JP7073710B2 - Plasma processing equipment - Google Patents

Description

The present invention relates to a technique for performing plasma treatment of a substrate to be treated with a plasma-generated processing gas.

In the manufacturing process of a flat panel display (FPD) such as a liquid crystal display (LCD), a plasma-generated processing gas is supplied to a glass substrate, which is a substrate to be processed, placed in a processing space for etching. There is a process of performing plasma processing such as film formation processing. Various plasma processing devices such as a plasma etching device and a plasma CVD device are used for these plasma treatments.

On the other hand, the size of the glass substrate is increasing. For example, in a rectangular glass substrate for LCD, the required amount is required for each position in the surface to be processed, which has a length of short side x long side of about 2200 mm x about 2400 mm, and further has a size of about 2800 mm x about 3000 mm. It is necessary to supply the treatment gas of the above and to perform uniform treatment in the plane of the glass substrate.

On the other hand, as the size of the glass substrate increases, the concentration of the processing gas reaching the glass substrate, the state of plasma formation, and the like may change significantly in the surface to be processed. Therefore, there is a problem that the processing state of the glass substrate by the processing gas becomes non-uniform in the plane.
Further, it may be difficult to supply a required amount of processing gas to each position of such a large glass substrate.

For example, in Patent Document 1, the inside of the shower head is divided concentrically to provide, for example, three buffer chambers, and plasma is divided into these buffer chambers from a common gas supply source and plasma is processed in the processing container in which the substrate is processed. A technique for supplying an etching gas for etching is described. According to Patent Document 1, of the above-mentioned buffer chambers, the etching gas supplied to the two buffer chambers on the peripheral portion side is supplied with an additional gas for adjusting the etching characteristics, thereby supplying the substrate surface. The concentration of the etching gas is locally adjusted within.
However, in the technique described in Patent Document 1, when supplying the additional gas, a dedicated gas supply source is provided for each etching gas supply path to each buffer chamber, so that the configuration of the gas supply source may become large. be.

Japanese Patent No. 4358727: Claim 1, paragraphs 0004, 0028, 0049 to 0050, FIG.

The present invention has been made under such circumstances, and an object thereof is to be able to adjust the components of the processing gas for each of a plurality of gas shower head units while using a common processing gas raw material supply unit. The purpose is to provide a plasma processing apparatus.

The plasma processing apparatus of the first invention is a plasma processing apparatus that executes plasma processing with a plasma-ized processing gas on a substrate to be processed in a vacuum-exhausted processing space.
A processing container provided with a mounting table on which the substrate to be processed is placed and constituting a processing space in which the plasma processing is performed, and a processing container.
A gas discharge that constitutes the ceiling surface of the processing space and is provided in each of a plurality of regions formed by dividing the ceiling surface from the central portion side to the peripheral portion side in the radial direction to supply the processing gas to the processing space. Multiple gas shower heads with holes and
A plasma generating unit for converting the processing gas supplied to the processing space from the plurality of gas shower head units into plasma, and a plasma generating unit.
A first processing gas raw material supply unit for supplying a first processing gas raw material and a second processing gas raw material supply unit for supplying a second processing gas raw material contained in the processing gas.
A first supply flow rate adjusting unit for adjusting the flow rate of the first processing gas raw material supplied to the processing space from the first processing gas raw material supply unit.
The first processing gas raw material whose flow rate has been adjusted by the first supply flow rate adjusting unit is provided in each of a plurality of first distribution channels for distributing and supplying the first processing gas raw material to the plurality of gas shower head units. A plurality of first distribution flow rate adjusting units for adjusting the flow rate of the first raw material gas supplied to each gas shower head unit, and
A second supply flow rate adjusting unit for adjusting the flow rate of the second processing gas raw material supplied to the processing space from the second processing gas raw material supply unit.
The second processing gas raw material whose flow rate has been adjusted by the second supply flow rate adjusting unit is provided in each of the plurality of second distribution channels for distributing and supplying the second processing gas raw material to the plurality of gas shower head units. A plurality of second distribution flow rate adjusting units for adjusting the flow rate of the second raw material gas supplied to each gas shower head unit are provided .
The processing gas is an etching gas for etching the etching target film formed on the substrate to be processed, which is a glass substrate.
The second processing gas raw material is oxygen gas, and
The first and second distribution flow rate adjusting units provided in the plurality of first and second distribution flow paths have a magnitude of inclination of the end portion of the photoresist film patterned on the upper surface side of the etching target film. The first and second processing gas raw materials are such that the oxygen concentration of the etching gas supplied from the gas shower head portion at the position where the etching gas is supplied to these regions is changed according to the regions in which the etching gas is different. It is characterized by the fact that the flow rate is set .
Further, the plasma processing apparatus of the second invention is a plasma processing apparatus that executes plasma processing with a plasma-generated processing gas on a substrate to be processed in a vacuum-exhausted processing space.
A processing container provided with a mounting table on which the substrate to be processed is placed and constituting a processing space in which the plasma processing is performed, and a processing container.
A gas discharge that constitutes the ceiling surface of the processing space and is provided in each of a plurality of regions formed by dividing the ceiling surface from the central portion side to the peripheral portion side in the radial direction to supply the processing gas to the processing space. Multiple gas shower heads with holes and
A plasma generating unit for converting the processing gas supplied to the processing space from the plurality of gas shower head units into plasma, and a plasma generating unit.
A first processing gas raw material supply unit for supplying a first processing gas raw material and a second processing gas raw material supply unit for supplying a second processing gas raw material contained in the processing gas.
A first supply flow rate adjusting unit for adjusting the flow rate of the first processing gas raw material supplied to the processing space from the first processing gas raw material supply unit.
The first processing gas raw material whose flow rate has been adjusted by the first supply flow rate adjusting unit is provided in each of a plurality of first distribution channels for distributing and supplying the first processing gas raw material to the plurality of gas shower head units. A plurality of first distribution flow rate adjusting units for adjusting the flow rate of the first raw material gas supplied to each gas shower head unit, and
A second supply flow rate adjusting unit for adjusting the flow rate of the second processing gas raw material supplied to the processing space from the second processing gas raw material supply unit.
The second processing gas raw material whose flow rate has been adjusted by the second supply flow rate adjusting unit is provided in each of the plurality of second distribution channels for distributing and supplying the second processing gas raw material to the plurality of gas shower head units. A plurality of second distribution flow rate adjusting units for adjusting the flow rate of the second raw material gas supplied to each gas shower head unit are provided.
The processing gas is an etching gas for etching an aluminum film formed on a substrate to be processed, which is a glass substrate, and a silicon dioxide film on the upper layer side thereof.
The first processing gas raw material is chlorine gas, and the second processing gas raw material is nitrogen gas and halogen-containing gas.
The first and second distribution flow rate adjusting units provided in the plurality of first and second distribution flow paths are located on the central portion side of the gas shower head portion located on the peripheral portion side of the ceiling surface. The flow rate of the first and second processing gas raw materials is set so that the distribution ratio of the nitrogen gas and the halogen-containing gas to the chlorine gas of the etching gas supplied from the gas shower head portion becomes small, respectively. And, it is characterized by.
Further, the plasma processing apparatus of the third invention is a plasma processing apparatus that executes plasma processing with a plasma-ized processing gas on a substrate to be processed in a vacuum-exhausted processing space.
A processing container provided with a mounting table on which the substrate to be processed is placed and constituting a processing space in which the plasma processing is performed, and a processing container.
A gas discharge that constitutes the ceiling surface of the processing space and is provided in each of a plurality of regions formed by dividing the ceiling surface from the central portion side to the peripheral portion side in the radial direction to supply the processing gas to the processing space. Multiple gas shower heads with holes and
A plasma generating unit for converting the processing gas supplied to the processing space from the plurality of gas shower head units into plasma, and a plasma generating unit.
A first processing gas raw material supply unit for supplying a first processing gas raw material and a second processing gas raw material supply unit for supplying a second processing gas raw material contained in the processing gas.
A first supply flow rate adjusting unit for adjusting the flow rate of the first processing gas raw material supplied to the processing space from the first processing gas raw material supply unit.
The first processing gas raw material whose flow rate has been adjusted by the first supply flow rate adjusting unit is provided in each of a plurality of first distribution channels for distributing and supplying the first processing gas raw material to the plurality of gas shower head units. A plurality of first distribution flow rate adjusting units for adjusting the flow rate of the first raw material gas supplied to each gas shower head unit, and
A second supply flow rate adjusting unit for adjusting the flow rate of the second processing gas raw material supplied to the processing space from the second processing gas raw material supply unit.
The second processing gas raw material whose flow rate has been adjusted by the second supply flow rate adjusting unit is provided in each of the plurality of second distribution channels for distributing and supplying the second processing gas raw material to the plurality of gas shower head units. A plurality of second distribution flow rate adjusting units for adjusting the flow rate of the second raw material gas supplied to each gas shower head unit are provided.
The processing gas is a film forming gas for forming a silicon-containing film formed on a substrate to be processed, which is a glass substrate.
The first processing gas raw material is at least one of silicon tetrafluoride gas and silicon tetrachloride gas, and the second processing gas raw material is nitrogen gas or oxygen gas.
The second distribution flow path merges with the first distribution flow path on the downstream side of the first distribution flow rate adjusting unit, respectively.
In the first distribution flow rate adjusting unit and the first distribution flow rate adjustment unit, the pressure in the flow path from the first distribution flow rate adjustment unit to the first distribution flow rate adjustment unit is the first at room temperature. It is characterized in that the flow rate is set so as to supply the first processing gas raw material having a flow rate maintained at a pressure lower than the vapor pressure of the processing gas raw material.

