JPH05275399A - Method and device for dry etching - Google Patents

Abstract

PURPOSE:To shape a trench hole sidewall etched into the curve with a curvature of exponential function, being gradually widened outward and smooth, by exciting electric field in both horizontal and vertical direction relative to a wafer surface, and irradiating the wafer surface with ultra-violet ray, to perform etching. CONSTITUTION:A parallel flat plate electrodes 23 and a mesh-like magnet coil 16 are provided in an etching chamber 8 to control negative ion's behavior. Firstly, the parallel flat plate electrodes 23 are provided on both sides of a sample stage 18, and 6V DC is applied between the electrodes to generate an electric field parallel to a wafer 17. When this electric field is generated, the negative ion has the movement speed parallel to the wafer 17. In addition, the coil of mesh-like magnet coil 16 is applied with 50mA, so that a magnetic field is generated on the wafer 17. The uniform circular motion of the negative ion takes place with the magnetic field as its axis, in a horizontal plane of the wafer 17, and the ion collides with the silicon grid of the sidewall in the middle of circular motion, so that side-etching is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device and its apparatus, and more particularly to a dry etching method for forming a trench hole in single crystal silicon and its apparatus.

[0002]

2. Description of the Related Art A semiconductor device is a device formed by finely processing passive and active circuit elements in one substrate in an inseparable state.

In a conventional semiconductor device, silicon dioxide or borosilicate glass (Boro-Phospho Sili) is provided in a trench hole formed in a single crystal silicon substrate.
An element isolation region or a trench capacitor in which an insulator such as a cataly glass (BPSG) or polycrystalline silicon is buried is formed. 7 (a)-(d)
FIG. 11 is a cross-sectional view for explaining a method of forming and burying a trench hole in a conventional semiconductor device. In FIG. 7A, a photoresist 2 is formed as an etching mask for forming a trench hole on the single crystal silicon substrate 1 by using a normal lithography technique and is patterned.

Thereafter, the opening (single crystal silicon exposed portion) is etched using the photoresist 2 as a mask to form a trench hole. Dry etching suitable for fine processing is most often used as an etching means. Among dry etching, a parallel plate electrode of cathode coupling is used and silicon tetrachloride (SiCl ₄ ) and chlorine (C
l ₂ ) mixed gas (mixing ratio Cl ₂ / SiCl ₄ = 10%
Reactive ion etching (RIE: Reacti) for etching the single crystal silicon substrate 1 by the straightness of the ions generated by the high frequency (13.56 MHz) glow discharge.
ve Ion Etching), FIG.
As described above, anisotropic etching with excellent mask transfer accuracy is achieved, and the trench hole 3 having a vertical sidewall is formed.

An ordinary trench hole has an opening width of 1 to 2 μm.
The groove has a depth of about 3 to 10 μm. After forming the trench holes, the photoresist 2 is removed as shown in FIG. After that, as shown in FIG. 7D, silicon dioxide (SiO ₂ ) and BPS are deposited in the trench hole 3.
After the buried material 4 such as G or polycrystalline silicon is formed, the step of forming the trench element isolation region or the trench capacitor cell is completed. As a method of forming the buried substance 4, a chemical vapor deposition method is generally preferred and used.

[0006]

A drawback of such a conventional method of manufacturing a semiconductor device is that an acute corner portion 5 is generated in the opening portion of the trench hole 3. When the trench hole 3 is filled with the filling material 4 using the chemical vapor deposition method, the opening portion of the trench hole 3 is 1 μm to 3 μm.
Since it is extremely narrow as μm and is very deep as 3 μm to 10 μm, that is, because the aspect ratio is large, the reaction gas molecules do not wrap easily and the reaction gas molecules do not easily reach the bottom of the trench hole 3.

As a result, the growth rate of the embedding substance 4 is highest at the acute-angled corner portion 5 and gradually decreases toward the bottom of the trench hole 3 in the depth direction. Therefore, reactive gas molecules cannot penetrate into the trench hole 3 and a void (cavity) 6 is generated in the trench hole 3. The voids 6 generated in the trench holes 3 are likely to become traps of contaminants, and may cause cracks to be generated in the buried substance 4, thus lowering the yield and reliability of the semiconductor device.

An object of the present invention is to provide a dry etching method and an apparatus therefor, which have improved reliability and yield.

