows a schematic structural view of a deposition apparatus according to another embodiment of the present invention.

Fig. 5 shows a schematic structural view of a spacer ring according to another embodiment of the present invention.

FIG. 6(a) shows N₂And (3) a trend graph of the dissociation degree of the gas along with the change of the power.

FIG. 6(b) shows N₂Trend graph of vibration electron temperature of gas with power change.

Description of reference numerals:

2. a shield; 3. an upper electrode connecting strip; 4. a shielding cylinder; 5. a support ring; 6. an upper electrode; 7. a chamber wall; 8. a liner; 9. a lower electrode; 10. a lower electrode connecting strip; 11. an air extraction opening; 12. a plasma region; 13. a liquid inlet valve; 14. a liquid outlet valve; 15. an isolating ring; 16. a liquid inlet channel; 17. a liquid outlet channel; 19. an annular solid portion; 20. a first upper annular portion; 21. a first lower annular portion; 22. a second upper annular portion; 23. a second lower annular portion; 24. a first annular cavity; 25. a second upper annular portion; 26. a third annular cavity; 27. a liquid discharge pipe; 102. a focus ring; 601. a lower surface of the upper electrode; 602. an upper surface of the upper electrode; 603. sinking the groove; 101. and a spacer ring.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The isolation capacitance of the isolation ring affects the electron density of the plasma, the process gas dissociation degree, the vibrating electron temperature, and the like. Since the isolation ring of the existing device uses a solid design, once the design is completed, the isolation capacitor cannot be changed at will. The isolation capacitor at this position plays an important role because the size of the isolation capacitor can control the gas dissociation degree and the vibrating electron temperature of the plasma in the chamber, and can also influence the starting window of the device. If the process is required to be carried out under different isolation capacitance values, the existing equipment is difficult to realize, different materials can only be replaced when the size of the isolation capacitor is required to be changed, the isolation capacitor is not only limited by the types of the materials, but also the isolation rings made of different materials are required to be replaced, and the isolation capacitors are required to be independently processed and installed.

A deposition apparatus according to an embodiment of the present invention includes: the device comprises a reaction chamber, an upper electrode, a support ring, an isolation ring and a focusing ring, wherein the upper electrode, the support ring, the isolation ring and the focusing ring are positioned in the reaction chamber and are coaxial with the reaction chamber; the inner part of the isolating ring is provided with a cavity which is used for containing liquid medium materials; the liquid inlet channel and the liquid discharge channel are arranged in the support ring and communicated with the cavity, the liquid inlet channel is used for conveying liquid medium materials into the cavity, and the liquid discharge channel is used for discharging the liquid medium materials in the cavity.

In the embodiment of the invention, the cavity structure in the isolating ring can contain liquid medium materials, and insulating liquid media with different dielectric constants r can be introduced into the cavity structure. According to the relation between the dielectric constant and the isolation capacitance_rs/d, wherein,_rthe dielectric constant is represented, the area of the upper electrode opposite to the lower electrode is represented by s, the distance between the upper electrode and the lower motor is represented by d, and the direct proportional relation between the isolation capacitance and the dielectric constant of the material can be known, so that liquid media with different dielectric constants are introduced into the isolation ring, the change of the isolation capacitance at the position can be realized, and the control of the gas dissociation degree and the electron temperature of the plasma can be realized.

In the embodiment of the invention, the liquid inlet channel and the liquid outlet channel which are communicated with the cavity are arranged in the support ring, the liquid inlet channel is used for filling the liquid medium material into the cavity, the liquid outlet channel is used for discharging the liquid medium material in the cavity, the liquid medium material can be introduced into the cavity through the liquid inlet channel, so that the isolation capacitance of the isolation ring is changed, the liquid medium material in the cavity can be discharged through the liquid outlet channel, the liquid medium material of the isolation ring is convenient to replace, and the isolation capacitance of the isolation ring has adjustability.

The isolating ring is arranged in a reaction chamber of the deposition equipment, the outer peripheral wall between the upper electrode and the support ring is sleeved with the isolating ring, and the isolating ring and the focusing ring are used for physically isolating the upper electrode from the support ring, so that the problem of sparking between the upper electrode and the support ring is prevented.

As an example, in order to ensure the good isolation effect of the isolation ring, the isolation ring is made of ceramic materials, and meanwhile, the axial section of the isolation ring is designed to be of an inverted L-shaped structure, so that the safety protection range is enlarged.

As an example, the isolating ring of the embodiment is of an annular structure, the axial section of the isolating ring is inverted L, the isolating ring is hollow, and an annular cavity is arranged inside the isolating ring and used for containing liquid medium materials.

More preferably, the axial cross-section of the spacer ring also includes other annular structures that can cooperate with the upper electrode, such as an F-shape, a Z-shape, etc.

A spacer ring of this embodiment, comprising: a first upper annular portion and a first lower annular portion, the first upper annular portion extending radially outward along a top of the first lower annular portion; the cavity is including locating the first annular cavity in the first upper annular portion and locating the second annular cavity in the first lower annular portion, and the second annular cavity is linked together with first annular cavity. The first annular cavity and the second annular cavity form a complete liquid medium material filling area, and liquid medium materials with different dielectric constants can be filled in the first annular cavity and the second annular cavity.

