TWI399808B - Etching method and etching device - Google Patents

Description

Etching method and etching device

The present invention is a technique for etching an film to be formed formed on a substrate such as a semiconductor wafer by using a gas containing carbon and a halogen.

In the process of a semiconductor device or an LCD substrate, there is an etching process for performing shape processing of a film, and an apparatus for performing this process is used in various forms. One of them is, for example, a parallel plate type plasma etching apparatus in which, for example, a parallel plate electrode composed of a pair of upper electrodes and lower electrodes is disposed in a processing chamber, and a processing gas is introduced into the processing chamber, and the counter electrode is When a high frequency is applied to one of the electrodes, a high-frequency electric field is formed between the electrodes, and a plasma of the processing gas is formed by the high-frequency electric field. For example, the semiconductor wafer W (hereinafter referred to as "wafer W") is etched.

Here, for example, in a semiconductor device, a low-k film (so-called Low-k film) which is reviewed or put into practical use as an interlayer insulating film or a gate insulating film contains germanium (Si) and oxygen (0). An oxide film (SiO film) is added with a carbon-based SiOC film or a carbon or hydrogen-added SiOCH film. However, when etching such films, for example, carbon (C), fluorine (F), and chlorine (Cl) are contained. A halogen gas such as bromine (Br) is used as a processing gas.

In the etching, both the etching action of the hole (concave portion) by the etching of the etching liquid is performed, and the polymer is formed on the side wall of the hole to protect the side wall. For example, when a gas containing carbon and fluorine (hereinafter referred to as a CF-based gas) is used as a processing gas and an SiO-based film is etched, an active species of CF generated by plasma-forming of a CF-based gas exhibits an etching action. And the tasks of both the polymerization and so on.

Examples of the CF-based gas include CF ₄ gas, CHF ₃ gas, C ₂ F ₆ gas, C ₃ F ₈ gas, C ₄ F ₈ gas, C ₄ F ₆ gas, C ₅ F ₈ gas, and the like. In the case of a gas having a large etching effect or a gas having a large polymerization effect, even if the target film to be etched is the same film, the CF film gas is used in accordance with the change in the film thickness ratio of the underlayer film or the photoresist film. Choose the most suitable gas type.

Further, for example, in the parallel plate type plasma etching apparatus described above, in order to improve the uniformity in the wafer surface of the etching characteristics such as the etching rate or the processed size after etching, a plurality of gas ejection holes are formed. The upper electrode of the shower head type supplies a flow rate of the processing gas to, for example, the central region and the peripheral region of the wafer W.

However, in the gas of the CF-based gas, there is no method for determining the uniform supply flow ratio to the central region or the peripheral region. In order to perform the above-described high in-plane uniformity, it is necessary to try to make an error until the above-mentioned determination is made. The supply flow ratio of the central area and the surrounding area is determined, and the condition of the flow ratio is determined to be time-consuming and time consuming.

Patent Document 1 discloses that when a photoresist and a TEOS are etched by a mixed gas containing a C ₅ F ₈ gas, the flow rates are different from the two gas discharge ports forming the concentric circular shower head. The mixed gas is a technique in which only the peripheral region reduces the flow rate of oxygen introduced into the gas, thereby improving the etching rate selection ratio (TEOS/resist) in the peripheral region. However, the technique of this document 1 does not describe any method for determining the flow ratio of the flow rate of the central region of the wafer W and the flow rate of the peripheral region when the etching process is performed by the CF-based gas.

[Patent Document 1] JP-A-2002-184764

The present invention has been made in view of the above circumstances, and an object thereof is to provide a technique for improving the uniformity in the surface of an etching process when etching is performed using a gas containing carbon and a halogen.

In view of this, the etching method of the present invention is a method of etching an etching film of a substrate by a gas supply portion and a processing gas, and the gas supply portion is movable from a central region and a direction opposite to a central region of the substrate. The processing gas is supplied to the substrate independently in a peripheral region of the peripheral region of the substrate, and the processing gas system includes a first gas containing carbon having a carbon number of 2 or less in one molecule and a halogen, and is characterized in that the gas supply unit is The supply amount of the first gas per unit time per unit area of the gas supply surface is such that the central portion is supplied more than the peripheral region, and the substrate is etched while supplying the processing gas from the gas supply portion. The film is etched.

Further, in the etching method of the present invention, the etching method of the substrate is etched by the gas supply unit and the processing gas, and the gas supply unit is detachable from the central region of the central region facing the substrate and the opposite substrate. The processing gas system includes a gas containing carbon having a carbon number of 3 or more and a halogen in a peripheral region of the peripheral region, and is characterized in that the gas is supplied to the gas supply portion. The supply amount of the second gas per unit time per unit area of the supply surface is such that the etching gas is supplied to the substrate while supplying the processing gas from the gas supply unit so that the peripheral region is larger than the central region. Etching.

Further, in the etching method of the present invention, the etching method of the substrate is etched by the gas supply unit and the processing gas, and the gas supply unit is detachable from the central region of the central region facing the substrate and the opposite substrate. In the peripheral region of the peripheral region, the processing gas is independently supplied to the substrate, and the processing gas system mixes the first gas containing carbon and halogen having 2 or less carbon atoms in one molecule and the carbon number of 3 or more in one molecule. The second gas of carbon and halogen is characterized in that the mixing ratio of the second gas to the first gas is the same in the central region and the peripheral region of the gas supply portion, and the total number of halogen atoms supplied by the first gas is borrowed. When the total number of the halogen atoms supplied from the second gas is larger, the supply amount of the mixed gas per unit time per unit area of the gas supply surface of the gas supply unit is such that the central region is larger than the peripheral region. When the processing gas is supplied from the gas supply unit, when the total number of halogen atoms supplied from the first gas is smaller than the total number of halogen atoms supplied from the second gas, The supply amount of the mixed gas per unit time of the gas supply surface of the gas supply unit is larger than the central area, and the processing gas is supplied from the gas supply unit to the substrate. The film is etched by etching.

Here, the supply amount of the mixed gas of the first gas and the second gas is such that the central region is larger than the peripheral region, or the peripheral region is larger than the central region, and the processing gas is supplied from the gas supply portion. The process is performed by adjusting at least one of the flow rate of the process gas and the dilution rate of the process gas of the diluent gas.

Further, in the etching method of the present invention, the etching method of the substrate is etched by the gas supply unit and the processing gas, and the gas supply unit is detachable from the central region of the central region facing the substrate and the opposite substrate. In the peripheral region of the peripheral region, the processing gas is independently supplied to the substrate, and the processing gas system mixes the first gas containing carbon and halogen having 2 or less carbon atoms in one molecule and the carbon number of 3 or more in one molecule. The second gas of the carbon and the halogen is characterized in that the first processing gas in which the first gas and the second gas are mixed at the first mixing ratio is supplied to the central region of the gas supply unit, and is supplied to the peripheral region of the gas supply unit. When the second processing gas of the first gas and the second gas is mixed in the second mixing ratio, when the total number of halogen atoms supplied from the first gas is larger than the total number of halogen atoms supplied from the second gas, The supply amount of the mixed gas per unit time per unit area of the gas supply surface of the gas supply unit is such that the supply amount of the first processing gas is larger than the supply amount of the second processing gas When the processing gas is supplied from the gas supply unit, when the total number of halogen atoms supplied from the first gas is smaller than the total number of halogen atoms supplied from the second gas, the gas supply surface of the gas supply unit is The supply amount of the mixed gas per unit time per unit area is such that the supply amount of the first processing gas is smaller than the supply amount of the second processing gas, and the processing gas is supplied from the gas supply unit. The etched film of the substrate is etched.

Further, in the etching method of the present invention, the etching method of the substrate is etched by the gas supply unit and the processing gas, and the gas supply unit is detachable from the central region of the central region facing the substrate and the opposite substrate. In the peripheral region of the peripheral region, the processing gas is independently supplied to the substrate, and the processing gas system mixes the first gas containing carbon and halogen having 2 or less carbon atoms in one molecule and the carbon number of 3 or more in one molecule. The second gas of the carbon and the halogen is characterized in that the supply amount of the first gas per unit time per unit area of the gas supply surface of the gas supply unit is such that the central region is larger than the peripheral region. The gas supply unit supplies the processing gas, and the supply amount of the second gas per unit time per unit area of the gas supply surface of the gas supply unit is larger than the central area. The supply unit supplies the processing gas while etching the film to be etched of the substrate.

Further, in the etching method of the present invention, the etching method of the substrate is etched by the gas supply unit and the processing gas, and the gas supply unit is detachable from the central region of the central region facing the substrate and the opposite substrate. In the peripheral region of the peripheral region, the processing gas is independently supplied to the substrate, and the processing gas system mixes the first gas containing carbon and halogen having 2 or less carbon atoms in one molecule and the carbon number of 3 or more in one molecule. The second gas of carbon and halogen is characterized in that, in the central region and the peripheral region of the gas supply unit, when the supply amount of the first gas is the same, the unit supply time per unit area of the gas supply surface of the gas supply unit is When the supply amount of the second gas is larger than the central region, the processing gas is supplied from the gas supply unit, and when the supply amount of the second gas is the same in the central region and the peripheral region of the gas supply unit, The supply amount of the first gas per unit time per unit area of the gas supply surface of the gas supply unit is such that the central area is larger than the peripheral area. The gas supply unit supplies the processing gas and etches the film to be etched of the substrate.

Here, the supply amount of the first gas is the first to supply the processing gas from the gas supply unit so that the center region is larger than the peripheral region, and the first flow rate and the dilution gas are adjusted by the first gas. At least one of the dilution rates of the gas is performed. Further, the supply amount of the second gas is such that the flow rate of the second gas and the second gas of the diluent gas are adjusted by supplying the processing gas from the gas supply unit such that the peripheral region is larger than the central region. At least one of the dilution rates is carried out.

Further, in the etching method of the present invention, the etching method of the substrate is etched by the gas supply unit and the processing gas, and the gas supply unit is detachable from the central region of the central region facing the substrate and the opposite substrate. In the peripheral region of the peripheral region, the processing gas is independently supplied to the substrate, and the processing gas system mixes the first gas containing carbon and halogen having 2 or less carbon atoms in one molecule and the carbon number of 3 or more in one molecule. The second gas of carbon and halogen is characterized in that when the total number of halogen atoms supplied from the first gas is larger than the total number of halogen atoms supplied from the second gas, the gas supply by the gas supply unit is The total number of halogen atoms per unit time per unit area of the surface is larger than the peripheral area, and the composition and amount of the processing gas supplied from the gas supply unit are set by the first gas. When the total number of halogen atoms is smaller than the total number of halogen atoms supplied from the second gas, the halogen per unit area of the gas supply surface of the gas supply unit is halogen per unit time. The total amount of atoms is such that the peripheral area is larger than the central area, and the composition and amount of the processing gas supplied from the gas supply unit are set.