In the present invention, each of the first and second processed gas raw material supply units is provided with first and second supply flow rate adjusting units for adjusting the flow rate of the first and second processed gas raw materials, and further, a plurality of supply flow rate adjusting units are provided. The first and second distribution flow rate adjusting units are also provided for the plurality of first and second distribution channels for distributing the first and second processed gas raw materials to the gas shower head unit, respectively. ing. As a result, the first and second processed gas raw materials obtained from the common first and second processed gas raw material supply units can be mixed at an arbitrary ratio and supplied to each position of the substrate to be processed. ..

It is 1st explanatory drawing of the substrate to be processed which is processed by the plasma processing apparatus which concerns on embodiment. It is a 2nd explanatory drawing of the substrate to be processed which is processed by a plasma processing apparatus. It is a vertical sectional side view of a plasma processing apparatus. It is a top view of the metal window provided in the plasma processing apparatus. It is a supply system diagram of the etching gas to each gas shower head part which constitutes the metal window. It is 1st explanatory drawing concerning the other substrate to be processed which is processed by a plasma processing apparatus. It is a 2nd explanatory drawing which concerns on the said other substrate to be processed. It is explanatory drawing of the substrate to be processed which is processed by the plasma processing apparatus which concerns on 2nd Embodiment. It is a supply system diagram of the processing gas to the plasma processing apparatus which concerns on 2nd Embodiment. It is a supply system diagram of the processing gas to the plasma processing apparatus which concerns on 3rd Embodiment. It is explanatory drawing which shows the pressure at each position in the supply flow path of a processing gas. It is a temperature-vapor pressure characteristic diagram of _SiCl4 gas.

Before explaining the specific configuration of the plasma processing apparatus 1 according to the embodiment of the present invention, the example of the plasma processing performed by the plasma processing apparatus 1 and the problems grasped in the implementation of the process processing will be discussed. This will be described with reference to FIGS. 1 and 2.
FIGS. 1 and 2 show enlarged vertical sectional side views of different regions of the upper surface (processed surface) of the substrate G to be processed. In the substrate G to be processed, a SiO film 702 and a SiN film 703, both of which are silicon-containing films, are laminated in this order on a glass substrate 701, and an exposure-developed photoresist film 704 is further formed on the upper surface of the SiN film 703. Is patterned.

For example, the substrate G to be processed is composed of a rectangular glass substrate 701 for FPD. Here, examples of the FPD include a liquid crystal display (LCD), an electroluminescence (EL) display, and a plasma display panel (PDP).

With respect to the substrate G to be processed, at least one of carbon tetrafluoride (CF ₄ ) gas or nitrogen trifluoride (NF ₃ ) gas, which is a raw material for the first processing gas, and oxygen, which is a raw material for the second processing gas. (O ₂ ) By supplying the etching gas containing the gas as plasma, the SiO resist film 704 is gradually ashed, and the SiO film 702 and the SiN film 703 in the region not covered by the photoresist film 704 are removed. Etching process is performed. The SiO film 702 and the SiN film 703 correspond to the etching target film of the present embodiment.

Regarding the above-mentioned treatment, the present inventors have different vertical cross-sectional shapes of the patterned photoresist film 704 depending on the position of the substrate G to be treated in the surface to be treated, and as a result, the result of the etching treatment is different. I found that there was a tendency.

For example, in the photoresist film 704 formed on the peripheral side of the substrate G to be processed, the inclination (taper angle) of the end portion of the photoresist film 704 after patterning as shown in FIG. 1A is large. May be.

The concentration (divided pressure) of the O ₂ gas is low (for example, the flow ratio of the O ₂ gas / CF ₄ gas is 1: 3) with respect to the portion where the inclination of the end portion of the photoresist film 704 after the patterning is large. When the etching process is performed using the etching gas of No. 1, the SiO film 702 and the SiN film 703 on the glass substrate 701 are removed by etching in good condition as shown in FIG. 1 (b).
On the other hand, when the etching process is performed using an etching gas having a high concentration of O ₂ gas (for example, a flow ratio of O ₂ gas / CF ₄ gas is 3: 2), the SiO film 702 is shown in FIG. 1 (c). At the end of the SiN film 703, a residue having a shape depending on the taper angle of the photoresist film 704 (taper residue 71a) or a small needle-shaped etching residue 71b may remain.

Further, for example, in the photoresist film 704 formed on the central portion side of the substrate G to be processed, the inclination (taper angle) of the end portion of the photoresist film 704 after patterning as shown in FIG. 2A is set. It may be smaller.

The concentration of O ₂ gas is low with respect to the portion where the inclination of the end portion of the photoresist film 704 after patterning is small (for example, the flow rate of O ₂ gas / CF ₄ gas as in the case of FIG. 1 (b)). When the etching process was performed using the etching gas of the ratio), as shown in FIG. 2 (b), a needle-shaped etching residue 71b was attached to the ends of the SiO film 702 and the SiN film 703 removed from the glass substrate 701. There was a tendency for the gas to remain.
On the other hand, when the etching process is performed using an etching gas having a high concentration of O ₂ gas (for example, the flow ratio of O ₂ gas / CF ₄ gas similar to that in FIG. 1 (c)), FIG. 2 (c) shows. As shown, the SiO film 702 and the SiN film 703 on the glass substrate 701 are removed by etching in good condition.

According to the correspondence between the concentration of the O ₂ gas in the etching gas described above and the result of the etching treatment at each position of the substrate G to be processed, a good etching treatment result is obtained on the peripheral portion side of the substrate G to be processed. When an etching gas having a low concentration of O ₂ gas is supplied to the entire surface of the substrate G to be processed, needle-like particles are formed at the ends of the SiO film 702 and the SiN film 703 on the central portion side of the substrate G to be processed. The etching residue 71b may remain.

Further, in order to obtain a good etching treatment result on the central portion side of the substrate G to be processed, when an etching gas having a high concentration of O ₂ gas is supplied to the entire surface of the substrate G to be processed, the peripheral portion side of the substrate G to be processed is supplied. There is a possibility that the taper residue 71a and the needle-shaped etching residue 71b may remain at the ends of the SiO film 702 and the SiN film 703.
In order to deal with the problems described above, the plasma processing apparatus 1 according to the present embodiment has a configuration capable of changing the concentration of the O ₂ gas in the etching gas according to the position of the substrate G to be processed. It has become.

The configuration of the plasma processing apparatus 1 according to the embodiment of the present invention will be described with reference to FIGS. 3 and 4.
As shown in the vertical sectional side view of FIG. 3, the plasma processing apparatus 1 includes a square cylinder-shaped container body 10 made of a conductive material, for example, aluminum whose inner wall surface has been anodized, and the container body 10 is electric. Is grounded. An opening is formed on the upper surface of the container body 10, and this opening is airtightly closed by a rectangular metal window 3 provided so as to be insulated from the container body 10.

The space surrounded by the container body 10 and the metal window 3 becomes the processing space 100 of the substrate G to be processed. The space above the metal window 3 is an antenna chamber 50 in which the high-frequency antenna (plasma antenna) 5 is arranged.
Further, on the side wall of the container main body 10, a carry-in outlet 101 for carrying in and out the substrate G to be processed and a gate valve 102 for opening and closing the carry-in outlet 101 are provided.

On the lower side of the processing space 100, a mounting table 13 for mounting the substrate G to be processed is provided so as to face the metal window 3. The mounting table 13 is made of a conductive material, for example, aluminum whose surface has been anodized, and has a rectangular shape when viewed in a plan view. The substrate G to be processed mounted on the mounting table 13 is attracted and held by an electrostatic chuck (not shown). The mounting table 13 is housed in the insulator frame 14, and is installed on the bottom surface of the container body 10 via the insulator frame 14.

A second high frequency power supply 152 is connected to the mounting table 13 via a matching unit 151. The second high frequency power supply 152 applies high frequency power for bias, for example, high frequency power having a frequency of 3.2 MHz to the mounting table 13. By the self-bias generated by the high frequency power for the bias, the ions in the plasma generated in the processing space 100 can be drawn into the substrate G to be processed.
In the mounting table 13, in order to control the temperature of the substrate G to be processed, a temperature control mechanism including a heating means such as a ceramic heater and a refrigerant flow path, a temperature sensor, and a back surface of the substrate G to be processed A gas flow path for supplying He gas for heat transfer is provided (neither is shown).

