JPH0729893A - Lep electrode supporting mechanism - Google Patents

Abstract

PURPOSE:To provide a mechanism whereby a local discharge is prevented from being generated between the inner wall of a chamber and an LEP electrode, and the distance between the LEP electrode and a substrate can be changed without the changing of the volume of the chamber and without the necessity of an expensive spacer having a larger diameter, in the dry etching equipment wherein a plasma is generated by the acceleration of electrons through a rotating electric field. CONSTITUTION:In an LEP electrode supporting mechanism, the heights of an upper cover 11 and a bottom plate of a chamber 1 are not variable, but an LEP electrode 2 is suspended from above the upper cover 11 by an electrode suspending bar 12. A small spacer is provided around the electrode suspending bar 12, and is fastened to the upper cover 11. Since the spacer is not fastened to any wall, no concentration of a discharge is generated. By changing the height of the spacer, the distance between the LEP electrode and a wafer can be changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting an upper electrode in a dry etching apparatus which uses a high frequency rotating electric field to convert gas into plasma. Advances in photolithography technology and etching technology are indispensable in order to further advance the density of semiconductor integrated circuits.

[0002]

2. Description of the Related Art Dry etching is a method in which a gas is used as a plasma to accelerate the gas, which is then applied to a substrate to remove a semiconductor portion on the substrate which is not covered with a resist by a physical chemical action. It is desirable to etch the portion not covered by the resist as vertically as possible. Wet etching which is used in other fields isotropically proceeds. On the other hand, that the etching progresses only perpendicularly to the resist surface is called anisotropic etching. Dry etching has excellent anisotropy. The properties described above can be expressed by the high anisotropy.

When the semiconductor portion is simply removed by the physical impact force of ions, an inert gas may be used as the gas. This is simply called ion etching. However, this is rarely used because of its slow etching rate.

The most widely used etching method at present is reactive ion etching (RIE). The semiconductor is removed by a chemical reaction using a halogen gas as the gas. This uses a parallel plate electrode or the like to apply a high frequency to halogen gas or the like to generate plasma, which etches the semiconductor portion. Current RIE generates plasma in a fairly low vacuum. This is because plasma is easier to stand in a low vacuum. When the degree of vacuum is low (the pressure is high), the mean free path of ions is short and the ions are easily scattered. When the ions are scattered, the proportion of ion beams obliquely incident on the resist surface increases. In order to cut a semiconductor vertically in a fine resist hole, the incident direction of ions must be perpendicular to the substrate surface. For this purpose, the mean free path of the ions may be lengthened to reduce the scattering probability. If the scattering probability is low, only ion beams that fly in a direction perpendicular to the resist surface are incident on the wafer. Therefore, the etching anisotropy becomes high. Therefore, it is necessary to increase the degree of vacuum. However, if the degree of vacuum is increased, high frequency discharge becomes difficult to occur. If a high frequency is simply applied to the parallel plate electrodes, plasma will not stand unless the pressure is considerably high. Then, the etching rate becomes low. This was a problem.

In order to solve the problem of generating high density plasma in a high vacuum, a magnetron reactive ion etching method and an ECR etching method have been developed. In the magnetron reactive ion etching method, for example, four electromagnets are provided around a conventional parallel plate electrode, and the phase of the exciting current of the electromagnets is changed by 2π / 4 to generate a rotating magnetic field in the chamber. It is intended to raise the ionization efficiency by causing the cyclotron motion of electrons.

In the ECR etching method, for example, a coil is provided outside the chamber and a DC magnetic field is generated in the vertical direction.
2.45 GHz microwave is externally introduced into the chamber. Electrons undergo cyclotron motion due to the DC magnetic field, but if the period of the electrons is the same as the period of the microwaves, the electrons resonate and absorb the microwaves. Since the electrons having kinetic energy collide with gas atoms and molecules to make them ions, the ionization rate is also improved.

However, in the magnetron reactive ion etching method, the density of the rotating magnetic field is not spatially uniform. Therefore, the plasma density becomes spatially non-uniform. In the ECR etching method, since the magnetic field is also spatially non-uniform, the plasma density becomes spatially non-uniform. Since the plasma density is non-uniform, the etching rate is not uniform within the wafer surface.
Naturally, the etching depth becomes non-uniform on the wafer surface. For example, if such an etching method using a magnetic field is applied to the MOSLSI process, the gate oxide film is deteriorated.