At least one of CH ₂ F ₂ gas, CHF ₃ gas, CF ₄ gas, and C ₂ F ₆ gas may be used as the first gas, and at least C ₃ F ₈ gas and C ₄ F ₈ gas may be used as the second gas. Any of C ₄ F ₆ gas, C ₅ F ₈ gas.

Such an etching method can be applied, for example, to an etching apparatus including a processing container in which a mounting table on which a substrate is placed is provided, and a gas supply unit that can be disposed in the processing container The inside is disposed opposite to the mounting table, and a surface facing the mounting table is provided with a gas supply surface for the substrate placed on the mounting table from a central region of the central region opposite to the substrate And a process gas for independently supplying carbon and halogen to the peripheral region of the peripheral region of the substrate; means for adjusting the pressure inside the processing container; means for generating plasma in the interior of the processing container; a means for adjusting a flow rate of the processing gas supplied to the gas supply unit; and a control unit that controls the respective means to plasma the processing gas, and the etched film of the substrate is performed by the plasma Etching.

As described above, in the present invention, when etching an etching film of a substrate by using a processing gas containing a gas containing carbon and a halogen, the carbon and the halogen are contained in accordance with the carbon number of the gas containing the carbon and the halogen. The supply amount of the gas to the central portion of the gas supply surface of the gas supply portion is larger than that of the peripheral region, or the supply amount to the peripheral region is more controlled than the central region, so that the etching rate or the processing accuracy after etching can be ensured. In-plane uniformity with good etching characteristics.

First, an example of a plasma etching apparatus for carrying out the etching method of the present invention will be briefly described with reference to Fig. 1 . In the drawing, reference numeral 1 denotes, for example, a processing chamber constituting a cylindrical processing container, which is formed, for example, by aluminum which is subjected to an alumite treatment (anodizing treatment) and is grounded. A columnar mounting base 2 is formed at the bottom of the processing chamber 1 to mount a substrate such as a semiconductor wafer (hereinafter referred to as "wafer"). In the figure, 21 is an insulating plate such as ceramics, 22 is a mounting table support, and a high-pass filter (HPF) 23 is connected to the mounting table 2. In the figure, reference numeral 24 denotes a refrigerant chamber. Here, for example, a refrigerant such as liquid nitrogen is circulated and supplied to be transferred to the mounting table 2.

The mounting table 2 has a disk shape in which a central portion is formed in a convex shape, and an electrostatic chuck 3 having a shape similar to that of the wafer W is provided on the upper surface of the mounting table 2, and a DC voltage of 1.5 kV is applied from the DC power source 32 to the electrode 31, for example. Thereby, the wafer W can be electrostatically absorbed by, for example, Coulomb force. 33 is a gas passage for supplying a heat transfer medium such as helium (He) gas or the like to the back surface of the wafer W supported on the mounting table 2, and the heat of the mounting table 2 is transferred to the heat transfer medium through the heat transfer medium. Wafer W, wafer W will be maintained at a specific temperature. 25 is provided in such a manner as to be able to surround the wafer W placed on the electrostatic chuck 3, for example, an annular focus ring formed of a conductive material such as tantalum, thereby improving etching. Uniformity.

Above the mounting table 2, a gas supply portion 4 that faces the mounting table 2 in parallel with, for example, a substantially cylindrical upper electrode is provided. The gas supply unit 4 is composed of an electrode plate 42 and an electrode support member 43. The electrode plate 42 is a surface that faces the mounting table 2, and has a plurality of discharge holes 41. The electrode support body 43 is supported by The electrode plate 42 is made of a water-cooling structure made of a conductive material, for example, aluminum whose surface is treated with an aluminum oxide film.

The electrode support 43 has a gas introduction chamber formed therein, and the gas introduction chamber is divided into a first gas chamber 45 which is divided into a central region of the wafer W facing the inside by a ring-shaped partition wall 44, and The second gas chamber 46 is opposed to the peripheral region of the wafer W on the outer side. In this manner, the lower surfaces of the first gas chamber 45 and the second gas chamber 46 are constituted by the electrode plates 42 having the discharge holes 41 forming the gas supply surface.

Then, as shown in FIG. 2, the first gas chamber 45 is connected to the common processing gas supply system 53 via the first gas introduction path 51 including the flow rate adjustment unit F1, and the second gas chamber 46 is provided with the flow rate adjustment unit F2. The second gas introduction path 52 is connected to the common process gas supply system 53. In the figure, 47 is an insulating material, 48 is a high-frequency absorbing member, and 49 is an insulating material for supporting the gas supply unit 4 in the processing chamber 2. Further, the mounting table 2 and the gas supply unit 4 are provided, for example, at intervals of 10 to 60 mm.

Here, the target film to be etched is a low dielectric constant film (so-called Low-k film) as described above, such as a SiOC film, or a SiOCH film, a SiO ₂ film, a SiOF film, a Si-H-containing SiO ₂ film, and a Hydrogens Slises. -Quioxane (HSQ) film, porous cerium oxide film, methyl group-containing SiO ₂ film, MethlSlises-Quioxane (MSQ) film, porous MSQ film, etc., in the case of the above-mentioned processing gas, the main etching gas is carbon-containing And a gas of a gas such as a halogen atom such as fluorine, bromine or chlorine. Here, when the main etching gas is a CF-based gas containing carbon and fluorine, there are a first gas having a carbon number of 2 or less such as CF ₄ gas, CHF ₃ gas, or C ₂ H ₆ gas, or C _{3 .} The second gas having a carbon number of 3 or more such as F ₈ gas, C ₄ F ₆ gas, C ₄ F ₈ gas, or C ₅ H ₈ gas. As the processing gas, a mixed gas of the CF-based gas and a rare gas, a N ₂ gas, an H ₂ gas, an O ₂ gas, a CO gas, a CO ₂ gas, or the like, and a diluent gas containing no halogen atom, or a plurality of CF systems may be used. gas.

The processing gas supply system 53 includes, for example, the first gas supply source 54, the second gas supply source 55, and the diluent gas supply source 56, which are respectively connected via a supply path 57 including flow rate adjustment units F3 to F5. The first and second gas introduction paths 51 and 52 are provided. The flow rate adjusting units F1 to F5 are means for adjusting the supply amount of the processing gas, and include a valve and a mass flow controller, and the control unit 6 controls the operation to thereby specify the first gas and the second flow rate. The gas and the diluent gas are mixed to prepare a processing gas, and the mixed processing gas is supplied through the first gas introduction chamber 45 and the second gas introduction chamber 46 at a specific flow rate.

The bottom of the processing chamber 1 is connected to a vacuum pump 12 such as a turbo-molecular pump, which is a means for adjusting the pressure in the processing chamber 1 via the exhaust pipe 11, whereby the processing chamber 1 can be Vacuum is applied to a specific reduced pressure environment, such as a specific pressure below 1 Pa. Further, a gate valve 13 is provided on the side wall of the processing chamber 1, and the wafer W can be transferred between adjacent load lock chambers (not shown) while the gate valve 13 is opened.

The gas supply unit 4 as the upper electrode is connected to the first high-frequency power source 61 that is a means for generating plasma via the integrator 62 and the power supply rod 63, and is connected to the low-pass filter (LPF) 64. The first high-frequency power source 61 has a frequency of 27 MHz or more, and by applying such a high frequency, it is possible to form a plasma having a high degree of density in a desired dissociation state in the processing chamber 1, and plasma processing under a low pressure condition can be performed. In this example, the first high-frequency power source 61 is a 60 MHz user.

The second high-frequency power source 65 is connected to the mounting table 2 as the lower electrode via the integrator 66 by a power supply line. The second high-frequency power source 65 has a frequency in the range of 100 kHz to 10 MHz, and by applying such a range of frequencies, it is possible to impart an appropriate ion action without causing damage to the substrate, that is, the wafer W. This example is for people using 2MHz.

Next, an etching method of the present invention performed in the plasma etching apparatus will be described. First, the operation of the plasma etching apparatus will be described. The gate valve 13 is opened from a load lock chamber (not shown) to carry the substrate W, that is, the wafer W, into the processing chamber 1, and is placed on the electrostatic chuck 3 from the high voltage direct current. The power source 32 applies a DC voltage to electrostatically attract the wafer W to the electrostatic chuck 3. Next, the gate valve 13 is closed, and the inside of the processing chamber 1 is evacuated to a specific degree of vacuum by the vacuum pump 12.

Then, the processing gas supplied to the gas supply unit 4 by the flow rate adjustment units F1 and F2 is introduced from the processing gas supply unit 53 via the first processing gas introduction path 51 and the second processing gas introduction path 52. 1 gas chamber 45 and second gas chamber 46. In this manner, the processing gas is supplied from the first gas chamber 45 to the central region of the wafer W, and the processing gas is supplied from the second gas chamber 46 to the peripheral region of the wafer W, and the pressure in the processing chamber 1 is maintained at a specific level. value.

Then, a high frequency of 27 MHz or more, for example, 60 MHz, is applied from the first high frequency power source 61 to the gas supply unit 4. Thereby, a high-frequency electric field is generated between the gas supply unit 4 and the mounting table 2, and the processing gas is dissociated and plasma-formed, whereby the wafer W is etched by the plasma.

On the other hand, a high frequency of 100 kHz to 10 MHz, for example, 2 MHz, is applied from the second high frequency power source 65 to the mounting table 2. Thereby, ions in the plasma are introduced to the stage 2, and the anisotropy of etching is improved by ion assist. The wafer W subjected to the specific etching treatment removes the electrostatic attraction of the electrostatic chuck 3, opens the gate valve 13, and carries it out from the processing chamber 1 to the outside, and transports it to the next process.

Here, in the etching method of the present invention, when a main etching gas is a gas containing a CF-based gas, for example, an SiOC film or the like based on an SiO film is etched, the CF is supplied in accordance with the carbon number of the CF-based gas. The control of the central region of the gas to the wafer W is more than the peripheral region or the supply to the peripheral region is more than the central region. Therefore, the following description will be made.

First, the case where the CF-based gas and the diluent gas are mixed in advance before being supplied to the plasma etching apparatus will be described. Since the composition of the processing gas supplied to the apparatus is the same, the gas supply unit for controlling the processing gas is controlled. The supply flow rate of the first gas chamber 45 and the supply flow rate to the second gas chamber 46 control the supply amount of the CF-based gas in the processing gas to the central region and the supply amount to the peripheral region.