An exhaust port 103 is formed on the bottom surface of the container body 10, and a vacuum exhaust unit 12 including a vacuum pump or the like is connected to the exhaust port 103. The inside of the processing space 100 is evacuated to the pressure at the time of plasma processing by the vacuum exhaust unit 12. As shown in FIG. 3, a plurality of exhaust ports 103 are provided around the mounting table 13, and are located near the four corners of the rectangular mounting table 13 when viewed in a plan view, or at positions along the four sides of the mounting table 13. Have been placed.

As shown in FIG. 3 and FIG. 4, which is a plan view of the metal window 3 viewed from the processing space 100 side, a rectangular frame made of metal such as aluminum is formed on the upper surface side of the side wall of the container body 10. A metal frame 11 is provided. A sealing member 110 for keeping the processing space 100 airtight is provided between the container body 10 and the metal frame 11. Here, the container body 10 and the metal frame 11 constitute the processing container of the present embodiment.

Further, the metal window 3 of this example is divided into a plurality of partial windows 30, and these partial windows 30 are arranged inside the metal frame 11 to form a rectangular metal window 3 as a whole. Each partial window 30 is made of, for example, a non-magnetic and conductive metal, aluminum, or an alloy containing aluminum.

Each partial window 30 also serves as a gas shower head portion 30a to 30d for supplying processing gas. For example, as shown in FIG. 3, a gas diffusion chamber 301 for diffusing the etching gas is formed inside each of the gas shower head portions 30a to 30d. Further, on the lower surface side of the region where the gas diffusion chamber 301 is formed, a large number of gas discharge holes 302 for supplying the processing gas to the processing space 100 are formed.
The partial windows 30 (gas shower head portions 30a to 30d) having these configurations are held via holding portions (not shown) to form the metal window 3 described above and also to form the ceiling surface of the processing space 100. is doing.

Explaining the planar shape and arrangement of the gas shower head portions 30a to 30d with reference to FIG. 4, the gas shower head portions 30a to 30d are the metal windows 3 which are ceiling surfaces from the central portion side to the peripheral portion side. Is provided in a plurality of regions divided into three in the radial direction.
The gas shower head portion 30a is provided in the rectangular region on the central portion side of the three-divided regions, and the gas shower head portion 30b is provided in the angular annular region around the gas shower head portion 30a. It is provided.

Further, among the plurality of regions formed by dividing the ceiling surface, the angular annular region on the most peripheral portion side is adjacent to the four regions including the corner portion of the angular ring (corner portion of the rectangular ceiling surface). It is divided into four regions including the sides of the square ring (rectangular shape) sandwiched between the matching corners. The peripheral gas shower head portion 30d is provided in the four regions including the corner portion, and the peripheral gas shower head portion 30c is provided in the four regions including the side portion.

Here, in order to perform vacuum exhaust in the processing space 100, a plurality of the above-mentioned exhaust ports 103 arranged around the mounting table 13 are below the annular region provided with the peripheral gas shower head portions 30c and 30d. It is provided at a position or a position on the outer side of the lower position (FIG. 3).

The gas shower head portions 30a to 30d (partial windows 30) that are separated from each other are electrically insulated from the metal frame 11 and the container body 10 on the lower side thereof by the insulating member 31, and the adjacent gas shower head portions 30a to 30a. The 30ds are also insulated from each other by the insulating member 31 (see FIGS. 3 and 4).

Further, in order to improve the plasma resistance of the partial window 30, the surface of each partial window 30 on the processing space 100 side (the lower surface of the gas shower head portions 30a to 30d) is plasma resistant coated. Specific examples of the plasma resistant coating include the formation of a dielectric film by anodizing and ceramic spraying.

As shown in FIG. 3, the gas diffusion chambers 301 of the gas shower head portions 30a to 30d are connected to the CF ₄ gas supply unit 4a and the _O2 gas supply unit 4b via the gas supply pipes 43a to 43d.
The CF ₄ gas supply unit 4a corresponds to the first processed gas raw material supply unit of the present embodiment (indicated as “first processed gas raw material supply unit” in FIGS. 3 and 5). The CF ₄ gas, which is the first raw material for the processing gas, is supplied from the CF ₄ gas supply unit 4a. Of course, the NF ₃ gas supply unit may be provided in place of the CF ₄ gas supply unit 4a to supply the NF ₃ gas as the first processing gas raw material.

On the downstream side of the CF ₄ gas supply unit 4a, a first supply flow rate adjusting unit 41a for adjusting the flow rate of the CF ₄ gas supplied to the processing space 100 is provided, and further, a first supply flow rate adjusting unit 41a. On the downstream side of the above, a plurality of, for example, four first distribution flow paths 401 are connected via an on-off valve V1. Each of the first distribution flow paths 401 is connected to the gas supply pipes 43a to 43d on the gas shower head portions 30a to 30d side, and a plurality of CF ₄ gases whose flow rate is adjusted by the first supply flow rate adjusting portion 41a are used. It serves to distribute and supply to the gas shower head portions 30a to 30d. For example, the first supply flow rate adjusting unit 41a is configured by a mass flow controller (MFC).

Further, each of the first distribution flow paths 401 is provided with first distribution flow rate adjusting units 421a to 424a for adjusting the flow rate of the CF ₄ gas supplied to the respective gas shower head units 30a to 30d. .. For example, the first distribution flow rate adjusting units 421a to 424a are configured by MFC.
Since the CF ₄ gas whose flow rate has been adjusted by the first supply flow rate adjusting unit 41a on the upstream side is distributed to an arbitrary flow rate ratio by the first distribution flow rate adjusting units 421a to 424a on the downstream side, the first supply flow rate When the flow rate set value of CF ₄ gas in the adjusting unit 41a is F ₁ and the flow rate setting values of the first distributed flow rate adjusting units 421a to 424a are f ₁₁ to f ₁₄ , F ₁ = f ₁₁ + f ₁₂ + f ₁₃ + f. ₁₄ relationships hold.

On-off valves V31 to V34 are provided on the downstream side of each of the first distribution flow rate adjusting units 421a to 424a, and the first distribution flow path 401 is a gas supply pipe 43a at a position on the downstream side of these on-off valves V31 to V34. It is connected to ~ 43d.
At this time, by unifying the length and cross-sectional area of the gas flow path from each of the first distribution flow rate adjusting units 421a to 424a to the plurality of gas shower head units 30a to 30d and making the conductance of the gas flow path equal, a plurality of. Gas can be supplied more evenly from the gas shower head portions 30a to 30d of the above.

On the other hand, the O ₂ gas supply unit 4b corresponds to the second processed gas raw material supply unit of the present embodiment (in FIGS. 3 and 5, it is indicated as "second processed gas raw material supply unit". ), O 2 gas, which is a _second processing gas raw material, is supplied from the O ₂ gas supply unit 4b.
On the downstream side of the O ₂ gas supply unit 4b, a second supply flow rate adjusting unit 41b for adjusting the flow rate of the O ₂ gas supplied to the processing space 100 is provided, and further, a second supply flow rate adjusting unit 41b. On the downstream side of the above, a plurality of, for example, a first distribution flow path 401 and four second distribution flow paths 402 are connected via an on-off valve V2. Each of the second distribution channels 402 joins the first distribution channels 401 that are different from each other, and the gas supply pipes 43a on the gas shower head portions 30a to 30d side pass through the first distribution channels 401. It is connected to ~ 43d. Each of the second distribution flow paths 402 also plays a role of distributing and supplying the O ₂ gas whose flow rate is adjusted by the second supply flow rate adjusting unit 41b to the plurality of gas shower head units 30a to 30d. For example, the second supply flow rate adjusting unit 41b is configured by MFC.

Further, each of the second distribution flow paths 402 is provided with second distribution flow rate adjusting units 421b to 424b for adjusting the flow rate of the O ₂ gas supplied to the respective gas shower head units 30a to 30d. .. For example, the second distribution flow rate adjusting units 421b to 424b are configured by MFC.
Since the O ₂ gas whose flow rate has been adjusted by the second supply flow rate adjusting unit 41b on the upstream side is distributed to an arbitrary flow rate ratio by the second distribution flow rate adjusting units 421b to 424b on the downstream side, the second supply flow rate When the flow rate setting value of the O ₂ gas in the adjusting unit 41b is F2 and the flow rate setting values of the _second distribution flow rate adjusting units 421b to 424b are f ₂₁ to f ₂₄ , F ₂ = f ₂₁ + f ₂₂ + f ₂₃ + f. _Twenty -four relationships hold.