In this way, a method has been proposed in which electron motion is stimulated by a magnetic field to maintain discharge even in a high vacuum and increase the ionization rate. However, all of them have a drawback that the plasma density becomes non-uniform due to the spatial non-uniformity of the magnetic field.
Since the semiconductor portion is removed by the action of plasma or radicals, if the plasma is not spatially uniform, the etching rate will also be spatially non-uniform. If a large-diameter wafer is to be etched, the etching depth within the plane of the wafer will be significantly non-uniform. Therefore, these methods are not suitable for etching large-diameter wafers.

Therefore, a dry etching method using a rotating electric field was invented by the present inventors. Japanese Patent Laid-Open No. 4-268
No. 727, Japanese Patent Application Laid-Open No. 4-290226, Japanese Patent Application No. 2-40
No. 2319 and Japanese Patent Application No. 4-215820. A high frequency voltage having a phase difference of 2π / n is applied to the n electrodes to generate a rotating electric field in the chamber, which causes electrons to rotate around the vertical axis to be accelerated and hit gas atoms into plasma. To etch the substrate.

This is one in which upper and lower parallel plate electrodes and n LEP electrodes are provided in the chamber. The substrate to be etched is placed on the lower parallel plate electrode. The LEP electrodes are provided so as to face each other so as to be rotationally symmetrical. The upper and lower parallel plate electrodes generate an alternating electric field in the vertical direction. The lateral LEP electrodes generate a rotating electric field in the horizontal direction. The high frequency applied to the upper and lower parallel plate electrodes is, for example, 50M.
Hz, the high frequency for the horizontal rotating electric field is 300 MHz.

As mentioned earlier, reactive ion etching utilizes only parallel plate electrodes. Compared to this, the number of LEP electrodes provided on the intermediate side increases. Since the magnetron reactive ion etching method is composed of upper and lower parallel plate electrodes and electromagnets on the side of the middle, it means that the electromagnets are replaced by electrodes. Since there is a technology that can generate plasma even in a high vacuum by energizing electrons with a magnetic field, the idea of energizing electron motion using a fluctuating electric field rather than just parallel plate electrodes will soon emerge. It seems to be but not so. This is because it was thought that the magnetic field would enter the inside of the high density plasma but not the electric field. Plasma is a collection of charged particles. It was thought that in the presence of high-density plasma, the space charge was localized and the electric field did not reach inside. That is, the outer charge shields the electric field and does not reach the inner part. A thin cathode wire can be easily bent by an electric field, but a large current cathode wire is difficult to control by an electric field. Therefore, no one but the present inventor has attempted to utilize the fluctuating electric field to elevate electron motion to generate plasma even in a high vacuum.

The present inventor named the etching method utilizing such a rotating electric field the LEP method. The entire etching system is called the LEP system, and the laterally symmetrical electrodes are LE
I decided to call it the P electrode. It is not a generic name. It may be referred to as LEP or Lissajous plasma etching apparatus. A Lissajous figure is a locus of two-dimensional motion that combines simple vibrations in mutually perpendicular directions. It has this name because it can be drawn with a machine designed by LISSAJOUS in France.

X = Acos ωt, y = Bcos (Ωt + δ) (1)

Is synthesized. That is, it is the locus of points (x, y). Various figures can be obtained by the difference between the angular frequencies ω and Ω, the value of δ, and the amplitudes A and B. Obtain various shapes such as circles, ellipses, and straight lines. An ellipse, even when the angular frequencies are equal,
It may be a straight line or a circle.

Initially, the present invention is directed to two sets of electrodes facing each other,
That is, the four electrodes were set at 90 degrees apart, and high-frequency waves having the same voltage amplitude but different phases by 90 degrees were applied to create a rotating electric field. In the above equation, ω = Ω, A = B, and δ = 90 degrees. Then the electric field becomes circular with Ω.

E _X = Acos ωt, E _Y = Acos (ωt + π / 4) (2)

As described above, when voltages having a 90-degree phase difference are applied to the two pairs of electrodes facing each other in the horizontal direction, a rotating electric field can be formed. The electrode arrangement is the direction to create an orthogonal electric field,
It was named Lissajous because the phase was different. In reality, the electric field is either circular or elliptical.
It does not mean drawing a complicated general Lissajous figure.