Specifically, when the CF-based gas is one type, the first gas having a carbon number of 2 or less is used as the main etching gas, and the unit supply time per unit area of the gas supply surface of the gas supply unit 4 is described. The supply amount of the first gas is supplied from the gas supply unit 4 so that the central area is larger than the peripheral area.

In other words, the flow rates of the first gas and the diluent gas are adjusted to a specific flow rate by the flow rate adjusting units F3 and F5, and the processing gas in which the first gas and the diluent gas are mixed at a specific mixing ratio is adjusted. Then, by the flow rate adjusting units F1 and F2, the amount of the processing gas supplied from the first gas chamber 45 is larger than the amount of the processing gas supplied to the second gas chamber 46, and the first gas introduction path 51 and The second gas introduction path 52 introduces the processing gas at a specific flow rate. As a result, more first gas is supplied in the central region of the gas supply surface than in the peripheral region.

In the present invention, the supply amount of the first gas means the amount of supply per unit area of the gas supply surface per unit time, and the first gas in the central region of the gas supply surface is larger than the peripheral region. The supply means that the number of moles of the first gas supplied to the central region is larger than the number of moles of the first gas supplied to the peripheral region.

In addition, when the second gas having a carbon number of 3 or more is used as the main etching gas, the supply amount of the second gas per unit time of the gas supply surface of the gas supply unit 4 is the peripheral area than the center. The processing gas is supplied from the gas supply unit 4 in a plurality of regions.

In other words, the flow rates of the second gas and the diluent gas are adjusted to a specific flow rate by the flow rate adjusting units F4 and F5, and the processing gas in which the second gas and the diluent gas are mixed at a specific mixing ratio is adjusted. Then, by the flow rate adjusting units F1 and F2, the supply amount of the processing gas in the second gas chamber 46 is larger than the amount of the processing gas supplied to the first gas chamber 45, and the first gas introduction path 51 and The second gas introduction path 52 introduces the processing gas at a specific flow rate. As a result, more second gas is supplied in the peripheral region of the gas supply surface than in the central region.

Here, the central region of the gas supply surface is a region corresponding to a gas supply surface of the first gas chamber 45 and a radius of 7 to 10 (a square root of 1/2) of the radius of the wafer W. The peripheral region of the supply surface is a region corresponding to the gas supply surface of the second gas chamber 46 and facing the region outside the central region of the wafer W. The area of this central area and the peripheral area is designed to be roughly the same. Further, in the plasma etching apparatus, the gas supply surface of the gas supply unit 4 is opposed to the wafer W, and the processing gas is supplied from the first gas chamber 45 of the gas supply unit 4 to the central region of the wafer W. The gas chamber 46 is supplied to the peripheral region of the wafer W. Therefore, when the supply amount of the first gas is larger than the peripheral region in which the gas supply surface is formed, the supply amount of the first gas on the surface of the wafer is more in the central region than in the peripheral region. When the supply amount of the gas is larger than the central region in which the gas supply surface is formed, the amount of supply of the second gas on the surface of the wafer is larger in the peripheral region than in the central region.

In this case, in the plasma etching apparatus, the number of the discharge holes (the discharge holes supplied to the central region of the wafer W) 41 formed in the lower surface of the first gas chamber 45 and the second gas chamber 46 are formed. The number of the discharge holes (the discharge holes supplied to the peripheral region of the wafer W) 41 is the same, and the gas flow rate ratio in the center region/peripheral region of the gas supply surface is set to a ratio of 5:5. The flow rate of the gas ejected from the discharge port 41 is set to be the same, but the number of the discharge holes 41 formed in the lower surface of the first gas chamber 45 is different from the number of the discharge holes 41 formed in the lower surface of the second gas chamber 46. Or the discharge hole 41 formed in the lower surface of the first gas chamber 45 and the discharge hole 41 formed in the lower surface of the second gas chamber 46, and when the conductance to the discharge hole 41 is different, it is necessary to correspond to this. Adjustment.

For example, when the ratio of the number of the discharge holes 41 formed in the lower surface of the first gas chamber 45 to the number of the discharge holes 41 formed in the lower surface of the second gas chamber 46 to the peripheral region is 2:1, The supply flow rate of the gas to the central region: the supply flow rate to the peripheral region = 1:2, and the supply flow rate to the central region of the processing gas in the plasma etching device: to the peripheral region The distribution ratio of the supply flow rate = 5:5 is equivalent to the supply ratio. Therefore, for example, when the C ₄ F ₈ gas is used as the main processing gas, the ratio of the processing gas to the peripheral region may be 2/3 or more.

Next, the case where the CF-based gas is two or more types will be described. For example, when the first gas and the second gas are used in combination, the flow rate adjusting units F3 to F5 adjust the processing gas obtained by mixing the first gas, the second gas, and the diluent gas at a specific mixing ratio. Then, the total number of introductions of the halogen atoms of the first gas and the second gas is calculated, and the flow rate is determined by mixing a CF gas having a larger total number. This is because the number of halogen atoms governs the etching efficiency, so the gas having a large number of halogen atoms dominates the uniformity.

For example, when the first gas is CF ₄ gas and the second gas is C ₄ F ₈ gas, and the gas is a processing gas mixed at a mixing ratio of CF ₄ : C ₄ F ₈ = 15:6, CF _The total number of introductions of F in the gas is 4 × 15 = 60, and the total number of introduction of F in the C ₄ F ₈ gas is 8 × 6 = 48, so that the total number of introductions of F from the CF ₄ gas is large. Then, the flow rate is determined by the CF ₄ gas, and the flow rate adjusting units F1 and F2 are controlled so that the processing gas is higher than the second gas chamber 46 so that the supply amount of the processing gas is larger in the central region of the gas supply surface than in the peripheral region. More supply amount is introduced into the first gas introduction chamber 45.

In addition, when the total number of halogen atoms supplied from the first gas is smaller than the total number of halogen atoms supplied from the second gas, the supply amount of the processing gas is higher than the center in the peripheral region of the gas supply surface. The flow rate adjustment units F1 and F2 are controlled in a plurality of regions, and a larger supply amount of the processing gas than the first gas chamber 45 is introduced into the second gas chamber 46.

Next, a second embodiment of the present invention will be described. This embodiment is a component that independently controls the processing gas supplied to the central region and the peripheral region of the gas supply surface of the gas supply unit 4, and is implemented, for example, in the plasma etching apparatus shown in Fig. 3 . In the apparatus, for example, the first gas introduction path 51 is connected to the first gas supply source 61, the second gas supply source 62, and the diluent gas supply source 63 via a supply path including the flow rate adjustment units F1, F6 to F8, respectively. Further, the second gas introduction path 52 is connected to the first gas supply source 64, the second gas supply source 65, and the diluent gas supply source 66 via a supply path including the flow rate adjustment units F2 and F9 to F11, respectively.

The flow rate adjustment units F1, F2, F6 to F11 are controlled by the control unit 6, and the first gas chamber 45 and the second gas can be supplied to the first gas chamber 45 and the second gas via the first gas introduction path 51 and the second gas introduction path 52. The chamber 46 is supplied with a processing gas (a processing gas having a different dilution ratio) in which the mixing ratio of each of the first gas, the second gas, and the diluent gas is different. The other configuration is the same as the plasma etching apparatus shown in Fig. 1.

Moreover, since the composition of the processing gas supplied to the apparatus can be changed in this example, when the composition of the processing gas is the same or when only the CF-based gas is supplied, the first gas chamber 45 and the second gas chamber 46 can be controlled. The supply flow rate of the processing gas is controlled by the total number of fluorine atoms (halogen atoms) supplied to the central region of the gas supply surface and the total number of fluorine atoms supplied to the peripheral region, or may be made to the first gas chamber The supply flow rate of the processing gas of 45 and the second gas chamber 46 is the same, and the fluorine atom supplied to the central region of the gas supply surface is changed by changing the dilution ratio of the dilution gas of the CF-based gas, which is the composition of the processing gas. The total number of controls and the total number of fluorine atoms supplied to the surrounding area are controlled.

When the main etching gas is a first gas having a carbon number of 2 or less, the supply amount of the first gas to the first gas chamber 45 and the second gas chamber 46 is controlled to be supplied to the gas supply surface. The total number of fluorine atoms in the central region is greater than the total number of fluorine atoms supplied to the peripheral region of the gas supply surface.

For example, when the first gas is CF ₄ gas, and the diluent gas is not used, the flow rate adjustment unit F1, F6 causes the flow rate of the CF ₄ gas to the first gas chamber 45 to be 100 sccm, and the flow rate adjusting portion F2, F9 The supply flow rate of the CF ₄ gas to the second gas chamber 46 is 50 sccm, so that the supply flow rate to the central region of the gas supply surface is 100 sccm, and the supply flow rate to the peripheral region is 50 sccm, and the fluorine atom is controlled. The total amount of supply to the central region of the gas supply surface is more than that of the peripheral region. In this case, the flow rate adjustment unit provided between the first gas supply source 61, the second gas supply source 62, and the first gas chamber 45, or the first gas supply source 64, the second gas supply source 65, and the second There may be one flow rate adjusting portion between the gas chambers 46.

Further, for example, when the first gas is CF ₄ gas and the diluent gas is Ar gas, when the dilution ratio of the first gas is changed in the central region and the peripheral region of the gas supply surface, the flow rate adjusting units F6 and F8 are used. The first gas and the diluent gas are supplied to the first gas introduction path 51 at a flow rate of 50 sccm and 100 s ccm, respectively, and the first gas and the diluent gas are supplied to the first gas and the dilution gas at 50 sccm and 300 sccm, respectively, by the flow rate adjusting portions F9 and F11. The second gas introduction path 52. Then, the flow rate adjustment unit F1, F2 adjusts the flow rate, and the processing gas of the same flow rate is supplied from the first gas introduction path 51 and the second gas introduction path 52 to the first gas chamber 45 and the second gas introduction chamber 46, respectively.

In this manner, the flow rates of the processing gases supplied to the first gas chamber 45 and the second gas chamber 46 are the same, and the dilution ratio of the diluent gas used for the first gas in the processing gas supplied to the second gas chamber 46 is the same. The processing gas supplied to the first gas chamber 45 is larger, and as a result, it is controlled that the total number of fluorine atoms supplied to the central region of the gas supply surface is larger than that of the peripheral region.

Similarly, when the second gas having a carbon number of 3 or more is used, the amount of the second gas supplied to the central region of the gas supply surface and the amount of the second gas supplied to the peripheral region are controlled to be supplied to The total number of fluorine atoms of the second gas in the central region of the gas supply surface is smaller than the total number of fluorine atoms from the second gas supplied to the peripheral region.