On-off valves V41 to V44 are provided on the downstream side of each of the second distribution flow rate adjusting units 421b to 424b, and each of the second distribution flow paths 402 supplies gas at positions on the downstream side of these on-off valves V41 to V44. It joins the first distribution flow path 401 connected to the pipes 43a to 43d.
At this time, by unifying the length and cross-sectional area of the gas flow path from each of the second distribution flow rate adjusting units 421b to 424b to the plurality of gas shower head units 30a to 30d and making the conductance of the gas flow path equal, a plurality of. Gas can be supplied more evenly from the gas shower head portions 30a to 30d of the above.

FIG. 5 shows the first and second distribution flow paths provided with the gas shower head portions 30a to 30d constituting the metal window 3 and the first and second distribution flow rate adjusting portions 421a to 424a and 421b to 424b. The connection relationship with 401 and 402 is shown.
According to FIG. 5, with respect to the gas shower head portion 30a on the central portion side and the gas shower head portion 30b around it, the first distributed flow rate adjusting unit 421a, 422a and the second distributed flow rate adjusting unit 421b, 422b. Adjusts the flow rate of each gas.

On the other hand, for the four peripheral gas shower head portions 30c constituting the side portion of the angular ring on the peripheral portion side, the gas whose flow rate is adjusted by using the common first and second distribution flow rate adjusting units 423a and 423b. Is distributed and supplied. Further, the flow rate of the four peripheral gas shower head portions 30d constituting the corner portion of the angular ring is adjusted by using the common first and second distribution flow rate adjusting portions 424a and 424b different from those on the side portion side. Gas is distributed and supplied.

Further, as shown in FIG. 3, a top plate portion 61 is arranged on the upper side of the metal window 3, and the top plate portion 61 is supported by a side wall portion 63 provided on the metal frame 11. The space surrounded by the metal window 3, the side wall portion 63, and the top plate portion 61 constitutes the antenna chamber 50, and the high frequency antenna 5 is arranged inside the antenna chamber 50 so as to face the partial window 30. ..

The high frequency antenna 5 is arranged apart from the partial window 30 via, for example, a spacer made of an insulating member (not shown). The high-frequency antenna 5 is formed in a spiral shape so as to orbit along the circumferential direction of the rectangular metal window 3 in the plane corresponding to each partial window 30 (planar illustration omitted). The shape of the high-frequency antenna 5 is not limited to a spiral, and may be an annular antenna in which one or a plurality of antenna wires are annular. Further, a multiple antenna may be adopted in which a plurality of antenna wires are wound while shifting the angle so that the whole is spiral. As described above, the structure of the high-frequency antenna 5 does not matter as long as the antenna wire is provided so as to circulate along the circumferential direction in the plane corresponding to the metal window 3 and each partial window 30.

A first high frequency power supply 512 is connected to each high frequency antenna 5 via a matching unit 511. High-frequency power of, for example, 13.56 MHz is supplied to each high-frequency antenna 5 from the first high-frequency power supply 512 via the matching unit 511. As a result, an eddy current is induced on the surface of each of the partial windows 30 during the plasma processing, and an induced electric field is formed inside the processing space 100 by this eddy current. The processing gas discharged from the gas discharge hole 302 is turned into plasma inside the processing space 100 by an induced electric field.

Further, as shown in FIG. 3, the plasma processing apparatus 1 is provided with a control unit 6. The control unit 6 is composed of a computer including a CPU (Central Processing Unit) (not shown) and a storage unit. In this storage unit, the inside of the processing space 100 in which the substrate G to be processed is arranged is vacuum exhausted, and the high frequency antenna 5 is provided. For outputting a control signal for executing an operation of processing the substrate G to be processed by converting the etching gas (processed gas) into plasma and a flow rate set value of each flow rate adjusting unit 41a, 41b, 421a to 424a, 421b to 424b. A program in which a group of steps (instructions) is assembled is recorded. This program is stored in a storage medium such as a hard disk, a compact disk, a magnetic optical disk, or a memory card, and is installed in the storage unit from there.

The operation of the plasma processing apparatus 1 having the configuration described above will be described.
First, the gate valve 102 is opened, and the substrate G to be processed is carried into the processing space 100 from the adjacent vacuum transfer chamber by a transfer mechanism (neither is shown) via the carry-in outlet 101. Next, the substrate G to be processed is placed on the mounting table 13 and fixed by an electrostatic chuck (not shown), while the transport mechanism is retracted from the processing space 100 and the gate valve 102 is closed.

After that, the on-off valves V1, V2, V31 to V34, and V41 to V44 are opened, and the flow rates of the CF ₄ gas and O ₂ are adjusted by the first supply flow rate adjusting unit 41a and the second supply flow rate adjusting unit 41b, respectively. Start supplying gas.
The O ₂ gas is divided into four second distribution flow paths 402, and after the flow rate is adjusted by the second distribution flow rate adjusting units 421b to 424b, the O 2 gas joins the first distribution flow path 401. On the other hand, the CF ₄ gas was diverted into the four first distribution flow paths 401, the flow rate was adjusted by the first distribution flow rate adjusting units 421a to 424a, and then the gas was supplied from the second distribution flow path 402 side. It is mixed with O ₂ gas.

For each of the CF ₄ gas and the O ₂ gas, the first supply flow rate adjusting unit 41a, the second supply flow rate adjusting unit 41b, the first distributed flow rate adjusting unit 421a to 424a, and the second distributed flow rate adjusting unit 421b to With the 424b, the first and second treated gas raw materials obtained from the first and second treated gas raw material supply units are independent of each other with a relatively simple configuration by performing two-step flow rate adjustment before and after the diversion. It can be mixed at an arbitrary ratio and supplied to each position of the substrate to be processed. As a result, it becomes possible to perform the etching process at the flow rate ratio of O ₂ gas / CF ₄ gas corresponding to the inclination of the end portion of the photoresist film 704 for each area of the glass substrate 701.
The etching gas obtained by mixing the CF ₄ gas and the O ₂ gas is introduced into the gas diffusion chambers 301 of the gas shower head portions 30a to 30d via the gas supply pipes 43a to 43d.

Regarding the flow rate ratio of O ₂ gas / CF ₄ gas, the etching gas distributed to the gas shower head portion 30a has a value in the range of O ₂ gas / CF ₄ gas = 1: 3 to 3: 2, and peripheral gas. The etching gas distributed to the shower head portions 30c and 30d is adjusted to a value within the range of O ₂ gas / CF ₄ gas = 1: 3 to 3: 2. The flow rate ratio of the O ₂ gas / CF ₄ gas with respect to the etching gas distributed to the gas shower head portion 30b located between the gas shower head portion 30a and the peripheral gas shower head portions 30c and 30d is described above. It is adjusted to a value within each range.
Further, as will be described later, the peripheral gas shower head portion 30c at the side portion and the peripheral gas shower head portion 30d at the corner portion may supply etching gas having different flow ratios of O ₂ gas / CF ₄ gas. ..

On the other hand, on the container body 10 side, vacuum exhaust is performed in the processing space 100 from the vacuum exhaust unit 12, and the pressure atmosphere in the processing space 100 is adjusted to, for example, about 0.66 to 26.6 Pa. Further, the temperature of the substrate G to be processed mounted on the mounting table 13 is adjusted, and He gas for heat transfer is supplied to the back surface side of the substrate G to be processed.

Next, high-frequency power is applied from the first high-frequency power source 512 to the high-frequency antenna 5, thereby generating a uniform induced electric field in the processing space 100 through the metal window 3. As a result, the etching gas is turned into plasma in the processing space 100 by the induced electric field, and a high-density inductively coupled plasma is generated. Then, the ions in the plasma are drawn toward the substrate G to be processed by the high-frequency power for bias applied from the second high-frequency power source 152 to the mounting table 13, and the etching process of the substrate G to be processed is performed.

At this time, the first and second distribution flow rate adjusting portions 421a to 424a and 421b to 424b are located on the peripheral portion side of the metal window 3 which is the ceiling surface, on the central portion side of the peripheral gas shower head portions 30c and 30d. The flow rates of CF ₄ gas and O ₂ gas are set, respectively, so that the concentration of O ₂ gas in the etching gas supplied from the gas shower head portions 30b and 30a located in is high.
In other words, the first and second distribution flow control units 421a to 424a and 421b to 424b have a taper at the end of the photoresist film 704 patterned on the upper surface side of the SiO film 702 and the SiN film 703 (etching target film). Depending on the region where the size of the angle is different, the etching gas is supplied to the region where the taper angle is smaller than the gas shower head portions 30c and 30d at the position where the etching gas is supplied to the region where the taper angle is large. The flow rates of CF ₄ gas and O ₂ gas are set so that the oxygen concentration in the etching gas supplied from the gas shower head portions 30b and 30a at the position where the gas shower head is located is high, respectively.