However, the present inventor goes one step further, and it should be possible to form a rotating electric field even when a high frequency wave having a phase difference of 2π / n is applied to n electrodes placed at rotationally symmetrical positions. I noticed. Not limited to n = 4, n = 3
However, a rotating electric field can be created even when n = 6. The n electrodes are installed at rotationally symmetric positions so as to form central angles of 2π / n degrees. That is, the position of the j-th electrode (X _j , Y _j )
Is

X _j = H cos (Ωt + 2πj / n) (3)

Y _j = H sin (Ωt + 2πj / n) (4)

The voltage V _j of the _j -th electrode is V _j = Kcos (Ωt + 2πj / n) (5)

It is given as follows. Then, the electric field at the center surrounded by the electrodes is zero. However, away from the center, an electric field proportional to the distance is generated. This electric field is xy
It lies on the surface and rotates at an angular velocity of Ω.

That is, generally, n electrodes are provided and 2π
When a high frequency voltage having a phase difference of / n is applied, a rotating electric field proportional to the distance from the center can be formed. Therefore, we decided to use Lissajous plasma etching to include such cases. It is called LEP electrode whether it is three or five. The electrodes are sometimes called Lissajous electrodes to distinguish them from the device.

[0024]

FIG. 4 is a schematic configuration diagram of a Lissajous plasma etching apparatus. Several LEP electrodes 2 are provided in the chamber 1 in the vertical direction. This is an equivalent electrode plate provided in a rotationally symmetrical position. The lower electrode 3 is located below, and the wafer 4 is mounted thereon.
A resist is applied on the surface of the wafer 4 and an appropriate resist pattern is formed by photolithography. Since the lower electrode 3 generates heat, it is cooled.

FIG. 5 shows a conventional example (JP-A-4-268727).
And Japanese Patent Laid-Open No. 4-290226). FIG. 6 is a front view of the same thing. This is an example using three LEP electrodes 2. The inner wall 5 of the chamber 1 is formed in a hexagonal shape so that the electrodes can be attached stably and easily. The LEP electrode 2 is an insulator 6 on three of the six surfaces.
It is attached via. The chamber is at ground potential and LE
The P electrode 2 needs to be insulated because a high frequency is applied. The wall of the chamber has three holes 7 through which a code 8 for supplying a voltage to the LEP electrode 2 passes. The chamber 1 is thus an irregularly shaped container and must be made of metal as it needs to be perforated. With quartz, such complicated processing cannot be performed and it is not possible to support the electrode on the side surface. As long as it is metal, the electric potential must not float, so it is grounded. Between the chamber 1 and the base chamber 9 there are several ring-shaped spacers 10. The upper part of the chamber 1 is closed by an upper lid 11. A semiconductor substrate (wafer) 4 to be etched is placed on the lower electrode 3. The lower electrode 3 is fixed to the base chamber 9. The LEP electrode 2 is fixed to the inner wall 5 of the chamber. Therefore, the distance between the substrate (wafer) 4 and the LEP electrode 2 is constant.

There are two problems to be solved. This will be explained in order. One is the problem of discharge between the electrode and the chamber. Although the electrode and the chamber are insulated via the insulator 6, there is only a space between the chamber and the electrode at the end of the electrode. The length of this space is equal to the thickness of the insulator 6. Since the insulator is thin, the length of the space is short. Then, a discharge Q is generated between the end of the electrode and the chamber 1. When such discharge concentration occurs, the plasma density increases only in this vicinity. Therefore, the plasma becomes denser only around the wafer 4. Therefore, the side edge of the wafer is etched deeper. It is necessary to prevent such a local discharge from occurring between the electrode and the chamber. For this purpose, the thickness of the insulator should be increased. However, doing so reduces the effective volume within the chamber. In addition, since the electrode is heated by plasma, if it is desired to cool it, it will be difficult to cool it because it is blocked by an insulator. Thus, the anisotropic discharge between the electrode end and the chamber is the first problem.

As described above, in the structure shown in FIG. 5, the distance between the substrate and the LEP electrode is constant. The vertical distance W between the substrate and the LEP electrode is an important parameter for efficient plasma etching. The closer the LEP electrode is to the substrate, the higher the plasma utilization efficiency. However, the further the distance between the LEP electrode and the substrate, the more uniform the plasma density. If you want to etch a large diameter wafer, a uniform plasma density must be formed over a wide area.
It means that it is better that the electrode and the substrate are separated.
The optimum vertical distance between the electrode and the substrate also depends on the material of the substrate. Therefore, even if you want to change the distance W depending on the material, the conventional LEP
This is difficult with the device. This is because the height of the electrode with respect to the chamber does not change because the electrode is fixed to the side surface of the chamber. It is not possible to remove the electrode and replace it at another position on the inner wall of the chamber.