Preferably, the spacer ring further includes an annular solid portion located at an outer periphery of the first upper annular portion, and an upper end surface of the annular solid portion is lower than an upper end surface of the first upper annular portion. The upper electrode includes an upper end portion and a lower end portion, an edge of the upper end portion has a downward projection, and a lower end surface of the projection is in contact with an upper end surface of the annular solid portion.

In order to bear the weight of the upper electrode, the above embodiment is to provide the annular solid portion on the outer periphery of the first upper annular portion, and the weight of the upper electrode is supported by the annular solid portion, so as to prevent the first annular cavity from being damaged by the self weight of the upper electrode. The upper end face of the annular solid part is lower than the upper end face of the first upper annular part, and the upper end face of the annular solid part is matched with the edge of the protruding part of the upper electrode, so that the stability of fixing the upper electrode and the isolating ring is improved.

As a preferred scheme, the bottom of the first upper annular part is provided with a liquid inlet and a liquid outlet which are communicated with the first annular cavity, one end of a liquid inlet channel is connected with the liquid inlet, and the other end of the liquid inlet channel is provided with a liquid inlet valve and extends to the outside of the reaction chamber; one end of the liquid discharge channel is connected with the liquid discharge port, a liquid discharge pipe is arranged in the liquid discharge channel, one end of the liquid discharge pipe extends to the bottom end of the second annular cavity through the liquid discharge port, the other end of the liquid discharge channel extends to the outside of the reaction chamber, and the other end of the liquid discharge pipe extends to the outside of the reaction chamber and is provided with a liquid discharge pump.

The bottom that second toroidal cavity was stretched into to fluid-discharge tube one end in the flowing back pipeline can be arranged the liquid medium material in the second toroidal cavity to the greatest extent, avoids the bottom of second toroidal cavity to have residual liquid, and the other end of fluid-discharge tube extends to reaction chamber's outside to set up the flowing back pump, improve the flowing back efficiency of liquid medium material.

As an example, the other end of the liquid inlet channel is provided with a liquid inlet valve and extends to the outside of the reaction chamber; and/or the other end of the liquid outlet channel is provided with a liquid outlet valve and extends to the outside of the reaction chamber, so that the liquid medium material can be conveniently controlled to be introduced into or discharged from the cavity. During normal use of the device, the liquid inlet valve and the liquid outlet valve are kept in a closed state, when different liquid medium materials need to be replaced, the liquid inlet valve and the liquid outlet valve are firstly opened, and the inner part of the isolation ring is completely blown by inert gas, such as N₂And through a liquid discharge pump and a liquid discharge pipe, cleaning residual liquid at the bottom of the second annular cavity, then introducing the liquid medium material with the required dielectric constant again, and finally closing the liquid inlet valve and the liquid outlet valve.

As an example, the liquid inlet and the liquid outlet are arranged at the bottom of the first upper annular part, and the sealing component is arranged between the bottom of the first upper annular part and the upper end surface of the support ring, so that the sealing performance of the joint of the liquid inlet channel and the liquid inlet and the sealing performance of the joint of the liquid outlet channel and the liquid outlet are ensured, and liquid leakage of liquid medium materials in the cavity is avoided.

As the preferred scheme, the drain pipe is made of insulating materials such as rubber, the physical isolation effect of the isolation ring is guaranteed, and the ignition between the upper electrode and the support ring is avoided.

The size of the spacer ring is designed according to the size of the upper electrode. Preferably, the length of the first upper annular portion is 20mm to 40mm, the thickness of the first upper annular portion is 13mm to 18mm, the thickness of the annular solid portion is 5mm to 10mm, the length of the annular solid portion is 15mm or more, the wall thickness of the first upper annular portion and the wall thickness of the first lower annular portion are both 4mm or more, the thickness of the first lower annular portion is 10mm to 20mm, and the height of the first lower annular portion is 30mm to 50 mm.

As an example, the increase in height of the lower annular portion may result in an increase in the internal space of the upper electrode in the prior art, and in order to maintain the same size as the space in the upper electrode in the prior art, the upper surface of the upper electrode may be subjected to sinking processing in the present embodiment. For example, a sinking groove may be provided on the upper surface of the upper electrode for adjusting the inner space of the upper electrode.

Another isolating ring of the embodiment comprises a second upper annular part and a second lower annular part, wherein the second upper annular part extends outwards from the top of the second lower annular part along the radial direction of the second lower annular part; the cavity includes a third annular cavity disposed within the second upper annular portion.

Through the inside third annular cavity that is equipped with of annular portion on the second, its inside liquid dielectric material that can fill different dielectric constants, annular portion is the solid structure under the second, simplifies the structure, prevents the hydrops.

Preferably, the spacer ring further includes an annular solid portion located on an outer periphery of the second upper annular portion, and an upper end surface of the annular solid portion is lower than an upper end surface of the second upper annular portion. The upper electrode includes an upper end portion and a lower end portion, an edge of the upper end portion has a downward projection, and a lower end surface of the projection is in contact with an upper end surface of the annular solid portion.