Further, in this case, similarly to the first gas, when the composition of the processing gas is the same or when only the CF-based gas is supplied, the second gas chamber 46 is supplied with more second gas than the first gas chamber 45, and the fluorine can be controlled to be fluorine. The total number of atoms supplied to the peripheral region of the gas supply surface is larger than the central region, or the supply amount of the processing gas to the first gas chamber 45 and the second gas chamber 46 is the same, and the processing gas is changed by The composition of the second gas is a dilution ratio of the diluent gas, and it is controlled that the total amount of fluorine atoms supplied to the peripheral region of the gas supply surface is larger than that of the central region.

In addition, when the first gas having a carbon number of 2 or less and the second gas having a carbon number of 3 or more are mixed, the total number of introduced halogen atoms of each CF-based gas is calculated, and the CF-based gas having a larger total number is added to determine the gas supply. One of the central region or the peripheral region of the surface introduces a large amount of fluorine atoms.

For example, when the processing gas having a different mixing ratio of the first gas and the second gas is supplied to each of the first gas chamber 45 and the second gas chamber 46, for example, the first gas and the second gas are supplied to the first gas chamber 45. The first processing gas and the second processing gas are supplied to the first processing gas in the second gas chamber 46 when the first gas and the second gas are mixed in the second mixing ratio. In the whole, the total number of introductions of the halogen atoms of each of the CF-based gases is calculated, and the amount of the first gas supplied to the first gas chamber 45 and the second gas chamber 46 are determined by blending the CF gas having a larger total amount. 2 The amount of gas supplied.

In other words, when the number of introduction of fluorine atoms from the first gas is large, the supply amount of the first processing gas in the first gas chamber 45 can be more than the supply amount of the second processing gas in the second gas chamber 46. In the manner, the flow rate adjustment units F1 and F2 perform flow rate control of the first process gas and the second process gas.

Further, when the number of introduction of fluorine atoms from the second gas is large, the amount of supply of the first processing gas in the first gas chamber 45 can be made smaller than the amount of supply of the second processing gas in the second gas chamber 46. The flow rate adjustment of the first process gas and the second process gas is performed by the flow rate adjustment units F1 and F2.

In this case, the mixing ratio of the first gas and the second gas of the first processing gas is adjusted by the flow rate adjusting units F6 and F7, and the mixing ratio of the first gas and the second gas of the second processing gas is adjusted by the flow rate. Department F9. In F10, the supply amounts of the first processing gas and the second processing gas to the first gas chamber 45 and the second gas chamber 46, which are adjusted as described above, are controlled by the flow rate adjusting units F1 and F2, respectively.

In addition, when the first gas having a carbon number of 2 or less and the second gas having a carbon number of 3 or more are mixed, the supply amounts of the first gas and the second gas to the first gas chamber 45 and the second gas chamber 46 can be controlled, and In terms of the supply amount of the first gas, the central region is larger than the peripheral region of the gas supply surface, and the peripheral region is larger than the central region of the gas supply surface in terms of the supply amount of the second gas.

Specifically, for example, when CF ₄ gas is used for the first gas and C ₄ F ₈ gas is used for the second gas, C ₄ F ₈ gas and CF ₄ gas are supplied to the first gas chamber 45 at flow rates of 2 sccm and 10 sccm, respectively. The C ₄ F ₈ gas and the CF ₄ gas were supplied to the second gas chamber 46 at a flow rate of 4 sccm and 5 sccm, respectively. In this way, in the central region of the gas supply surface, the ratio of the first gas in the processing gas is larger than that in the peripheral region, and the mixing ratio of the second gas to the first gas is small, and in the peripheral region, the first in the processing gas The ratio of the 2 gas is larger than that of the central region, and the mixing ratio of the second gas to the first gas is large. Therefore, in terms of the first gas, the supply amount of fluorine atoms is larger in the central region of the gas supply surface than in the peripheral region, and the supply of fluorine atoms in the peripheral region of the gas supply surface is related to the second gas. The amount is more than the central area.

In this case, the amount of supply of the first gas to the first gas chamber 45 is performed by the flow rate adjusting unit F1 or the flow rate adjusting unit F6, and regarding the supply amount of the first gas to the second gas chamber 46, This is performed by the flow rate adjustment unit F2 or the flow rate adjustment unit F9. In addition, the supply amount of the second gas to the first gas chamber 45 is performed by the flow rate adjustment unit F1 or the flow rate adjustment unit F7, and the supply amount of the second gas to the second gas chamber 46 is utilized. The flow rate adjustment unit F2 or the flow rate adjustment unit F10 performs the flow rate adjustment unit F2. In this case, the flow rate adjustment unit provided between the first gas supply source 61, the second gas supply source 62, and the first gas chamber 45 or the first gas supply source 64 and the second gas supply source 65 is provided in this example. The flow rate adjustment unit between the second gas chambers 46 and the second gas chamber 46 may be one.

When the first gas having a carbon number of 2 or less and the second gas having a carbon number of 3 or more are mixed in this manner, when the amount of the processing gas supplied to the first gas chamber 45 and the second gas chamber 46 is the same, the first gas can be set to The ratio of the gas to the processing gas is larger in the central region of the gas supply surface than in the peripheral region, and the ratio of the second gas to the processing gas is more in the peripheral region than in the central region of the gas supply surface.

In addition, when the first gas having a carbon number of 2 or less and the second gas having a carbon number of 3 or more are mixed, the first gas to the first gas chamber 45 and the second gas chamber 46 can be controlled to be supplied with the same amount of supply. The supply amount of the gas 2 is larger in the peripheral region than in the central region of the gas supply surface, and the amount of supply to the second gas chamber 46 is more than that in the first gas chamber 45. In the first example, the gas mixing chamber 45 is supplied 2sccm C ₄ F ₈ gas ratio, is supplied to 10sccm mixing ratio of CF ₄ gas, the second gas mixture supplied to the chamber 46 is the ratio of C ₄ 4sccm F ₈ gas was supplied to CF ₄ gas at a mixing ratio of 10 sccm.

At this time, the flow rates of the processing gases to the first gas chamber 45 and the second gas chamber 46 can be set to be the same, and the ratio of the first gas to the processing gas is the same between the first gas chamber 45 and the second gas chamber 46. The ratio of the second gas to the processing gas is larger in the peripheral region than in the central region of the gas supply surface.

Further, it is also possible to control the supply of the second gas to the first gas chamber 45 and the second gas chamber 46 by the same supply amount, and the supply amount of the first gas is larger in the central region than in the peripheral region of the gas supply surface. The amount of supply to the first gas chamber 45 is more than that of the second gas chamber 46. In the first example, the gas mixing chamber 45 is supplied 2sccm C ₄ F ₈ gas ratio, is supplied to 10sccm mixing ratio of CF ₄ gas, the second gas mixture supplied to the chamber 46 is the ratio of C ₄ 2sccm F ₈ gas was supplied to CF ₄ gas at a mixing ratio of 5 sccm.

At this time, the flow rates of the processing gases to the first gas chamber 45 and the second gas chamber 46 may be set to be the same, and the ratio of the second gas to the processing gas may be between the first gas chamber 45 and the second gas chamber 46. Similarly, the ratio of the first gas to the processing gas is larger in the central region than in the peripheral region of the gas supply surface.

In this manner, in the central region of the gas supply surface, the mixing ratio of the second gas to the first gas is small, and in the peripheral region, the mixing ratio of the second gas to the first gas is large, so that the first gas can be controlled. In the central region of the gas supply surface, the amount of fluorine atoms supplied is larger than that of the peripheral region. Regarding the second gas, the amount of fluorine atoms supplied in the peripheral region of the gas supply surface is larger than that of the central region.

In this case, the amount of supply of the first gas to the first gas chamber 45 is also performed by the flow rate adjusting unit F1 or the flow rate adjusting unit F6, and the amount of supply of the first gas to the second gas chamber 46 is related. It is performed by the flow rate adjustment unit F2 or the flow rate adjustment unit F9, and the supply amount of the second gas to the first gas chamber 45 is performed by the flow rate adjustment unit F1 or the flow rate adjustment unit F7, and the second Since the supply amount of the gas to the second gas chamber 46 is performed by the flow rate adjustment unit F2 or the flow rate adjustment unit F10, the first gas supply source 61, the second gas supply source 62, and the first gas chamber 45 are provided. There may be one flow rate adjustment unit or one flow rate adjustment unit provided between the first gas supply source 64, the second gas supply source 65, and the second gas chamber 46.

Further, in the present invention, when the total number of halogen atoms supplied from the first gas is larger than the total number of halogen atoms supplied from the second gas, fluorine per unit area of the gas supply surface can be used per unit time. The total number of atoms is set in a larger amount in the central region than in the peripheral region, and the amount of the processing gas or the supply amount of the processing gas is set. In this case, the first gas and the second gas are supplied in the central region of the gas supply surface. There are more fluorine atoms than the surrounding area.

At this time, when the total number of halogen atoms supplied from the first gas is smaller than the total number of halogen atoms supplied from the second gas, the total number of fluorine atoms per unit time of the gas supply surface can be The composition of the processing gas or the supply amount of the processing gas is set in a manner in which the peripheral region is larger than the central region. In this case, the amount of fluorine atoms supplied from the first gas and the second gas in the peripheral region of the gas supply surface is required. More than the central area.

In such a method, the supply amount of the CF-based gas to the central region of the gas supply surface is larger than the peripheral region, or the supply amount to the peripheral region is larger than the central region, in accordance with the carbon number of the CF-based gas. Therefore, it is clear from the examples described later that the in-plane uniformity of the etching characteristics such as the etching rate, the upper CD or the bottom CD, the etching residual film, the etching depth, the hole shape, and the like can be ensured.

At this time, it is determined in advance whether or not a large number of halogen atoms are supplied to the central region and the peripheral region of the gas supply surface in accordance with the number of carbon atoms in the CF-based gas. Therefore, the central region of the gas supply surface of the processing gas is determined. The parameter range in the supply flow rate in the peripheral region, the composition of the processing gas supplied to the central region and the peripheral region of the gas supply surface, and the like, is reduced in advance, and the conditions can be easily proposed.

[Examples]

Next, an evaluation method relating to the present invention will be described. When the inventors of the present invention obtained various kinds of data and used a CF-based gas as the main etching gas, it was found that the first gas having a carbon number of 2 or less was supplied to the central region of the gas supply surface. The amount of etching in the surface is higher than that in the peripheral region, and the in-plane uniformity of the etching property such as the etching rate or the processed size after etching is increased. On the other hand, in the case of the second gas having a carbon number of 3 or more, the peripheral region of the gas supply surface is made. The amount of supply is greater than that of the central region to improve the in-plane uniformity of the above etching characteristics.

First, an experimental example will be described regarding the mechanism for explaining the present invention.