If the distance W is to be changed, several large-diameter ring-shaped spacers 10 must be inserted between the chamber 1 and the base chamber 9 as shown in FIG. That is, the distance W can be changed by changing the distance between the base chamber and the chamber only by sandwiching the spacer. This spacer 10 must have the same shape as the chamber 1. It is a large member and the spacer 10
The cost of the device is increased by the amount of. In addition, when the spacer is inserted, the volume of the chamber changes. Since the input power and the etching gas are set to the optimum values for a chamber of a certain volume, the power and gas must be changed when the volume changes. If the chamber volume is changed because the distance between the electrode and the substrate is changed, other parameters must be changed, and other conditions are kept constant to obtain the optimum value for the distance between the substrate and the electrode. I can't. As shown in FIG.
However, the above device has a drawback in that the distance between the electrode and the substrate cannot be freely changed and adjusted. It is the fixedness of the electrode substrate distance.
This is another problem.

The first object is to provide a mechanism that prevents local discharge from occurring between the inner wall of the chamber and the electrode. It is a second object of the present invention to provide a mechanism capable of changing the distance between the LEP electrode and the substrate without changing the chamber volume. A third object is to provide a mechanism that can change the distance between the electrode and the substrate without requiring an expensive spacer having a large diameter.

[0030]

The dry etching apparatus of the present invention does not attach an electrode to the inner wall surface of the chamber,
The LEP electrode is suspended from above the chamber with a support rod. An insulating layer of 100 μm or more is formed on the inner wall of the chamber. Since the electrode can be separated from the chamber, local discharge between the chamber and the electrode can be prevented. Not only the hanging, but also the lifting mechanism of the LEP electrode.
Holes for the number of electrodes are made in the upper lid of the chamber of the LEP device, a hanging rod is inserted into this hole, and it is installed at an arbitrary height with respect to the upper lid using a small spacer. Fix the LEP electrode. Since a vacuum must be maintained inside the chamber, the suspension rod is surrounded by a cylindrical spacer or insulating ring. Since the upper lid is fixed to the chamber and the chamber is fixed to the base chamber, the volume inside the chamber hardly changes even when the LEP electrode is moved up and down.

There are various methods for forming the insulating layer on the inner wall of the chamber. Alumina having a thickness of 100 μm or more is sprayed on the inner wall of the metal chamber. A ceramic cover with a thickness of 100 μm or more is adhered to the inner wall of the metal chamber. A quartz cover with a thickness of 100 μm or more is adhered to the inner wall of the metal chamber. The side of the chamber is a quartz tube. If the lid is made of metal, the electrodes can be suspended. It is possible to hermetically bond the quartz and metal lids at the flange. A Teflon film having a thickness of 100 μm or more is formed on the inner wall of the metal chamber.

[0032]

The LEP electrode is not fixed to the inner surface of the chamber as in the prior art, but is hung from the upper lid by a hanging rod and the LEP electrode is fixed to the lower end thereof. The height of the electrode can be adjusted by moving the suspension rod up and down. This allows the electrode and chamber to be separated. There is an insulating layer on the inner wall of the chamber, and because the chamber and the electrode are separated from each other and the insulating layer acts, discharge concentration does not occur between the electrode and the chamber. This is one action. Another effect is that the distance W between the substrate and the electrode can be changed by raising and lowering the suspension rod. Since the suspension rod is moved up and down, the volume in the chamber does not change. Therefore, it is not necessary to readjust parameters such as input power and supply gas flow rate. Of course, in order to maintain the vacuum in the chamber, the suspension rod must be surrounded hermetically by a cylindrical spacer or an insulating cylinder. The reason why the electrode is surrounded by the insulating cylinder is that the electrode needs to be insulated from the chamber upper lid.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional plan view of an apparatus having a LEP electrode lifting mechanism of the present invention, FIG. 2 is a plan view showing the appearance of the same, and FIG. 3 is a sectional view of a LEP electrode suspension mechanism.
The outer shell of the device comprises a cylindrical chamber 1, an upper lid 11, and a base.
It consists of a subchamber 9. There is no such thing as a spacer between these. The distance between the chamber 1 and the base chamber 9 is constant. The LEP electrode is not fixed to the side surface of the chamber but is suspended from the upper lid 11 by the suspension rod 12. Therefore, the inner surface of the chamber 1 does not have a hexagonal shape but has a simple cylindrical shape. The skeleton of the chamber can be made of stainless steel or aluminum. An insulating layer (alumina, ceramic, quartz, etc.) is 100μ on the inner wall
It is formed with a thickness of m or more. The LEP electrode is Al,
The surface is anodized. LE in this example
The distance between the P electrode and the inner wall of the chamber is 5 cm.