In the region on the peripheral portion side of the substrate G to be processed in which the photoresist film 704 having a large taper angle at the end is patterned by the flow rate setting of the CF ₄ gas and the O ₂ gas described above (FIG. 1 (a)), O ₂ It is possible to perform an etching process using an etching gas having a low gas concentration. As a result, the SiO film 702 and the SiN film 703 of the glass substrate 701 can be removed by etching in good condition (FIG. 1 (b)).

At this time, the peripheral gas shower head portion 30c on the peripheral portion side and the peripheral gas shower head portion 30d on the corner portion are connected to the first and second distribution flow rate adjusting portions 423a, 424a, 423b, 424b, which are different from each other. Therefore, it is possible to make the concentration of the O ₂ gas in the etching gas supplied to the peripheral gas shower head portions 30c and 30d different.

On the other hand, in the region on the central portion side of the substrate G to be processed (FIG. 2A), where the photoresist film 704 having a small taper angle at the end is patterned, an etching gas having a high concentration of O ₂ gas is used. It is possible to perform etching processing. As a result, the SiO film 702 and the SiN film 703 can be removed by etching from the glass substrate 701 in good condition (FIG. 2 (c)).

Then, after plasma processing is performed for a preset time, power is supplied from the high-frequency power supplies 512 and 152, and CF _{4 gas and O 2 gas are supplied from the CF 4 gas supply} unit 4a and the O ₂ gas supply unit 4b. At the same time as stopping, exhaust treatment is performed from within the treatment space 100. After that, the substrate G to be processed is carried out in the order opposite to that at the time of carrying in.

According to the plasma processing apparatus 1 according to the present embodiment, the following effects are obtained. The CF ₄ gas supply unit 4a and the O ₂ gas supply unit 4b are provided with first and second supply flow rate adjustment units 41a and 41b for adjusting the flow rates of the CF ₄ gas and the O ₂ gas, respectively, and a plurality of gases are further provided. The first and second distribution flow rate adjustments for the plurality of first and second distribution channels 401 and 402 that distribute these CF ₄ gas and O ₂ gas to the shower head portions 30a to 30d, respectively. Parts 421a to 424a and 421b to 424b are provided. As a result, the CF ₄ gas and O ₂ gas obtained from the common CF ₄ gas supply unit 4a and O ₂ gas supply unit 4b can be mixed at an arbitrary ratio, and these gases are mixed at a desired ratio. The etched etching gas can be supplied to each position of the substrate G to be processed. As a result, even if the longitudinal cross-sectional shape of the photoresist film 704 patterned according to the position of the substrate G to be treated in the surface to be treated differs, the vertical cross-sectional shape corresponds to each of the plurality of gas shower head portions 30a to 30d. Since CF ₄ gas and O ₂ gas can be supplied at the same flow rate ratio, good etching treatment results can be obtained.

Here, the above-mentioned plasma processing apparatus 1 configured to be able to supply etching gases having different O ₂ concentrations from a plurality of gas shower head portions 30a to 30d is the taper residue described with reference to FIGS. 1 and 2. When applied to an etching process for removing the etching target film (SiO film 702 or SiN film 703, which is a silicon-containing film in the above example) in a good condition in a process in which the residue of 71a or the etching residue 71b is a problem. Not limited.
For example, when the above-mentioned inclination formed at the end of the photoresist film 704 is transferred to the pattern after etching processing, the plasma processing apparatus 1 is used for the purpose of aligning the taper angle of the transferred inclination. You can also do it.

6 (a) and 7 (a) show an example in which a photoresist film 704 is patterned on the upper surface of an etching target film 707 which is a polycrystalline silicon or molybdenum in a substrate G to be processed in which a thin film transistor is formed. (The description on the lower layer side of the etching target film 707 is omitted).

The etching target film 707, which is a polycrystalline silicon film or a molybdenum film, is a first processing gas such as carbon tetrafluoride (CF ₄ ) gas, sulfur hexafluoride (SF ₆ ) gas, and nitrogen trifluoride (NF ₃ ). It can be removed by using an etching gas obtained by plasma-forming a gas containing at least one selected gas from a gas or a chlorine (Cl ₂ ) gas and an oxygen (O ₂ ) gas as a second processing gas. ..
In this example, similarly to the removal of the silicon-containing film (SiO film 702 and SiN film 703) described above, the case where the etching target film 707 is removed by using an etching gas containing CF ₄ gas and O ₂ gas. explain.

Here, the taper angle of the photoresist film 704 may be affected by the coating and developing processes of the photoresist film 704, which is opposite to the examples shown in FIGS. 1 (a) and 1 (a) depending on the process. In addition, the taper angle may be large on the central portion side of the substrate G to be processed, and the taper angle may be small on the peripheral portion side. 6 (a) and 7 (a) show such an example.

With respect to the substrate G to be treated on which the photoresist film 704 having a different taper angle is formed in this way, for example, the mixing ratio (O ₂ gas concentration) of CF ₄ gas / O ₂ gas is set on the entire surface of the substrate G to be treated. Consider the case where the same etching gas is supplied and the etching process is performed.
In the etching process using the photoresist film 704, the etching of the etching target film 707 proceeds while the photoresist film 704 is gradually ashed by the action of the O ₂ gas contained in the etching gas. Therefore, by controlling the concentration of the O ₂ gas contained in the etching gas, the ashing rate of the photoresist film 704 during etching of the etching target film 707 can be changed.

At this time, if the concentrations of the O ₂ gas in the etching gas are substantially equal between the central portion side and the peripheral portion side of the substrate G to be processed, the ashing amount per unit time of the photoresist film 704 at each position is substantially the same. Etching proceeds under the conditions.
As a result, since etching is performed with the taper angle of the photoresist film 704 being different, the taper angle transferred to the pattern 707a is also different in the plane of the substrate G to be processed. That is, the taper angle θ ₁ of the end portion of the pattern 707a formed on the central portion side of the substrate G to be processed becomes larger than the taper angle θ ₂ of the end portion of the pattern 707a formed on the peripheral portion side. (FIGS. 6 (b) and 7 (b)).

On the other hand, there may be a need to make the taper angles of the polycrystalline silicon or molybdenum pattern 707a as uniform as possible in the plane of the substrate G to be processed due to a request from the subsequent treatment following the etching treatment. The plasma processing apparatus 1 described with reference to FIG. 3 can be utilized even in such a case.
In this case, each of the first distribution flow rate adjusting units 421a to 424a sets the flow rate of the CF ₄ gas so that the etching process is completed within a predetermined processing time. Further, the second distribution flow rate adjusting portions 421b to 424b are gas shower head portions 30b located on the central portion side of the peripheral gas shower head portions 30c and 30d located on the peripheral portion side of the metal window 3 which is the ceiling surface. The flow rate of the O ₂ gas is set so that the concentration of the O ₂ gas in the etching gas supplied from the 30a is high.

In other words, the first and second distribution flow control units 421a to 424a and 421b to 424b are etched with respect to the region where the taper angle of the end portion of the photoresist film 704 patterned on the upper surface side of the etching target film 707 is small. The oxygen concentration in the etching gas supplied from the gas shower heads 30b and 30a at the position where the etching gas is supplied to the region having a larger taper angle than the gas shower heads 30c and 30d at the position where the gas is supplied is The flow rates of CF ₄ gas and O ₂ gas are set so as to be high, respectively.

In the region on the central portion side of the substrate G to be processed in which the photoresist film 704 having a large taper angle is patterned by the flow rate setting of the CF ₄ gas and the O ₂ gas described above (FIG. 6A), the O ₂ gas In the region on the peripheral edge side of the substrate G to be treated, in which the etching process is performed using a high-concentration etching gas and the photoresist film 704 having a small taper angle is patterned (FIG. 7 (a)), the O ₂ gas The etching process is performed using an etching gas having a low concentration.

At this time, since the ashing speed of the photoresist film 704 having a large taper angle is higher than that of the photoresist film 704 having a small taper angle, ashing proceeds in a direction in which the difference in the taper angle of each region is alleviated. As a result, etching can be performed while the taper angles _θ'1 and _θ'2 at the ends of the pattern 707a formed by using these photoresist films 704 are brought close to each other (FIGS. 6 (c) and 7 (FIG. 7). c)).

Next, the configuration and application process of the plasma processing apparatus 1a according to the second embodiment will be described with reference to FIGS. 8 and 9.
FIG. 8A shows an enlarged vertical sectional side view of the upper surface of the substrate G to be processed. In the substrate G to be processed, an aluminum film 705 having a thickness of about several hundred nm is formed on the glass substrate 701, and a SiO ₂ film 706 having a thickness of about several tens nm is formed on the upper surface thereof.

A photoresist film 704a for etching the laminated film of the aluminum film 705 and the SiO ₂ film 706 in a line-and-space manner is patterned on the upper surface of the SiO ₂ film 706. The photoresist film 704a is patterned so that the line-and-space line width and the space width are each about several tens of nm.