4 is a view showing that the CF-based gas is a C ₄ F ₈ gas, and in the plasma etching apparatus described above, the processing gas supplied to the first gas chamber 45 (the central region of the gas supply surface) is supplied and supplied to Simulation of gas flow velocity distribution in the vicinity of the surface of the wafer W when the flow rate of the processing gas in the second gas chamber 46 (the peripheral region of the gas supply surface) is changed to the supply amount of the CF-based gas in the central region and the peripheral region of the gas supply surface result. In Fig. 4, the vertical axis represents the gas flow rate, the horizontal axis represents the distance from the center of the wafer, and the two-dotted dotted line represents the flow ratio of the central region (C) of the gas supply surface of the processing gas to the peripheral region (E) (C/ E) is 3/7, and the solid line indicates that the flow rate ratio C/E is 5/5, and the one-dotted line indicates that the flow rate ratio C/E is 7/3. In addition, when the flow rate ratio C/E is 3/7, it means that a processing gas having a flow rate of 3/10 of the total process gas flow rate is supplied in the central region of the gas supply surface, and the total process gas flow rate is supplied in the peripheral region. /10 flow of processing gas.

As a result, when the processing gas is supplied in the central region of the gas supply surface more than the peripheral region, the gas flow rate is the largest, and when the peripheral region is supplied more than the central region, the gas flow rate is the smallest. Here, since the degree of acceleration of the gas flow rate is large when the supply in the central region is large and the supply in the peripheral region is large, it is estimated that the gas rapidly flows from the center of the wafer W to the periphery.

On the other hand, when the supply amount is large in the peripheral region, the gas flow velocity is small in the central region of the wafer W, and the gas flow velocity is rapidly increased in the vicinity of the periphery. Therefore, it is estimated that the gas is trapped in the central region. In this central area, there are many molecules with a long residence time.

Here, when thinking about a CF-based gas having a small number of carbon atoms of 2 or less, the ratio of F/C becomes large, so the etching effect is large, and the in-plane uniformity of the degree of etching progress is the residence time of the gas. Around. Therefore, when the supply amount is large in the peripheral region, the gas residence time in the central region is prolonged, so that the etching progresses more than the peripheral region, and the in-plane uniformity is deteriorated. On the other hand, when the supply in the center region is large, since the gas rapidly flows from the center of the wafer W to the periphery, the gas residence time is easily uniform in the wafer W surface, and the in-plane uniformity of the degree of etching progresses. Will be easy to agree. Further, in the case of a CF-based gas having a large number of carbon atoms of 3 or more, since the ratio of F/C is small, the polymerization is large, and the distribution of the active species is more in-plane than the retention time of the gas. Uniformity works.

Therefore, as shown in FIG. 5, it is assumed that the CF-based gas is C ₄ F ₈ gas, and in the plasma etching apparatus described above, the processing gas supplied to the central region of the gas supply surface and the processing gas supplied to the peripheral region are changed. The flow rate is a simulation of the pressure distribution near the surface of the wafer W. In FIG. 5, the vertical axis is pressure, the horizontal axis is the distance from the center of the wafer, the two-dotted line indicates that the flow rate ratio C/E is 3/7, and the solid line indicates that the flow rate ratio C/E is 5/5. The one-dotted line indicates that the above flow rate ratio C/E is 7/3.

As a result, when more processing gas is supplied to the peripheral region of the gas supply surface than the central region, the pressure distribution is most uniform in the plane of the wafer W. Here, the fact that the pressure distribution is uniform means that the molecular density of the processing gas is uniform, and the density of the active species is uniform in the plane of the wafer W. As described above, when the CF-based gas having a carbon number of 3 or more is supplied in a large amount in the peripheral region than in the central region, the active species are likely to be uniformly present in the surface of the wafer W, whereby the in-plane uniformity of etching is improved.

Further, in order to prove this, C ₅ F ₈ gas was used as the CF-based gas, and Ar gas and O ₂ gas were used as the diluent gas, respectively, and the plasma etching apparatus shown in Fig. 1 was used under the following processing conditions. The plasma of the processing gas is used to form a film forming process on the bare cell (Bare Silicon) by changing the flow rate of the processing gas to the central region of the gas supply surface and the flow rate to the peripheral region, and measuring the in-plane uniformity of the film forming speed at this moment. Sex.

<Processing conditions>. Flow ratio of C ₅ F ₈ gas, Ar gas, O ₂ gas; C ₅ F ₈ : Ar: O ₂ = 15:380: 19 sccm. Process pressure; 1.995Pa (15mTorr). Process temperature; 20 ° C. Frequency and power of the first high frequency power source 61; 60 MHz, 2170 W. Frequency and power of the second high-frequency power source 65; 2MHz, 0W

The result is shown in Fig. 6. In Fig. 6, the vertical axis indicates the film formation speed, the horizontal axis indicates the distance from the center of the wafer, and □ indicates that the flow rate ratio C/E of the processing gas is 7/3, and ○ indicates the flow rate ratio C/ E is 5/5, ■ means that the above flow ratio is C/E of 3/7. Therefore, when the flow rate ratio C/E is 3/7, it is confirmed that the film formation rate is most uniform in the plane of the wafer W, and when the supply amount to the peripheral region is more than the center region, the pressure distribution is Uniform, the density of the active species will be uniform across the surface of the wafer W.

Next, various embodiments will be listed below.

(Example 1)

The premixed CF-based gas is a process gas using CHF ₃ gas and a diluent gas using Ar gas and N ₂ gas, and then introduced into the plasma etching apparatus shown in FIG. 1 and changed to the gas supply surface under the following processing conditions. The amount of supply in the central region and the amount of supply to the peripheral region, and etching treatment of the photoresist film (formed on the entire surface of the wafer W without pattern formation) formed on the wafer W, by performing the LIF (Laser Excitation Fluorescence) Measurement The in-plane uniformity of the wafer W at the current CF density and CF ₂ density was measured. Here, the flow rate ratio C/E of the process gas is 0/10, 3/7, 5/5, 7/3, and 10/0. Further, the above-described flow rate ratio C/E of 0/10 means that only the processing gas is supplied to the peripheral region of the gas supply surface.

<Processing conditions>. Flow ratio of CHF ₃ gas, Ar gas, N ₂ gas; CHF ₃ : Ar: N ₂ = 40: 1000: 80 sccm. Process pressure; 6.65Pa (50mTorr). Frequency and power of the first high frequency power source 61; 60 MHz, 1200 W. Frequency and power of the second high-frequency power source 65; 2MHz, 1700W

As a result, Fig. 7(a) shows the in-plane uniformity of the CF density, and Fig. 7(b) shows the in-plane uniformity of the CF ₂ density. In Fig. 7, the vertical axis indicates the CF density (CF ₂ density), the horizontal axis indicates the distance from the center of the wafer, and ▲ indicates that the flow rate ratio C/E is 0/10, and ■ indicates the flow rate ratio C/. E is 3/7, ○ means that the flow rate ratio C/E is 5/5, □ means that the flow rate ratio C/E is 7/3, and Δ means that the flow rate ratio C/E is 10/0.

From this result, it was confirmed that both the CF density and the CF ₂ density were uniform in the in-plane of the wafer when the flow rate in the central region of the gas supply surface of the first gas chamber 45 was larger than when the flow rate in the peripheral region was large. When the flow rate in the peripheral region is large, the CF density in the central region of the wafer W is high, but the peripheral region is low. As described above, it is estimated that gas retention is formed in the central region of the wafer W. On the other hand, when the flow rate in the central region is large, the density in the central region of the wafer W is low and is substantially uniform in the plane of the wafer W, whereby the in-plane uniformity of the flow velocity distribution of the gas is high. From this, it is estimated that the CF density and the like are uniform in the plane of the wafer W.

When the first gas having a carbon number of 2 or less has a large flow rate in the central region, the active species of the CF-based gas, that is, the active species of CF or CF ₂ are uniformly formed in the plane of the wafer W, thereby presumably The progress of the etching will be uniform in the plane of the wafer W. Further, the inventors of the present invention also attempted the same experiment as the CHF ₃ gas for the C ₄ F ₈ gas. However, since the measured value of the LIF is small and the reliability is low, the measurement data is not described.

(Example 2)

The premixed CF-based gas is a process gas using CHF ₃ gas and a diluent gas using Ar gas and N ₂ gas, and then introduced into the plasma etching apparatus shown in FIG. 1 to change the gas of the processing gas under the following processing conditions. The flow rate of the central region of the supply surface and the flow rate of the peripheral region are used to etch the film to be etched (SiO ₂ film) formed on the wafer W, and the residual film of the photoresist, the etching depth, the upper CD, and The in-plane uniformity of the bending position was evaluated. At this time, the flow ratio of the central region to the peripheral region of the gas supply surface of the processing gas is when the flow rate ratio C/E is 1/9, 5/5, and 9/1.

Here, in Fig. 8(a), 71 is an SiO film to be etched, and 72 is a photoresist film formed on the surface of the SiOC film. The photoresist residual film is at a distance A, and the etching depth is a distance B. The position is a distance C formed at the most expanded portion of the hole (concave portion) 73 of the SiOC film, and the upper portion CD means the diameter D formed on the upper side of the hole (concave portion) 73 of the SiOC film.

Then, the in-plane uniformity is such that the etched film is taken up by the cross-sectional SEM, and the distances A, B, C, and the diameter D of the center portion and the peripheral portion of the wafer W are obtained from the photograph. The smaller the difference between the center portion and the peripheral portion, the better the in-plane uniformity. Here, the center portion of the wafer W is the rotation center of the wafer W, and the peripheral portion of the wafer W means a position inside the outer edge of the wafer W by 5 mm. The photoresist residual film, the etching depth, the bending position, the definition of the upper CD, the method of obtaining the data, and the method of evaluating the in-plane uniformity based on the data difference between the center portion and the peripheral portion of the wafer W are as follows. The same is true in the embodiment.

<Processing conditions>. Flow ratio of CHF ₃ gas, Ar gas, N ₂ gas; CHF ₃ : Ar: N ₂ = 40: 1000: 80 sccm. Process pressure; 6.65Pa (50mTorr). Frequency and power of the first high frequency power source 61; 60 MHz, 1200 W. Frequency and power of the second high-frequency power source 65; 2MHz, 1700W

The result is shown in Fig. 8(b). In the case of CHF ₃ gas, the difference (absolute value) between the center portion and the peripheral portion of the photoresist residual film, the etching depth, the upper CD, and the bent position of the wafer is smaller when the flow rate in the central region is larger than that in the peripheral region. According to this embodiment, it is also understood that when the CF-based gas having a carbon number of 2 or less has a large flow rate in the central region, the etching proceeds in the wafer W plane, the photoresist residual film, the etching depth, and the upper CD. The in-plane uniformity of the etching characteristics at the bending position is good.