The height of the suspension bar 12 with respect to the upper lid 11 can be freely adjusted. The upper lid 11 has through holes 13 for the number n of LEP electrodes. The upper lid 11 is fixed to the chamber flange 14 with bolts 15. The hanging rod 12 penetrates the through hole 13 at the lower side and is in the internal space of the chamber 1. The hanging rod 12 is a rod having a circular cross section, and a flat surface is formed in one direction of the lower end thereof, and the LEP electrode 2 is fixed thereto by a bolt 16.

The upper half of the hanging rod 12 is an insulating ring 1.
7, surrounded by a spacer 18 and the like. These inner diameters are substantially equal to the inner diameter of the through hole 13. A wide hanging flange 19 is formed above the hanging rod 12. The hanging flange 19 holds the spacer 18 from above. Passages 30 and 31 through which cooling water or a coolant passes for cooling are formed inside the suspension rod. The refrigerant is introduced through the upper inlet 32 and discharged through the outlet 33. Since the LEP electrode generates heat due to plasma, cooling water or a coolant is passed to cool it. The electrode temperature is kept at a constant optimum temperature.

A hole 20 is formed in a part of the hanging flange 19, and a stud 21 and an insulating collar 22 are inserted into the hole 20. The lower end of the stud 21 is screwed into the screw hole 23 on the upper surface of the upper lid 11. A washer 24 is fitted on the upper end of the stud 21, and is fastened by a nut 25. The stud 21 allows the suspension flange 19
Is pushed downwards. However, since the insulating ring 17 and the spacer 18 are provided between the hanging flange 19 and the upper lid 11, the height of the hanging flange is determined by this. Teflon or FRP is used for the insulating color and insulating ring.

By replacing the spacer 18, the height of the electrode can be adjusted. Spacers and insulating rings 17 are required for the number of electrodes. The inside of the chamber must be evacuated. Therefore, the upper lid 11 and the insulating ring 17
An O-ring 26 is provided between the insulating ring 17 and the spacer 1.
An O-ring 27 is inserted between the spacers 8 and an O-ring 28 is inserted between the spacer 18 and the upper lid flange 19. An O-ring 29 is provided between the chamber flange 14 and the upper lid 11.

The height of the LEP electrode can be adjusted by the height of the spacer. The position of the electrode is lowest when there is no spacer. The position of the electrode becomes higher as the width of the spacer is increased. To change the spacer, do the following: Remove the top lid from the chamber. Turn the top lid over so that the hanging bar is facing up. Remove the LEP electrode from the hanging rod. Loosen the nut on the mounting stud of the hanging flange. Remove the hanging flange from the top lid. The spacer is released, so change the spacer.
Place the spacer of the desired height on the insulation ring except for the previous spacer. Now assemble in reverse order.

One embodiment will be described. Using the apparatus of the present invention (FIG. 1) and the apparatus of the comparative example (FIG. 5), n ⁺ -polySi was etched while changing the pressure. The device of the present invention suspends the electrodes from above. In the comparative example, the LEP electrode is fixed to the inner wall. The pressure fluctuation range is 0.
It is 5 Pa to 5 Pa. The etching gas was Cl ₂ and the flow rate was 80 sccm. The high frequency applied to the lower electrode 3 was 13.56 MHz, and the power was 80 W. The upper LEP electrode has a phase difference of 120 degrees.
A high frequency of 4.24 MHz was applied. The power is 70W. Under such conditions, etching was performed by the apparatus of the present invention and the apparatus of the comparative example, and the non-uniformity of etching in the wafer surface was examined. This result is shown in FIG. The vertical axis represents the non-uniformity, which is the distribution of the etching depth divided by the average value. If this is small, it means that the uniformity is high. If this is high, it means that it is not uniform.