In order to bear the weight of the upper electrode, the above embodiment needs to provide an annular solid portion on the outer periphery of the second upper annular portion, and the weight of the upper electrode is supported by the annular solid portion, so as to prevent the third annular cavity from being damaged by the weight of the upper electrode itself. The upper end face of the annular solid part is lower than the upper end face of the second upper annular part, and the lower end face of the protruding part is in contact with the upper end face of the annular solid part, so that the upper end face of the annular solid part is matched with the edge of the protruding part of the upper electrode, and the stability of fixing the upper electrode and the isolating ring is improved.

As a preferred scheme, the bottom of the second upper annular part is provided with a liquid inlet and a liquid outlet which are communicated with the third annular cavity, one end of a liquid inlet channel is connected with the liquid inlet, and the other end of the liquid inlet channel is provided with a liquid inlet valve and extends to the outside of the reaction chamber; one end of the liquid discharge channel is connected with the liquid discharge port, the other end of the liquid discharge channel is provided with a liquid outlet valve and extends to the outside of the reaction chamber, and the liquid medium material is conveniently controlled to be introduced into the cavity to be communicated and closed.

As an example, during normal use of the apparatus, the inlet and outlet valves are kept closed, and when it is necessary to replace different liquid medium materials, the inlet and outlet valves are first opened and the inside of the isolation ring is purged with an inert gas, such as N₂Then the liquid medium material with the required dielectric constant is introduced again, and finally the liquid inlet valve and the liquid outlet valve are closed.

As an example, the liquid inlet and the liquid outlet are arranged at the bottom of the second upper annular part, and a sealing component is arranged between the bottom of the second upper annular part and the upper end surface of the support ring, so that the sealing performance of the joint of the liquid inlet channel and the liquid inlet and the sealing performance of the joint of the liquid outlet channel and the liquid outlet are ensured, and liquid leakage of liquid medium materials in the cavity is avoided.

The size of the spacer ring is designed according to the size of the upper electrode. Preferably, the length of the second upper annular portion is 20mm to 40mm, the thickness of the second upper annular portion is 13mm to 18mm, the thickness of the annular solid portion is 5mm to 10mm, the length of the annular solid portion is 15mm or more, the wall thickness of the second upper annular portion is 4mm or more, the thickness of the second lower annular portion is 10mm to 20mm, and the height of the second lower annular portion is 30mm to 50 mm.

Preferably, in order to maintain the consistency of the size of the space in the upper electrode in the prior art, the upper surface of the upper electrode is provided with a sinking groove for adjusting the inner space of the upper electrode.

Preferably, the dielectric material can be, but is not limited to, one of cyclo-ethanol, edible oil, kerosene, methanol, glycerol, water and ethanol.

Table 1 shows the dielectric constants of several common liquid dielectric materials

Media name	Dielectric constant
		Cycloethanol	2
Edible oil	2～4
		Kerosene oil	2.8
Methanol	30
		Glycerol	37
Water (W)	81
		Ethanol	24

As an example, process results were tested and compared for isolation capacitance of the isolation ring. Using N under two different isolation capacitance conditions₂FIG. 6(a) shows N as a glow-starting gas₂The dissociation degree of the gas is changed with the power, and the ignition data is shown in FIG. 6(a), and it can be seen that the power is increased from 50W to 300W, and the isolation capacitance is N at 920pF₂The dissociation of the gas is always greater than 548pF, indicating that varying the isolation capacitance can adjust the dissociation of the gas in the reaction chamber. FIG. 6(b) shows N₂The trend of the vibrating electron temperature of the gas with the power can be seen, when the power is increased from 50W to 300W, the isolation capacitance is 920pFThe electron temperature is always less than 548pF, indicating that changing the isolation capacitance can also adjust the electron temperature of the gas in the reaction chamber. Table 2 shows a comparison of the composition of some common particles, where the isolation capacitance of 920pF had both greater H and SiH composition than 548 pF.

At the same time, to SiO₂Tests are carried out with the SiNx film layer deposition process, and the finding that the SiO can be improved by the high isolation capacitance value₂And refractive index of the SiNx film layer. The results of the above process tests show that for SiO₂The refractive index of the process film layer is increased from 1.472 to 1.477, and the refractive index of the SiNx process film layer is increased from 1.896 to 2.023.

In practical application, the starting gas can be replaced as required, and the isolation capacitance of the isolation ring can be changed within the power variation range.

TABLE 2 comparison of spectral data under different isolation capacitance values for process conditions

Parameter(s)	Isolation capacitor 560pF	Isolation capacitor 920pF
			Degree of dissociation (N/N)2)	0.07	0.08
Plasma composition (H/(Si + SiH + H))	0.331	0.343
			Plasma composition (SiH/(Si + SiH + H))	0.23	0.235
Plasma composition (Si/(Si + SiH + H))	0.439	0.422
			Vibrating electron temperature	0.675	0.63

Therefore, according to the above example, the isolation capacitance can be adjusted by introducing different liquid dielectric materials into the annular cavity, so that the adjustability of the dissociation degree of the gas and the electron temperature can be realized.