(Example 3)

The premixed CF-based gas is a process gas using CHF ₃ gas and a diluent gas using Ar gas, N ₂ gas, and O ₂ gas, and then introduced into the plasma etching apparatus shown in FIG. 1 to be changed under the following processing conditions. The flow rate of the gas to the central region of the gas supply surface and the flow rate to the peripheral region, the etching process of the etched film (SiOCH film) formed on the wafer W, and the upper portion CD formed by etching at this point The in-plane uniformity and the in-plane uniformity of the etching depth were evaluated.

<Processing conditions>. Process pressure; 6.65Pa (50mTorr). Frequency and power of the first high frequency power source 61; 60 Hz, 1500 W. Frequency and power of the second high-frequency power source 65; 2MHz, 2800W

As a result, the in-plane uniformity of the in-plane uniformity and the etching depth of the upper CD are shown in Fig. 9 (a) and Fig. 9 (b), respectively. In Fig. 9(a), the vertical axis represents the absolute value of the data difference between the central portion and the peripheral portion of the upper CD, and the vertical axis in Fig. 9(b) is the absolute value of the data difference between the central portion and the peripheral portion of the etching depth. Further, in Figs. 9(a) and 9(b), the horizontal axis represents the flow ratio C/E of the central region of the processing gas and the peripheral region. For example, when the flow ratio is 50%, it means that the flow ratio C/E is At 5/5, when 90% means that the above flow ratio is C/E is 9/1.

According to these results, it was confirmed that when the supply of the central portion of the gas supply surface is large, the upper CD and the etching depth are small in the data difference between the central portion and the peripheral portion of the wafer W, and the in-plane uniformity is good. As a result, the first gas having a carbon number of 2 or less is also understood. When the flow rate in the central region is large, the degree of etching proceeds in the plane of the wafer W.

(Example 4)

The CF-based gas is preliminarily mixed with a CH ₂ F ₂ gas, and the diluent gas is a process gas using O ₂ gas, and then introduced into the plasma etching apparatus shown in FIG. 1 to change the processing gas to the crystal under the following processing conditions. The flow rate of the central region of the circle W and the flow rate to the peripheral region, and etching treatment of the film to be etched (the laminated film of the SiO film and the SiOCH film) formed on the wafer W, and the residual film of the photoresist at this moment, The in-plane uniformity of the upper CD, the bottom CD, and the Recess was evaluated. At this time, the flow ratio of the central region of the processing gas to the peripheral region is when the flow rate ratio C/E is 1/9, 5/5, and 9/1.

<Processing conditions>. Flow ratio of CH ₂ F ₂ gas, O ₂ gas; CH ₂ F ₂ : O ₂ = 40: 20 sccm. Process pressure; 7.98Pa (60mTorr). Frequency and power of the first high-frequency power source 61; 60MHz, 700W. Frequency and power of the second high-frequency power source 65; 2MHz, 300W

Here, the bottom CD means the aperture E formed on the bottom side of the hole 73 of the film (SiOC film) 71 to be etched in FIG. 8(a), and Recess means the amount of etching of the underlayer film of the film to be etched. Further, regarding the in-plane uniformity, for example, the etched film is taken by the cross-sectional SEM, and the data of the center portion and the peripheral portion of the wafer W are obtained for each item based on the photograph, and the difference between the two is obtained. By this, the smaller the difference, the better the in-plane uniformity. The definition of the bottom CD or Recess, the method of obtaining the data, and the method of evaluating the in-plane uniformity based on the data difference between the center portion and the peripheral portion of the wafer w are also the same in the following embodiments.

As a result, as shown in FIG. 10, when the flow rate ratio C/E is 9/1, the photoresist residual film, the upper CD, the bottom CD, and the Recess are data differences between the center portion and the peripheral portion (the difference is an absolute value). It is small and the in-plane uniformity is the best. From this result, it is also possible to understand the first gas having a carbon number of 2 or less. When the flow rate in the central region is large, the degree of etching proceeds in the plane of the wafer W.

(Example 5)

The CF-based gas is preliminarily mixed with a C ₄ F ₈ gas, and the diluent gas is a processing gas using Ar gas and N ₂ gas, and then introduced into the plasma etching apparatus shown in FIG. 1 to change the processing gas under the following processing conditions. An etched film formed on the wafer W is applied to the flow rate in the central region of the gas supply surface and the flow rate in the peripheral region (TEOS having a thickness of 50 nm and an anti-reflection film having a thickness of 100 nm are laminated on the SiOC film (BARC) The etching process was evaluated for the shape of the hole formed at this moment. The flow rate of the process gas to the central region of the wafer W and the flow rate to the peripheral region are when the flow rate ratio C/E is 1/9, 5/5, and 9/1.

<Processing conditions>. Flow ratio of C ₄ F ₈ gas, Ar gas, N ₂ gas; C ₄ F ₈ : Ar: N ₂ = 5: 1000: 150 sccm. Process pressure; 6.65Pa (50mTorr). Frequency and power of the first high frequency power source 61; 60 MHz, 500 W. Frequency and power of the second high-frequency power source 65; 2MHz, 2000W

Here, the hole shape is an extension of the side wall outer surface 74 of the hole 73 shown in FIG. 11(a) and the surface constituting the bottom of the hole with respect to the hole formed in the center portion of the wafer W and the hole formed in the peripheral portion. The angle formed between 75, that is, the inclination angle θ, is determined by taking the difference between the two. The smaller the difference, the better the in-plane uniformity of the pore shape.

The result is shown in Fig. 11(b). In Fig. 11(b), the vertical axis indicates the inclination angle θ, the horizontal axis indicates the position on the wafer, ◇ indicates that the flow rate ratio C/E is 1/9, and □ indicates the flow rate ratio C/E. When it is 5/5, Δ means that the above flow ratio C/E is 9/1. From this, it was confirmed that the difference between the center portion and the peripheral portion of the wafer W at the inclination angle θ was the smallest when the flow rate ratio C/E was 1/9, and the in-plane uniformity of the hole shape was good. From this result, it is understood that the second gas having a carbon number of 3 or more has a hole shape that coincides in the plane of the wafer W when the flow rate in the peripheral region is large.

(Example 6)

The premixed CF-based gas is a two-type gas using C ₄ F ₈ gas and CF ₄ gas, and the diluent gas is a processing gas that is not used, and then introduced into the plasma etching apparatus shown in FIG. 1 and changed under the following processing conditions. The etching flow of the etching film (SiOCH film) formed on the wafer W to the supply flow rate of the gas in the central region of the gas supply surface and the supply flow rate to the peripheral region, and the surface of the upper portion CD at this moment The above-described evaluation was performed by internal uniformity.

<Processing conditions>. Flow ratio of C ₄ F ₈ gas, CF ₄ gas; C ₄ F ₈ : CF ₄ gas = 5:200 sccm. Frequency and power of the first high frequency power source 61; 60 MHz. Frequency and power of the second high frequency power supply 65; 2 MHz

The result is shown in FIG. In FIG. 12, the vertical axis represents the absolute value of the upper CD difference, and the horizontal axis represents the flow ratio C/E of the central region of the processing gas and the peripheral region. From this, it was confirmed that the data difference between the center portion and the peripheral portion of the upper CD was the smallest when the flow rate ratio C/E=7/3, and the in-plane uniformity of the upper CD was good.

In this example, the flow ratio of the C ₄ F ₈ gas to the CF ₄ gas is C ₄ F ₈ : CF ₄ = 5 sccm: 200 sccm, and the fluorine amount supplied by the CF ₄ gas is higher than that supplied by the C ₄ F ₈ gas. In this case, it can be understood that the in-plane uniformity of the upper CD can be ensured when the flow rate to the central region of the gas supply surface is increased by the CF ₄ gas.

(Example 7)

The premixed CF-based gas is a two-type gas using C ₄ F ₈ gas and CF ₄ gas, and the diluent gas is a processing gas using N ₂ gas and O ₂ gas, and then introduced into the processing chamber, and after performing the first etching treatment, Then, the CF-based gas is preliminarily mixed with a C ₄ F ₈ gas, and the diluent gas is a process gas using Ar gas and N ₂ gas, and then introduced into the processing chamber, and when the second etching treatment is performed, the in-plane of the upper CD and the bottom CD are in-plane. Uniformity, using the techniques described, for evaluation. At this time, the plasma etching apparatus shown in FIG. 1 is used to change the supply flow rate of the processing gas to the central region of the gas supply surface of the wafer W and the supply flow rate to the peripheral region under the following processing conditions. An etching process of an etched film on the wafer W (a TEOS having a thickness of 50 nm and a reflection preventing film (BARC) having a thickness of 65 nm is laminated on the SiOCH film). With respect to the flow rate ratio C/E, in the first etching process and the second etching process, when the flow rate ratio C/E is 5:5, and in the first etching process, the flow rate ratio C/E is 9:1. In the second etching treatment, the flow rate ratio C/E was 1:9, and the evaluation was performed.

<Processing Conditions of First Etching Treatment>. Flow ratio of C ₄ F ₈ gas, CF ₄ gas, N ₂ gas, O ₂ gas; C ₄ F ₈ : CF ₄ : N ₂ : O ₂ = 6: 15: 120: 10 sccm process pressure; 6.65 Pa (50 mTorr) . Frequency and power of the first high-frequency power source 61; 60MHz, 800W. Frequency and power of the second high-frequency power source 65; 2MHz, 1400W

<Processing Conditions of Second Etching Treatment>. Flow ratio of C ₄ F ₈ gas, Ar gas, N ₂ gas; C ₄ F ₈ : Ar: N ₂ = 8: 50: 1000 sccm. Process pressure; 3.325Pa (25mTor r). Frequency and power of the first high frequency power source 61; 60 MHz, 1000 W. Frequency and power of the second high-frequency power source 65; 2MHz, 3000W

The result is shown in Fig. 12. Thereby, the upper CD can be confirmed, and the data difference (absolute value) between the center portion and the peripheral portion of the wafer W of the bottom CD is the first etching process, and the central region is supplied in a large amount, and in the second etching process, the peripheral region is supplied in a large amount. In the case of small, the in-plane uniformity of the above CD is good.

By changing the type of the CF-based gas and continuing the first etching treatment and the second etching treatment, the supply flow rate of the processing gas to the central region and the peripheral region can be controlled in accordance with the carbon number of each CF-based gas. The flow rate is supplied to thereby perform an etching process having high in-plane uniformity.