Chlorine (Cl ₂ ) gas, which is a first processing gas raw material and a main etching gas, and nitrogen (a second processing gas raw material, which is also an additive gas), which are the first processing gas raw materials and the main etching gas, with respect to the substrate G having the above configuration. N ₂ ) By supplying a gas containing, for example, fluoroform (CHF ₃ ) as an additive gas (hereinafter, also referred to as “halogen-containing additive gas”) which is a gas and a halogen-containing gas, as a plasma, by the photoresist film 704a. An etching process is performed to remove the aluminum film 705 and the SiO ₂ film 706 in the uncovered region. Here, an example in which fluoroform (CHF ₃ ) is used as the halogen-containing additive gas is shown, but CF ₄ , C ₂ HF ₅ , C ₄ F ₈ , BCl ₃ , HCl and the like can be used as the halogen-containing additive gas. ..

Regarding the substrate G to be processed, the present inventors have a region where the etching process is easy to be performed and a desired line and space pattern by the etching process, depending on the position of the substrate G to be processed in the surface to be processed. It was found that there is a region where 72 is difficult to obtain.

For example, as shown in FIG. 8B, a relatively good line and space pattern 72 is formed on the peripheral side of the substrate G to be processed, while FIG. 8 is formed on the central side of the substrate G to be processed. As shown in (c), an incomplete pattern 73 was formed due to poor etching.
The reason why the incomplete pattern 73 is formed on the central portion side of the substrate G to be processed is the amount of carbon generated by etching the photoresist film 704a as compared with the peripheral portion side of the substrate G to be processed. In addition, since the exhaust capacity of the generated carbon is low, these carbons adhere to the aluminum film 705 and the SiO ₂ film 706 that are not covered by the photoresist film 704a, and the Cl ₂ gas which is the main etching gas. It is expected that this may be due to the suppression of the etching process.

Therefore, the plasma processing apparatus 1a according to the second embodiment can supply etching gas having a different flow rate to each region of the substrate G to be processed by using the gas shower head portions 30a to 30d divided into a plurality of portions. It has a possible configuration.
FIG. 9 shows the Cl ₂ gas supply unit 4c (indicated as “first processing gas raw material supply unit” in FIG. 9), which is the first processing gas raw material supply unit, and the second processing gas raw material. The N ₂ gas supply unit 4d and the halogen-containing additive gas supply unit 4e, which are supply units (in FIG. 9, "second processing gas raw material supply unit (1) and second processing gas raw material supply unit (2), respectively). ], The supply path of each gas to each gas shower head portion 30a to 30d is schematically shown. Since the specific device configuration of the plasma processing device 1a is the same as that of the plasma processing device 1 described with reference to FIGS. 3 and 4, the description thereof will be omitted again. Further, in the plasma processing apparatus 1a shown in FIG. 9 and the plasma processing apparatus 1b shown in FIG. 10 described later, the components common to those described with reference to FIGS. 3 and 4 are used in these figures. It has the same code as the one that was there.

In the plasma processing apparatus 1a shown in FIG. 9, the gas types of the first and second processing gas raw materials are different, and two types of gas supplied from the _N2 gas supply unit 4d and the halogen-containing additive gas supply unit 4e are used. The point that the gas is mixed and then split in the second distribution flow path 402 is different from the plasma processing apparatus 1 according to the first embodiment described above. Further, in this example, the flow rate ratio of the N ₂ gas / halogen-containing added gas is the same between the gas shower head portions 30a to 30d, while the distribution ratio of Cl ₂ gas from each gas shower head portion 30a to 30d is different. The flow rate is adjusted by the first and second distribution flow rate adjusting units 421a to 424a and 421b to 424b so that the gas can be adjusted.

According to the plasma processing apparatus 1a provided with the above configuration, the gas shower head portion 30a located on the central portion side of the substrate G to be treated to which carbon caused by the photoresist film 704a easily adheres during etching is located on the peripheral portion side. Peripheral gas The distribution ratio of the additive gas N ₂ gas and the halogen-containing additive gas to the Cl ₂ gas, which is the main etching gas, is smaller than that of the peripheral gas shower head portions 30c and 30d, which is caused by the photoresist film 704a. It is possible to suppress the adhesion of carbon and obtain a good line and space pattern 72.
Further, it is also possible to make the supply flow rates of the main etching gas, which is the first processing gas raw material, and the added gas, which is the second processing gas raw material, different between the peripheral gas shower head portions 30c and 30d divided in the circumferential direction. be.

In the plasma processing devices 1 and 1a according to the first and second embodiments described with reference to FIGS. 3, 4, and 7, the peripheral gas shower head portion 30c located in the outermost angular annular region. An example of dividing the peripheral gas shower head portion 30d in the circumferential direction has been shown, but the peripheral gas shower head portion 30c and the peripheral gas shower head portion 30d divided in the circumferential direction are not limited to the outermost region.

The partial window 30 which is a ceiling surface may be divided into four in the radial direction, and each annular region one inside the outermost circumference may be divided in the circumferential direction to arrange the peripheral gas shower head portions 30c and 30d.
For example, if the area is located on the outer peripheral side of the distance from the center position to the peripheral position of the partial window 30, the peripheral gas shower head portions 30c and 30d divided in the circumferential direction are provided to exhaust the gas. It is possible to improve the processing result by adjusting the flow rate ratio of the etching gas (processing gas) and adjusting the supply flow rate according to the positional relationship with the port 103.

On the other hand, it is not essential to divide the partial window 30 in the circumferential direction located on the outer peripheral side. As shown in the plasma processing apparatus 1b of FIG. 10, the gas shower head portion 30e arranged in the region on the outer peripheral side formed by dividing the rectangular partial window 30 in the radial direction is divided in the circumferential direction. Instead, the processing gas may be supplied from the angular annular gas shower head portion 30e.

FIG. 10 shows silicon tetrafluoride (SiF ₄ ) gas and silicon tetrafluoride (SiCl ₄ ) gas, which are the raw materials for the first processing gas, and nitrogen (N ₂ ) gas or oxygen (O), which are the raw materials for the second processing gas. ₂ ) A configuration example of a plasma processing apparatus 1b that performs a film-forming process of a SiO ₂ film or a SiN film on a substrate G to be processed by supplying a film-forming gas containing a gas into plasma is shown.

FIG. 10 shows the SiC ₄ gas supply unit 4f and the SiC ₄ gas supply unit 4h as the first processing gas raw material supply unit (in FIG. 10, the “first processing gas raw material supply unit (1) and the first” are shown, respectively. (Indicated as "processed gas raw material supply unit (2)") is provided, and an example is provided in which an N ₂ gas supply unit 4 g and an O ₂ gas supply unit 4i are provided as a second processed gas raw material supply unit. (In FIG. 10, they are displayed as "second processed gas raw material supply unit (1) and second processed gas raw material supply unit (2)", respectively). First supply flow rate adjusting units 41a and 41c are provided on the downstream sides of the _SiC4 gas supply unit 4f and the SiC4 gas supply unit _4h , respectively, and further downstream of the first supply flow rate adjusting units 41a and 41c. Is connected in common to three first distribution flow paths 401 via open / close valves V1 and V3. Further, on the downstream side of the N ₂ gas supply unit 4g and the O ₂ gas supply unit 4i, first supply flow rate adjustment units 41b and 41d are provided, respectively, and further downstream of the first supply flow rate adjustment units 41b and 41d. On the side, three second distribution flow paths 402 are commonly connected via open / close valves V2 and V4.

In the plasma processing apparatus 1b shown in FIG. 10, two types of gases supplied from the SiCl ₄ gas supply unit 4f and the SiC4 gas supply unit _4h are mixed and then diverted in the first distribution flow path 401. In the first embodiment described above, the gas supplied from either the N ₂ gas supply unit 4g or the O ₂ gas supply unit 4i is diverted in the second distribution flow path 402. It is different from the plasma processing apparatus 1. By switching between N ₂ gas and O ₂ gas from either the N ₂ gas supply unit 4 g or the O ₂ gas supply unit 4i, the SiN film or the SiO ₂ film can be switched to form a film. ..
Since the specific device configuration of the plasma processing device 1b is the same as that of the plasma processing device 1 described with reference to FIGS. 3 and 4, the description thereof will be omitted again.

FIG. 11 shows the pressure at each position in the path from the gas box provided with the SiCl ₄ gas supply unit 4f, the SiC ₄ gas supply unit 4h, and the _N2 gas supply unit 4g to the gas shower head units 30a, 30b, and 30e. Is shown.
In the square plot in FIG. 11, the SiC ₄ gas supply unit 4f, the SiF ₄ gas supply unit 4h, and N are located upstream of the first distribution flow rate adjusting units 421a to 423a without providing the second distribution flow path 402. ₂ gas supply unit 4g is provided, and for example, _SiC4 gas whose flow rate is adjusted to 150sccm, _SiCl4 gas whose flow rate is adjusted to 150sccm, and _N2 gas whose flow rate is adjusted to 4000sccm are mixed, and the first distribution flow path is used. The pressure at each position when the gas is supplied to the gas shower head portions 30a, 30b, and 30e via the 401 is shown.