According to the present invention, etching uniformity is extremely excellent against pressure fluctuation. Pressure P = 1Pa
And the non-uniformity is 2%. The non-uniformity increases as the pressure increases, but it is 4% at 2 Pa and 8% at 3 Pa. 3 Pa
When it becomes above, non-uniformity does not increase and it is 8% even at 5 Pa. Even above this, it will be below 10%. This is because no local discharge occurs between the electrode and the chamber.

In the comparative example, it is 3% at 1 Pa. This is fairly uniform. However, it is unstable and the non-uniformity increases rapidly with pressure fluctuations. It is 6% at 0.5 Pa. Below 1 Pa, the nonuniformity becomes large. Conversely, 3 Pa
At the pressure of 3, the nonuniformity is as high as 34%. If it is higher than this, the nonuniformity is further increased. From this alone, it can be seen that in the case of the comparative example, the instability due to pressure fluctuation is large. An alternating current path is generated between the electrode attached to the side surface and the chamber, and the plasma is excessively densified in the vicinity of the electrode. When the pressure rises, active species increase near this and etching becomes non-uniform. For this reason, if the pressure exceeds 3 Pa, the nonuniformity will increase rapidly.

Further, charge-up damage evaluation using a MOS structure TEG was performed. According to the etching apparatus of the present invention, even a gate oxide film having a thickness of 10 nm cannot be used.
Di was not detected. This is considered to be due to the good plasma uniformity.

[0043]

According to the present invention, in the Lissajous plasma etching apparatus, the LEP electrode is not directly attached to the wall surface of the chamber, but the electrode is suspended from the lid.
Therefore, the distance between the electrode and the chamber can be widened, and no discharge occurs between the LEP electrode and the chamber. Therefore, the plasma density becomes uniform in a wide range in the chamber. Therefore, the etching rate in the wafer surface becomes uniform. Moreover, since the electrode is suspended from the lid plate, the height of the LEP electrode can be changed. As many spacers as there are electrodes are used, but this is a small spacer. Therefore, the cost of the spacer can be reduced. In addition, the volume inside the chamber does not change as the electrode height changes. Therefore, it is not necessary to change the parameters such as the supply gas flow rate and the input power. It is possible to perform etching under electrode conditions of different heights without changing the etching conditions.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view of a dry etching apparatus including a LEP electrode lifting mechanism according to an embodiment of the present invention.

FIG. 2 is a plan view of a dry etching apparatus including a LEP electrode lifting mechanism according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a portion of a lifting mechanism for LEP electrodes.

FIG. 4 is a schematic configuration diagram of a dry etching apparatus using LEP electrodes.

FIG. 5 is a cross-sectional plan view of LEP dry etching according to a conventional example.

FIG. 6 is a front view of LEP dry etching according to a conventional example.

FIG. 7 shows n ⁺ poly S by the device of the present invention and the device of the comparative example
The graph which shows the pressure dependence of etching nonuniformity at the time of etching i.

[Explanation of symbols]

 1 Chamber 2 LEP Electrode (Upper Electrode) 3 Lower Electrode 4 Wafer 5 Inner Wall 6 Insulator 7 Hole 8 Code 9 Base Chamber 10 Spacer 11 Upper Lid 12 Hanging Rod 13 Through Hole 14 Chamber Flange 15 Bolt 16 Bolt 17 Insulation ring 18 Spacer 19 Hanging flange 20 Hole 21 Stud 22 Insulation collar 23 Screw hole 25 Nut

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tokuhiko Tamaki, 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Mitsuhiro Oguni, 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Ichiro Nakayama 1006 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Masafumi Kubota 1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Noboru Nomura 1006 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (6)