At this moment, in the first etching treatment, the flow ratio of the C ₄ F ₈ gas to the CF ₄ gas is C ₄ F ₈ : CF ₄ = 6 sccm: 15 sccm, and the fluorine amount supplied by the CF ₄ gas is higher than that by the C ₄ F _{Since the} gas supplied by the gas ₈ has a large number of fluorines, it can be understood that when the flow rate to the central region is increased by the CF ₄ gas, the upper CD or the bottom CD can be aligned in the plane of the wafer W. Further, in the second etching treatment, since the C ₄ F ₈ gas is used, it can be understood that when the flow rate in the peripheral region is increased, the upper CD or the bottom CD can be aligned in the wafer W surface.

(Example 8)

The etching process of the film to be formed formed on the wafer W was performed under the same etching conditions as in Example 7, and the in-plane was performed by CD-SEM (electron microscope in which the wafer W was observed from above without destruction). Evaluation of CD distribution. As a result, Fig. 14(a) shows that in the first etching process, the flow rate ratio C/E is 9:1, and in the second etching process, when the flow rate ratio C/E is 1:9, Fig. 14(b) This means that both the first and second etching processes are when the flow rate ratio C/E is 5:5. Further, in FIG. 14, the vertical axis represents the CD shift value, the horizontal axis represents the position on the wafer, ◇ is the data indicating the X axis, and ○ is the data indicating the Y axis. The CD shift value of this example means the difference between the aperture diameter of the mask and the aperture diameter after etching.

As a result, it was confirmed that the CD shift value is the X-axis data and the Y-axis data are all supplied in the first etching process in the center region, and are small in the case where the second etching process is performed in the peripheral region. The uniformity of the in-plane CD distribution is high.

(Example 9)

When a CF gas is mixed in advance, a C ₅ F ₈ gas is used, and a diluent gas is a process gas using an Ar gas or an O ₂ gas, and then introduced into a processing chamber to perform an etching process, and an etching rate, a photoresist selectivity, and light are used. The uniformity of the resist residual film and the etching depth was evaluated. At this time, the plasma etching apparatus shown in FIG. 1 is used to form the supply flow rate of the processing gas to the central region of the gas supply surface of the wafer W and the supply flow rate to the peripheral region under the following processing conditions. Etching treatment of the photoresist on the wafer W. At this time, the etching rate was evaluated when the supply flow rate of the processing gas to the central region was 208 sccm, the supply flow rate to the peripheral region was 208 sccm, and the supply flow rate to the central region was 208 sccm, and the supply flow rate to the peripheral region was 312 sccm. Wait. Here, the etching selectivity is calculated based on the amount of etching of the SiO ₂ film/the amount of reduction of the photoresist film thickness, and the in-plane uniformity of the etching rate and the selectivity of the photoresist is, for example, by the cross-sectional SEM. The etched film is taken, and the etch rate and the selectivity of the photoresist are determined in the center portion and the peripheral portion of the wafer W based on the photograph, and the difference between the center portion and the peripheral portion is smaller, and the in-plane The better the uniformity.

<Processing conditions>. Flow ratio of C ₅ F ₈ gas, Ar gas, O ₂ gas; C ₅ F ₈ : Ar: O ₂ = 16:380: 20 sccm. Process pressure; 3.325Pa (25mTor r). Frequency and power of the first high frequency power source 61; 60 MHz, 1000 W. Frequency and power of the second high-frequency power source 65; 2MHz, 3000W

The result is shown in Fig. 15. Therefore, it can be confirmed that when the supply flow rate to the peripheral region is large more than the supply flow rate to the central region of the gas supply surface, the etching rate, the photoresist selectivity, the photoresist residual film, and the etching depth are on the wafer W. The difference between the center portion and the peripheral portion is small, and the in-plane uniformity is good.

Further, in this example, the supply flow rate of the peripheral region is not changed, but the supply flow rate of the peripheral region is changed. However, if the supply flow rate to the central region is the same, the flow rate of the wafer W is changed even if the supply flow rate to the peripheral region is changed. The etch characteristics of the center will not change. Therefore, it can be understood that by setting the total flow rate of the processing gas, the flow rate of the supply flow rate to the central region, and the flow rate of the supply flow rate to the peripheral region, the flow rate of the peripheral region is increased without changing the flow rate of the central region, and maintenance is maintained. In the case of the etching property of the center region, the etching characteristics of the peripheral region are changed, and the in-plane uniformity of the etching property can be improved.

(Embodiment 10)

When the CF gas is a C ₄ F ₈ gas and the dilution gas is an etching process using CO gas, N ₂ gas, and O ₂ gas, the in-plane uniformity of the CD shift value is evaluated. At this time, the plasma etching apparatus shown in FIG. 1 is used to change the supply flow rate of the processing gas to the central region of the wafer W and the supply flow rate to the peripheral region under the following processing conditions to form the wafer W. Etching treatment of an etched film (SiOC film). Here, the evaluation is performed when the flow rate ratio C/E is 2/4, 2/2, and 2/6.

<Processing conditions>. Process pressure; 6.65Pa (50mTor r). Frequency and power of the first high-frequency power source 61; 60MHz, 800W. Frequency and power of the second high-frequency power source 65; 2MHz, 1400W

The result is shown in Fig. 16. Whereby it was confirmed that, by varying the supply flow rate of C ₄ F ₈ gas towards the peripheral area, the peripheral area of the wafer W, CD shift value can change dramatically, by C ₄ F ₈ gas to the peripheral region of the Since the supply flow rate is larger than the central area, the in-plane uniformity of the above CD shift is improved.

Thereby, it can be understood that the etching process with high in-plane uniformity can be performed by changing the mixing ratio of the first gas and the second gas supplied to the processing gas in the central region and the peripheral region.

(Example 11)

The CF-based gas is a gas of two types using CHF ₃ gas and CF ₄ gas, and the diluent gas is subjected to a first etching treatment using Ar gas and N ₂ gas, and then the CF gas is a C ₄ F ₈ gas, and the diluent gas is used. When the second etching treatment was performed using Ar gas and N ₂ gas, the in-plane uniformity of the upper CD described above was evaluated. At this point, the plasma etching apparatus shown in FIG. 1 is introduced by mixing the processing gas at a specific flow rate in advance, and the supply flow rate of the processing gas to the central region of the wafer W and the peripheral region are changed under the following processing conditions. The flow rate is supplied to perform etching processing of the photoresist formed on the wafer W.

<Processing Conditions of First Etching Treatment>. Flow ratio of CHF ₃ gas, CF ₄ gas, Ar gas, N ₂ gas; CHF ₃ : CF ₄ : Ar: N ₂ = 15: 15: 500: 80 sccm. Process pressure; 6.65Pa (50mTor r). Frequency and power of the first high-frequency power source 61; 60MHz, 800W. Frequency and power of the second high-frequency power source 65; 2MHz, 1700W

<Processing Conditions of Second Etching Treatment>. Flow ratio of C ₄ F ₈ gas, Ar gas, N ₂ gas; C ₄ F ₈ : Ar: N ₂ = 7: 950: 120 sccm. Process pressure; 6.65Pa (50mTor r). Frequency and power of the first high frequency power source 61; 60 MHz, 1200 W. Frequency and power of the second high-frequency power source 65; 2MHz, 1700W

Further, the supply flow rate in the central region and the peripheral region is such that the flow rate ratio C/E = 50/50 in the first etching process and the second etching process, and in the first etching process, the flow rate ratio C/E is 95:5. In the second etching treatment, the flow rate ratio C/E was 5:95, and the evaluation was performed.

The result is shown in FIG. In this case, in the case of the upper CD, the central region is supplied in a large amount in the first etching process, and when the peripheral region is supplied in the second etching process, the difference between the central portion and the peripheral portion is small. Good in-plane uniformity.

In the first etching process, it is confirmed that the processing gas in which the CHF ₃ gas, the CF ₄ gas, the Ar gas, and the N ₂ gas are mixed is used, so that the first gas having a carbon number of 2 or less is supplied. The supply amount of the processing gas in the central region is increased. In the second etching treatment, since the processing gas in which the C ₄ F ₈ gas, the Ar gas, and the N ₂ gas are mixed is used, the _second gas having a carbon number of 3 or more is supplied. The supply amount of the processing gas to the peripheral region is increased, thereby ensuring good etching characteristics.

(Embodiment 12)

When the CF-based gas is a C ₄ F ₈ gas and a CF ₄ gas, and the diluent gas is an N ₂ gas or an O ₂ gas, and the gas is mixed in advance, and the etching process is performed by the mixed processing gas, the etching rate is used. In-plane uniformity is used for evaluation. At this time, the plasma etching apparatus shown in FIG. 1 is used to form the wafer W on the supply flow rate of the processing gas to the central region of the gas supply surface and the supply flow rate to the peripheral region under the following processing conditions. Etching treatment of the photoresist.

<Processing conditions>. Flow ratio of C ₄ F ₈ gas, CF ₄ gas, N ₂ gas, O ₂ gas; C ₄ F ₈ : CF ₄ : N ₂ : O ₂ = 6: 15: 120: 10 sccm. Process pressure; 6.65Pa (50mTor r). Frequency and power of the first high-frequency power source 61; 60MHz, 800W. Frequency and power of the second high-frequency power source 65; 2MHz, 1400W

Further, the supply flow rate in the center area and the peripheral area is evaluated in the case where the flow rate ratio C/E = 50/50 and the flow rate ratio C/E is 90:10.

The result is shown in FIG. From this, it was confirmed that in terms of the etching rate, when the supply in the central region is large, the difference between the center and the periphery is small, and the in-plane uniformity of the etching rate is good.

This case, the mixed gas is supplied to the first gas and second gas, CF ₄ gas by the number of fluorine than the number of fluorine supplied by C ₄ F ₈ gas supplied is large, as long as the CF ₄ gas is supplied in accordance with In this case, the supply flow rate of the processing gas to the central region and the peripheral region may be controlled.

As described above, in the present invention, the substrate may be a glass substrate or the like used for a flat display panel, such as an LCD glass substrate or a PDP substrate, in addition to the semiconductor wafer W. Further, in the plasma etching apparatus used in the present invention, in addition to the parallel plate type plasma etching apparatus, a magnetic field RIE method, an ICP method, an ECR method, a spiral wave (Helicon Wave) plasma method, or the like can be used.

W‧‧‧Semiconductor Wafer

1‧‧‧Processing room

2‧‧‧ mounting table

3‧‧‧Electrical chuck

4‧‧‧Gas Supply Department

45‧‧‧1st gas introduction room

46‧‧‧2nd gas introduction room

51‧‧‧1st gas introduction path

52. . . Second gas introduction path

54,61,64. . . First gas supply source

55,62,65. . . Second gas supply source

6. . . Control department

F1~F11. . . Flow adjustment department

Fig. 1 is a plan view showing an embodiment of a plasma etching apparatus of the present invention.

Fig. 2 is a configuration diagram showing a gas supply system of the plasma etching apparatus.