When SiCl ₄ gas, SiC ₄ gas, and N ₂ gas are mixed in advance, the total pressure in the path on the upstream side of the first distribution flow rate adjusting units 421a to 423a, which are MFCs, increases by about 33 kPa (250 torr). According to the vapor pressure curve of SiCl ₄ (boiling point 57.6 ° C.) shown in FIG. 12, the pressure is the vapor pressure at a temperature higher than 25 ° C. Therefore, if the piping on the upstream side of the first distribution flow rate adjusting units 421a to 423a through which the mixed gas (deposited gas) of SiCl ₄ gas, SiC ₄ gas and N ₂ gas flows is not heated, SiCl ₄ will condense. There is a risk that it will end up.

Further, since the first distribution flow rate adjusting units 421a to 423a have low conductance and the pressure of the mixed gas is high upstream of the first distribution flow rate adjusting units 421a to 423a, the SiCl ₄ gas having a low vapor pressure is correctly supplied. There is also the problem that it is difficult.

Therefore, as shown in FIG. 10, from the first distribution flow path 401 for the SiCl ₄ gas and the SiC ₄ gas supplied from the SiCl ₄ gas supply unit 4f and the SiC4 gas supply unit _4h , and the _N2 gas supply unit 4g. By separating from the second distribution flow path 402 for supplying N ₂ gas to be supplied, as shown in the diamond plot in FIG. 11, the path on the upstream side of the first distribution flow rate adjusting unit 421a to 423a. It is possible to reduce the total pressure inside, suppress the condensation of the SiCl ₄ gas having a low vapor pressure, and supply the SiCl ₄ gas correctly.
Further, the O ₂ gas is supplied from the O ₂ gas supply unit 4i by switching from the supply of the N ₂ gas from the N ₂ gas supply unit 4 g, and the mixed gas of the SiCl ₄ gas, the SiC ₄ gas and the O ₂ gas is produced. Similar effects can be obtained even when a film is formed using a film gas).

Further, when the SiC ₄ gas or the SiC ₄ gas is independently supplied from the SiC ₄ gas supply unit 4f or the SiC ₄ gas supply unit 4h, the substances constituting each gas are condensed or it is difficult to supply them correctly. If there is a problem, the first distribution channel 401 for the SiCl ₄ gas or the SiC ₄ gas and the second distribution channel 402 for supplying the N ₂ gas or the O ₂ gas may be separated. As a result, condensation of each substance can be suppressed, and _SiCl4 gas or _SiC4 gas can be correctly supplied.

In the example described above, an example using _SiCl4 gas and _SiC4 gas as an example of the first processing gas raw material is shown. Here, when the first treated gas raw material is used as a raw material for Si, the gas types that can be adopted include the gas types of SiBr ₄ , SiF ₂ Cl ₂ , and SiH ₄ in addition to the above-mentioned SiCl ₄ and _SiC4 . Any one gas type selected, or a combination of two or more gas types can also be used.
Further, in the above-mentioned example, an example using N ₂ gas and O ₂ gas as an example of the second processing gas raw material is shown. Here, when the second processing gas raw material is used as an oxidation gas, a nitride gas, a diluting gas, and a cleaning gas, the gas types that can be adopted include O ₂ , N ₂ , N ₂ O, Ar, He, and NF ₃ . Any one gas type selected from the gas type group, or a combination of two or more gas types can also be used.

Like the plasma processing apparatus 1b described above, the SiC ₄ gas supply unit 4f and the SiC ₄ gas supply unit 4h (first processing gas raw material) due to the need on the upstream side of the gas shower head units 30a, 30b, 30e. When separating the N ₂ gas supply unit 4g and the O ₂ gas supply unit 4i (second processing gas raw material supply unit), the gas shower head unit 30e on the outer peripheral side may be divided in the circumferential direction. Not necessary.
However, from the viewpoint of adjusting the film thickness, the supply flow rate of the film-forming gas and the flow rate ratio of the first and second treated gas raw materials are set for each region divided in the circumferential direction such as the corners and sides of the substrate G to be treated. Of course, when it is necessary to change the size, the film-forming gas may be supplied by using the peripheral gas shower head portions 30c and 30d divided in the circumferential direction.

In the plasma processing devices 1, 1a, 1b according to the embodiment described with reference to FIGS. 3, 4, 7, and 8, the processing gas supplied to the processing space 100 by forming an induced electric field using the high frequency antenna 5. Is shown as an example of plasma conversion. However, the method of converting the processing gas into plasma is not limited to the inductively coupled method.
For example, in the plasma processing apparatus 1 shown in FIG. 3, instead of arranging the high frequency antenna 5, the first high frequency power supply 512 is connected to each gas shower head portion 30a to 30d, and the mounting table 13 and the metal window 3 (gas shower head portion) are connected. 30a to 30d) may be formed as a parallel plate type plasma generating portion, and the processing gas may be converted into plasma by capacitive coupling.

Further, even when inductively coupled plasma using a high frequency antenna 5 is used, it is not an essential requirement that the gas shower head portions 30a to 30d and 30e are composed of a metal partial window 30, for example, quartz or the like. It may be a dielectric window made of a dielectric.

The treatment for the substrate G to be processed is not limited to the above-mentioned etching treatment and film formation treatment, but may be other film formation treatments for forming a metal film, an ITO film, an oxide film, etc. when forming a thin film. It can be used for various plasma treatments such as other etching treatments for etching these films and ashing treatments for resist films.

Further, the plasma processing devices 1, 1a and 1b can be used not only for the substrate G for the FPD but also for the various plasma treatments described above for the substrate G for the solar cell panel.

When the rectangular metal window 3 has a short side and a long side, the peripheral gas shower head portion 30c is divided into a peripheral gas shower head portion on the long side and a peripheral gas shower head portion on the short side, and the first is different from each other. The gas whose flow rate is individually adjusted may be distributed and supplied by using the distribution flow rate adjusting unit and the second distribution flow rate adjusting unit.

MFCs were used as the first distribution flow rate adjusting units 421a to 424a and the second distribution flow rate adjusting units 421b to 424b, but instead, the gas supplied was distributed according to a predetermined pressure ratio. A controller and a flow rate controller that distributes according to a predetermined flow rate ratio may be used.

G Processed circuit board 30a, 30b, 30e
Gas shower head part 30c, 30d
Peripheral gas shower head (gas shower head)
4a CF ₄ Gas supply unit 4b O ₂ Gas supply unit 4c Cl ₂ Gas supply unit 4d N ₂ Gas supply unit 4e Halogen-containing additive gas supply unit 4f SiCl ₄ Gas supply unit 4g N ₂ Gas supply unit 4h SiF ₄ Gas supply unit 4i O ₂ Gas supply unit 401 First distribution flow path 402 Second distribution flow path 41a First supply flow rate adjustment unit 41b Second supply flow rate adjustment unit 421a to 424a
First distribution flow rate adjusting unit 421b to 424b
Second distribution flow rate adjusting units 43a to 43d
Gas supply pipe 5 High frequency antenna 6 Control unit

Claims (10)