[Claims] 1. A cylindrical chamber having an insulator having a thickness of 100 μm or more on its inner wall surface, a base chamber fixed to the bottom of the chamber, and a chamber having n holes to cover the upper part of the chamber. An upper lid, a lower electrode on which a semiconductor wafer to be placed on the base chamber is to be placed in the chamber, and rotationally symmetrical positions are provided in the chamber so as to face each other.
It is composed of a single LEP electrode, an etching gas is introduced into the chamber, a rotating electric field is generated by a high frequency voltage having different phases applied to the LEP electrode, and the gas is made into plasma,
A LEP electrode supporting mechanism, wherein a LEP electrode is supported from above by a hanging rod fixed to an upper lid via an insulator in a LEP dry etching apparatus adapted to etch a wafer. 2. A cylindrical chamber having an alumina sprayed layer having a thickness of 100 μm or more on its inner wall surface, a base chamber fixed to the bottom of the chamber, and an upper part of the chamber having n holes. An upper lid for covering, and a lower electrode on which a semiconductor wafer placed on the base chamber in the chamber should be placed,
It consists of n LEP electrodes that are provided in rotationally symmetrical positions in the chamber so as to face each other. An etching gas is introduced into the chamber, and a rotating electric field is generated by a high-frequency voltage with different phases applied to the LEP electrodes. An LEP electrode supporting mechanism, wherein a LEP electrode is supported from above by a hanging rod fixed to an upper lid via an insulator in a LEP dry etching apparatus in which a wafer is etched with plasma as plasma. 3. A cylindrical chamber having an inner wall surface fitted with a ceramic cover having a thickness of 100 μm or more, a base chamber fixed to the bottom of the chamber, and an upper portion of the chamber having n holes. The upper lid to be covered, the lower electrode on which the semiconductor wafer placed on the base chamber in the chamber should be placed, and the n LEP electrodes provided in the chamber at rotationally symmetrical positions so as to face each other. In the LEP dry etching apparatus in which an etching gas is introduced into the chamber, a rotating electric field is generated by high-frequency voltages having different phases applied to the LEP electrode, and the gas is used as plasma to etch the wafer, an insulator is provided on the upper lid. An LEP electrode support mechanism, wherein the LEP electrode is supported from above by a suspension rod fixed through the LEP electrode. 4. A cylindrical chamber having an inner wall surface fitted with a quartz cover having a thickness of 100 μm or more, a base chamber fixed to the bottom of the chamber, and an upper part of the chamber having n holes. The upper lid to be covered, the lower electrode on which the semiconductor wafer placed on the base chamber in the chamber should be placed, and the n LEP electrodes provided in the chamber at rotationally symmetrical positions so as to face each other. Then, an etching gas was introduced into the chamber, a rotating electric field was generated by high-frequency voltages having different phases applied to the LEP electrodes, and the gas was used as plasma to etch the LE.
In the P dry etching apparatus, the LEP electrode support mechanism is characterized in that the LEP electrode is supported from above by a hanging rod fixed to the upper lid via an insulator. 5. A cylindrical chamber having an insulator having a thickness of 100 μm or more on its inner wall surface, a base chamber fixed to the bottom of the chamber, and a top of the chamber having n holes. An upper lid, a lower electrode on which a semiconductor wafer to be placed on the base chamber is to be placed in the chamber, and rotationally symmetrical positions are provided in the chamber so as to face each other.
It is composed of a single LEP electrode, an etching gas is introduced into the chamber, a rotating electric field is generated by a high frequency voltage having different phases applied to the LEP electrode, and the gas is made into plasma,
In a LEP dry etching apparatus for etching a wafer, a hanging rod which is to be inserted through a hole in an upper lid to fix a LEP electrode to a lower end, a hanging flange for supporting the hanging rod, and a circumference of each hanging rod. , An insulating ring inserted between the upper lid and the hanging flange, a spacer, a stud for fixing the hanging flange to the upper lid, and an insulating collar for insulating the stud and the hanging flange. A LEP electrode support mechanism, wherein the height of the LEP electrode is changed by inserting spacers of different heights between the flange and the upper lid. 6. A cylindrical chamber having an insulator having a thickness of 100 μm or more on its inner wall surface, a base chamber fixed to the bottom of the chamber, and a top of the chamber having n holes. An upper lid, a lower electrode on which a semiconductor wafer to be placed on the base chamber is to be placed in the chamber, and rotationally symmetrical positions are provided in the chamber so as to face each other.
It is composed of a single LEP electrode, an etching gas is introduced into the chamber, a rotating electric field is generated by a high frequency voltage having different phases applied to the LEP electrode, and the gas is made into plasma,
In a LEP dry etching apparatus for etching a wafer, a hanging rod which is to be inserted through a hole in an upper lid to fix a LEP electrode to a lower end, a hanging flange for supporting the hanging rod, and a circumference of each hanging rod. , An insulating ring inserted between the upper lid and the hanging flange, a spacer, a stud for fixing the hanging flange to the upper lid, and an insulating collar for insulating the stud and the hanging flange. A cooling medium passage is provided inside the rod to cool the LEP electrode, and spacers of different heights are inserted between the hanging flange and the upper lid so that the LEP electrode is cooled.
A LEP electrode support mechanism, characterized in that the height of the EP electrode is changed.