3 is a configuration diagram showing a gas supply system of another example of the plasma etching apparatus.

4 is a characteristic diagram showing a simulation result of in-plane uniformity of a gas flow rate.

Fig. 5 is a characteristic diagram showing a simulation result of in-plane uniformity of pressure.

Fig. 6 is a characteristic diagram showing in-plane uniformity of film formation speed.

Fig. 7 is a characteristic diagram showing in-plane uniformity of CF density and CF ₂ density in Example 1.

8 is a characteristic diagram showing in-plane uniformity of a photoresist residual film, an etching depth, an upper CD, and a bending position in Example 2. FIG.

Fig. 9 is a characteristic diagram showing the in-plane uniformity of the absolute value of the in-plane uniformity and the etching depth difference of the absolute value of the upper CD difference in the third embodiment.

Fig. 10 is a characteristic diagram showing the in-plane uniformity of the photoresist residual film, the upper CD, the bottom CD, and the Recess of Example 4.

Fig. 11 is a characteristic diagram showing the in-plane uniformity of the inclination angle θ of the fifth embodiment.

Fig. 12 is a characteristic diagram showing the in-plane uniformity of the absolute value of the upper CD difference in the sixth embodiment.

Fig. 13 is a characteristic diagram showing the in-plane uniformity of the upper CD and the bottom CD of the seventh embodiment.

Fig. 14 is a characteristic diagram showing the in-plane uniformity of the CD shift value of the eighth embodiment.

Fig. 15 is a characteristic diagram showing the in-plane uniformity of the uniformity of the etching rate, the photoresist selectivity, the photoresist residual film, and the depth in Example 9.

Fig. 16 is a characteristic diagram showing the in-plane uniformity of the CD shift value of the tenth embodiment.

Fig. 17 is a characteristic diagram showing the in-plane uniformity of the CD of the eleventh embodiment.

Fig. 18 is a characteristic diagram showing the in-plane uniformity of the etching rate in Example 12.

1. . . Processing room

2. . . Mounting table

4. . . Upper electrode

6. . . Control department

45. . . First gas introduction chamber

46. . . Second gas introduction chamber

51. . . First gas introduction path

52. . . . Second gas introduction path

53. . . Process gas supply system

54. . . First gas supply source

55. . . Second gas supply source

56. . . Dilution gas supply

57. . . Supply road

F1~F5. . . Flow adjustment department

W. . . Semiconductor wafer

Claims (13)

An etching method is a method of etching an etching film of a substrate by a gas supply portion and a processing gas, wherein the gas supply portion is from a central region facing a central region of the substrate and a peripheral region facing the substrate In the peripheral region, the processing gas is supplied to the substrate independently, and the processing gas system includes a first gas containing carbon having a carbon number of 2 or less in one molecule and a halogen, and is characterized in that each of the gas supply surfaces of the gas supply unit is The supply amount of the first gas per unit time per unit area is such that the etching gas of the substrate is etched while supplying the processing gas from the gas supply unit so that the central region is larger than the peripheral region. An etching method is a method of etching an etching film of a substrate by a gas supply portion and a processing gas, wherein the gas supply portion is from a central region facing a central region of the substrate and a peripheral region facing the substrate In the peripheral region, the processing gas is supplied to the substrate independently, and the processing gas system includes a second gas containing carbon and halogen having 3 or more carbon atoms in one molecule, and is characterized in that each of the gas supply surfaces of the gas supply unit is The supply amount of the second gas per unit time per unit area is such that the etching gas is etched on the substrate while supplying the processing gas from the gas supply unit so that the peripheral region is larger than the central region. An etching method is a method of etching an etching film of a substrate by a gas supply portion and a processing gas, wherein the gas supply portion is from a central region facing a central region of the substrate and a peripheral region facing the substrate The processing gas is supplied to the substrate independently in the peripheral region, and the processing gas system mixes the first gas containing carbon and halogen having 2 or less carbon atoms in one molecule, and the carbon and halogen containing 3 or more carbon atoms in one molecule. The second gas is characterized in that the mixing ratio of the second gas to the first gas is the same in the central region and the peripheral region of the gas supply portion, and the total number of halogen atoms supplied by the first gas is higher than that of the second gas. When the total number of the halogen atoms to be supplied is large, the supply amount of the mixed gas per unit time per unit area of the gas supply surface of the gas supply unit is larger from the central region than the peripheral region. When the processing gas is supplied, when the total number of halogen atoms supplied from the first gas is smaller than the total number of halogen atoms supplied from the second gas, the gas supply is The supply amount of the mixed gas per unit time per unit area of the gas supply surface is such that the peripheral gas is supplied from the gas supply unit while the peripheral gas is supplied from the gas supply unit. The film is etched. An etching method according to claim 3, wherein the supply amount of the mixed gas of the first gas and the second gas is such that the central region is more than the peripheral region, or the peripheral region is more than the central region. The process of supplying the process gas from the gas supply unit is to adjust the process gas. At least one of the flow rate of the body and the dilution rate of the processing gas of the diluent gas is performed. An etching method is a method of etching an etching film of a substrate by a gas supply portion and a processing gas, wherein the gas supply portion is from a central region facing a central region of the substrate and a peripheral region facing the substrate The processing gas is supplied to the substrate independently in the peripheral region, and the processing gas system mixes the first gas containing carbon and halogen having 2 or less carbon atoms in one molecule, and the carbon and halogen containing 3 or more carbon atoms in one molecule. The second gas is characterized in that a first processing gas in which the first gas and the second gas are mixed by the first mixing ratio is supplied in a central region of the gas supply unit, and a second mixing is supplied in a peripheral region of the gas supply unit. When the total amount of halogen atoms supplied from the first gas is larger than the total number of halogen atoms supplied from the second gas, the gas supply unit is related to the second processing gas in which the first gas and the second gas are mixed. The supply amount of the mixed gas per unit time per unit area of the gas supply surface is such that the supply amount of the first processing gas is larger than the supply amount of the second processing gas. The supply unit supplies the processing gas, and when the total number of halogen atoms supplied from the first gas is smaller than the total number of halogen atoms supplied from the second gas, the unit area of the gas supply surface of the gas supply unit is The supply amount of the mixed gas per unit time is supplied from the gas supply unit so that the supply amount of the first processing gas is smaller than the supply amount of the second processing gas. The gas is etched while etching the substrate. An etching method is a method of etching an etching film of a substrate by a gas supply portion and a processing gas, wherein the gas supply portion is from a central region facing a central region of the substrate and a peripheral region facing the substrate The processing gas is supplied to the substrate independently in the peripheral region, and the processing gas system mixes the first gas containing carbon and halogen having 2 or less carbon atoms in one molecule, and the carbon and halogen containing 3 or more carbon atoms in one molecule. The second gas is characterized in that the supply amount of the first gas per unit time per unit area of the gas supply surface of the gas supply unit is larger than the peripheral area, and the gas supply unit is provided. In the supply of the processing gas, the supply amount of the second gas per unit time per unit area of the gas supply surface of the gas supply unit is supplied from the gas supply unit so that the peripheral area is larger than the central area. The film is etched while etching the film on the substrate. An etching method is a method of etching an etching film of a substrate by a gas supply portion and a processing gas, wherein the gas supply portion is from a central region facing a central region of the substrate and a peripheral region facing the substrate The processing gas is supplied to the substrate independently in the peripheral region, and the processing gas system mixes the first gas containing carbon and halogen having 2 or less carbon atoms in one molecule, and the carbon and halogen containing 3 or more carbon atoms in one molecule. The second gas is characterized in that each unit of the gas supply surface of the gas supply unit is the same when the supply amount of the first gas is the same in the central region and the peripheral region of the gas supply unit. The supply amount of the second gas per unit time of the area is such that the peripheral gas is supplied from the gas supply unit so that the peripheral region is larger than the central region, and the second gas is supplied from the gas supply portion in the central region and the peripheral region. When the supply amount is the same, the supply amount of the first gas per unit time per unit area of the gas supply surface of the gas supply unit is supplied from the gas supply unit so that the central area is larger than the peripheral area. The film is etched while etching the film on the substrate. The etching method according to any one of the preceding claims, wherein the supply amount of the first gas is supplied from a gas supply unit such that a central region is larger than a peripheral region. The process of processing the gas is performed by adjusting at least one of the flow rate of the first gas and the dilution rate of the first gas of the diluent gas. The etching method according to any one of claims 2, 6 or 7, wherein the supply amount of the second gas is supplied from the gas supply unit so that the peripheral area is larger than the central area. The process of treating the gas is performed by adjusting at least one of the flow rate of the second gas and the dilution rate of the second gas of the diluent gas. An etching method is a method of etching an etching film of a substrate by a gas supply portion and a processing gas, wherein the gas supply portion is from a central region facing a central region of the substrate and a peripheral region facing the substrate The processing gas is supplied to the substrate independently in the peripheral region, and the processing gas system mixes the first gas containing carbon and halogen having 2 or less carbon atoms in one molecule, and the carbon and halogen containing 3 or more carbon atoms in one molecule. The second gas is characterized by: When the total number of halogen atoms supplied from the first gas is larger than the total number of halogen atoms supplied from the second gas, the halogen atom per unit area of the gas supply surface of the gas supply unit is used. The total number of the central regions is larger than the peripheral region, and the composition and amount of the processing gas supplied from the gas supply unit are set, and the total number of halogen atoms supplied from the first gas is higher than that supplied by the second gas. When the total number of the halogen atoms is small, the total number of halogen atoms per unit time per unit area of the gas supply surface of the gas supply unit is set to be larger from the central region than the central region. The composition and amount of the process gas. The etching method according to any one of claims 1 to 3, wherein the first gas system is at least CH ₂ F ₂ gas, CHF ₃ gas, CF ₄ gas, C ₂ F ₆ Any of the gases. The etching method according to any one of claims 2 to 7, wherein the second gas system is at least C ₃ F ₈ gas, C ₄ F ₈ gas, C ₄ F ₆ gas, C ₅ Any of the F ₈ gases. An etching apparatus comprising: a processing container in which a mounting table on which a substrate is placed is provided; and a gas supply unit that is disposed inside the processing container so as to face the mounting table; And a gas supply surface provided on a surface facing the mounting table for the substrate placed on the mounting table from a central region facing the central region of the substrate and a peripheral region facing the peripheral region of the substrate Providing a process gas containing carbon and halogen independently; means for adjusting the pressure inside the processing container; a means for generating a plasma inside the processing container; means for adjusting a flow rate of the processing gas supplied to the gas supply portion; and a control portion capable of implementing the first to tenth patent claims The method of engineering controls the above-mentioned means to plasmaize the processing gas, and etch the film to be etched by the plasma.