In a plasma processing apparatus that performs plasma processing with a plasma-ized processing gas on a substrate to be processed in a vacuum-exhausted processing space.
A processing container provided with a mounting table on which the substrate to be processed is placed and constituting a processing space in which the plasma processing is performed, and a processing container.
A gas discharge that constitutes the ceiling surface of the processing space and is provided in each of a plurality of regions formed by dividing the ceiling surface from the central portion side to the peripheral portion side in the radial direction to supply the processing gas to the processing space. Multiple gas shower heads with holes and
A plasma generating unit for converting the processing gas supplied to the processing space from the plurality of gas shower head units into plasma, and a plasma generating unit.
A first processing gas raw material supply unit for supplying a first processing gas raw material and a second processing gas raw material supply unit for supplying a second processing gas raw material contained in the processing gas.
A first supply flow rate adjusting unit for adjusting the flow rate of the first processing gas raw material supplied to the processing space from the first processing gas raw material supply unit.
The first processing gas raw material whose flow rate has been adjusted by the first supply flow rate adjusting unit is provided in each of a plurality of first distribution channels for distributing and supplying the first processing gas raw material to the plurality of gas shower head units. A plurality of first distribution flow rate adjusting units for adjusting the flow rate of the first raw material gas supplied to each gas shower head unit, and
A second supply flow rate adjusting unit for adjusting the flow rate of the second processing gas raw material supplied to the processing space from the second processing gas raw material supply unit.
The second processing gas raw material whose flow rate has been adjusted by the second supply flow rate adjusting unit is provided in each of the plurality of second distribution channels for distributing and supplying the second processing gas raw material to the plurality of gas shower head units. A plurality of second distribution flow rate adjusting units for adjusting the flow rate of the second raw material gas supplied to each gas shower head unit are provided .
The processing gas is an etching gas for etching the etching target film formed on the substrate to be processed, which is a glass substrate.
The second processing gas raw material is oxygen gas, and
The first and second distribution flow rate adjusting units provided in the plurality of first and second distribution flow paths have a magnitude of inclination of the end portion of the photoresist film patterned on the upper surface side of the etching target film. The first and second processing gas raw materials are such that the oxygen concentration of the etching gas supplied from the gas shower head portion at the position where the etching gas is supplied to these regions is changed according to the regions in which the etching gas is different. A plasma processing device characterized by the fact that the flow rate is set . The etching target film is a silicon-containing film and is
The first processing gas raw material is at least one of carbon tetrafluoride gas and nitrogen trifluoride gas.
The first and second distribution flow rate adjusting units provided in the plurality of first and second distribution flow paths are regions in which the end portion of the photoresist film patterned on the upper surface side of the etching target film has a large inclination. Of the etching gas supplied from the gas shower head portion at the position where the etching gas is supplied to the region where the inclination of the end portion of the photoresist film is smaller than that at the position where the etching gas is supplied. The plasma processing apparatus according to claim 1 , wherein the flow rates of the first and second processing gas raw materials are set so as to increase the oxygen concentration, respectively. The etching target film is a polycrystalline silicon film or a molybdenum film.
The first processing gas raw material is a gas selected from at least one of carbon tetrafluoride gas, sulfur hexafluoride gas, nitrogen trifluoride gas, and chlorine gas.
The first and second distribution flow rate adjusting units provided in the plurality of first and second distribution flow paths are regions where the inclination of the end portion of the photoresist film patterned on the upper surface side of the etching target film is small. Of the etching gas supplied from the gas shower head portion at the position where the etching gas is supplied to the region where the inclination of the end portion of the photoresist film is larger than that at the position where the etching gas is supplied. The plasma processing apparatus according to claim 1 , wherein the flow rates of the first and second processing gas raw materials are set so as to increase the oxygen concentration, respectively. In a plasma processing apparatus that performs plasma processing with a plasma-ized processing gas on a substrate to be processed in a vacuum-exhausted processing space.
A processing container provided with a mounting table on which the substrate to be processed is placed and constituting a processing space in which the plasma processing is performed, and a processing container.
A gas discharge that constitutes the ceiling surface of the processing space and is provided in each of a plurality of regions formed by dividing the ceiling surface from the central portion side to the peripheral portion side in the radial direction to supply the processing gas to the processing space. Multiple gas shower heads with holes and
A plasma generating unit for converting the processing gas supplied to the processing space from the plurality of gas shower head units into plasma, and a plasma generating unit.
A first processing gas raw material supply unit for supplying a first processing gas raw material and a second processing gas raw material supply unit for supplying a second processing gas raw material contained in the processing gas.
A first supply flow rate adjusting unit for adjusting the flow rate of the first processing gas raw material supplied to the processing space from the first processing gas raw material supply unit.
The first processing gas raw material whose flow rate has been adjusted by the first supply flow rate adjusting unit is provided in each of a plurality of first distribution channels for distributing and supplying the first processing gas raw material to the plurality of gas shower head units. A plurality of first distribution flow rate adjusting units for adjusting the flow rate of the first raw material gas supplied to each gas shower head unit, and
A second supply flow rate adjusting unit for adjusting the flow rate of the second processing gas raw material supplied to the processing space from the second processing gas raw material supply unit.
The second processing gas raw material whose flow rate has been adjusted by the second supply flow rate adjusting unit is provided in each of the plurality of second distribution channels for distributing and supplying the second processing gas raw material to the plurality of gas shower head units. A plurality of second distribution flow rate adjusting units for adjusting the flow rate of the second raw material gas supplied to each gas shower head unit are provided .
The processing gas is an etching gas for etching an aluminum film formed on a substrate to be processed, which is a glass substrate, and a silicon dioxide film on the upper layer side thereof.
The first processing gas raw material is chlorine gas, and the second processing gas raw material is nitrogen gas and halogen-containing gas.
The first and second distribution flow rate adjusting units provided in the plurality of first and second distribution flow paths are located on the central portion side of the gas shower head portion located on the peripheral portion side of the ceiling surface. The flow rate of the first and second processing gas raw materials is set so that the distribution ratio of the nitrogen gas and the halogen-containing gas to the chlorine gas of the etching gas supplied from the gas shower head portion becomes small, respectively. And, a plasma processing device characterized by. In a plasma processing apparatus that performs plasma processing with a plasma-ized processing gas on a substrate to be processed in a vacuum-exhausted processing space.
A processing container provided with a mounting table on which the substrate to be processed is placed and constituting a processing space in which the plasma processing is performed, and a processing container.
A gas discharge that constitutes the ceiling surface of the processing space and is provided in each of a plurality of regions formed by dividing the ceiling surface from the central portion side to the peripheral portion side in the radial direction to supply the processing gas to the processing space. Multiple gas shower heads with holes and
A plasma generating unit for converting the processing gas supplied to the processing space from the plurality of gas shower head units into plasma, and a plasma generating unit.
A first processing gas raw material supply unit for supplying a first processing gas raw material and a second processing gas raw material supply unit for supplying a second processing gas raw material contained in the processing gas.
A first supply flow rate adjusting unit for adjusting the flow rate of the first processing gas raw material supplied to the processing space from the first processing gas raw material supply unit.
The first processing gas raw material whose flow rate has been adjusted by the first supply flow rate adjusting unit is provided in each of a plurality of first distribution channels for distributing and supplying the first processing gas raw material to the plurality of gas shower head units. A plurality of first distribution flow rate adjusting units for adjusting the flow rate of the first raw material gas supplied to each gas shower head unit, and
A second supply flow rate adjusting unit for adjusting the flow rate of the second processing gas raw material supplied to the processing space from the second processing gas raw material supply unit.
The second processing gas raw material whose flow rate has been adjusted by the second supply flow rate adjusting unit is provided in each of the plurality of second distribution channels for distributing and supplying the second processing gas raw material to the plurality of gas shower head units. A plurality of second distribution flow rate adjusting units for adjusting the flow rate of the second raw material gas supplied to each gas shower head unit are provided .
The processing gas is a film forming gas for forming a silicon-containing film formed on a substrate to be processed, which is a glass substrate.
The first processing gas raw material is at least one of silicon tetrafluoride gas and silicon tetrachloride gas, and the second processing gas raw material is nitrogen gas or oxygen gas.
The second distribution flow path merges with the first distribution flow path on the downstream side of the first distribution flow rate adjusting unit, respectively.
In the first distribution flow rate adjusting unit and the first distribution flow rate adjustment unit, the pressure in the flow path from the first distribution flow rate adjustment unit to the first distribution flow rate adjustment unit is the first at room temperature. A plasma processing apparatus characterized in that a flow rate is set so as to supply a first processing gas raw material having a flow rate maintained at a pressure lower than the vapor pressure of the processing gas raw material . Of the plurality of regions formed by dividing the ceiling surface in the radial direction, the annular region on the peripheral portion side is divided into a plurality of regions formed by dividing the annular region in the circumferential direction, and the processing space is processed. A plurality of peripheral gas shower head portions, which are gas shower head portions having gas discharge holes for supplying gas, are provided.
From the first distribution flow path provided with the first distribution flow rate adjusting section and the second distribution flow path provided with the second distribution flow rate adjusting section, the peripheral gas shower head section is referred to. The plasma processing apparatus according to any one of claims 1 to 5, wherein the first processing gas raw material and the second processing gas raw material are distributed and supplied. The planar shape of the ceiling surface is rectangular, and the peripheral gas shower head portion is sandwiched between the peripheral gas shower head portion including the corner portion of the rectangular shape and the adjacent corner portions, and has the rectangular shape. A peripheral gas shower head part including the side part of the
The peripheral gas shower head portion of the corner portion is supplied by distributing the first and second processed gas raw materials from the common first and second distribution channels, and the peripheral gas shower head portion of the peripheral portion is supplied. 6. The first and second processing gas raw materials are distributed and supplied from a common first and second distribution channels different from those of the peripheral gas shower head portion of the corner portion. The plasma processing apparatus according to. The exhaust port for performing vacuum exhaust in the processing space is provided at a position below the annular region where the peripheral gas shower head portion is provided, or at a position on the outer side of the lower position. The plasma processing apparatus according to claim 6 or 7 . The second distribution flow path is one of claims 1 to 8 , wherein each of the second distribution flow paths joins the first distribution flow path on the downstream side of the first distribution flow rate adjusting unit. The plasma processing apparatus described. The plasma generating portion is a plasma antenna arranged above the gas shower head portion and for converting the processed gas into plasma by inductively coupled.
One of claims 1 to 9 , wherein each of the plurality of gas shower head portions is configured as a metal window made of a conductive partial window, and adjacent gas shower head portions are insulated from each other. The plasma processing apparatus according to one.

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