[0009]

In order to achieve the above object, the dry etching method according to the present invention causes a microwave and a magnetic field to mutually interfere with each other to cause an electron cyclotron resonance phenomenon to turn a gas into a plasma, and a wafer surface is exposed. This is a dry etching method for etching, in which an electric field is excited in the horizontal direction with respect to the wafer surface, a magnetic field is excited in the vertical direction, and ultraviolet rays are applied to the wafer surface for etching.

A dry etching apparatus for carrying out the dry etching method according to the present invention comprises a parallel plate electrode,
A dry etching apparatus that has a magnet coil and an ultraviolet source, mutually interferes with a microwave and a magnetic field, causes an electron cyclotron resonance phenomenon to turn a gas into plasma, and etches a wafer surface. The magnet coils are placed on both sides of the wafer installed in the etching chamber and excite an electric field in the horizontal direction with respect to the wafer surface.The magnet coils are placed above and below the wafer installed in the etching chamber and introduced into the etching chamber. A magnetic field is excited in the direction perpendicular to the wafer surface, and the ultraviolet ray source irradiates the wafer surface in the etching chamber with ultraviolet rays.

The power supply voltage of the ultraviolet source, the applied voltage of the parallel plate electrodes, and the applied current of the magnet coil are controlled as a function of time.

[0012]

In the present invention, the anion generated when the chlorine trifluoride gas introduced into the etching chamber is photolyzed with ultraviolet rays,
A horizontal electric field is used to provide a moving speed in the horizontal direction. Next, when a magnetic field is applied vertically downward, the negative ions having a moving velocity in the horizontal direction receive the Lorentz force, and as a result, they move uniformly in the horizontal direction with the vertical direction as the axis. The anions, which move in a uniform circular motion, eventually collide vertically with the sidewall of the trench, chemically react with the silicon single crystal lattice, and side etch the sidewall.

[0013]

The present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows an electron cyclotron resonance discharge (Electron Cyclotron) according to the present invention.
on Resonance (hereinafter abbreviated as ECR) is a cross-sectional view showing Example 1 applied to an etching apparatus.

In the figure, the ECR etching apparatus of the present invention comprises an ionization chamber 7 and a cylindrical etching chamber 8, and a microwave oscillator 9 and a microwave waveguide 10 are attached to the ionization chamber 7.

The hydrogen bromide (HBr) gas whose flow rate is controlled from the hydrogen bromide (HBr) cylinder 11 through the mass flow controller 12 is 5 × 1 by the vacuum exhaust pump 13.
It is introduced into the ionization chamber 7 kept at a pressure of 0 ^-1 Pa.

In the ionization chamber 7, a microwave oscillator 9
The microwaves oscillated by and the magnetic field excited by the magnet coil 14 interfere with each other to cause an electron cyclotron resonance phenomenon to efficiently convert hydrogen bromide (HBr) gas into plasma. When a microwave of 2.45 GHz which is an industrial frequency is used, the electron cyclotron resonance condition is satisfied if a magnetic field having a magnetic field density of 875 Gauss is generated. When hydrogen bromide (HBr) introduced into the ionization chamber 7 is turned into plasma, cations (H ⁺ , Br ⁺ ) and anions (B
r ⁻ ) and radical (Br ^* ) electrons.

The electrons generated in the plasma circularly move under the electron cyclotron resonance condition, but the magnetic field obtained from the magnet coil 14 has the maximum intensity in the upper part of the ionization chamber 7, and the lower part of the ionization chamber, that is, the ion extraction electrode 1
In the divergent magnetic field which becomes weaker toward 5, the circular motion electrons are accelerated in the direction of the ion extraction electrode 15 which is the magnetic field divergent direction due to the magnetic field gradient in order to exhibit diamagnetism and perform a spiral motion.

Ion extraction electrode 1 while spiraling
The electrons moving in the direction of 5 accelerate cations in the plasma, that is, protons (H ⁺ ) and bromine ions (Br ⁺ ) in the direction of the ion extracting electrode 15 in order to satisfy the electrically neutral condition, and the electrons themselves A bipolar electric field that slows down the electric field is generated, and an equilibrium state is established.

Positive ions (Br ⁺ ) and protons (H ⁺ ) accelerated vertically downward by the bipolar electric field are introduced into the etching chamber 8 through the ion extracting electrode 15.

A sample stage 18 on which a mesh-shaped magnet coil 16 and a wafer 17 patterned by a general lithography technique are placed is installed in the etching chamber 8 and is introduced through the mesh-shaped magnet coil 16. The positive cations (Br ⁺ ) etch only the exposed silicon portion of the patterned portion of the wafer 17 to form a trench hole. Since protons (H ⁺ ) have a small mass number, they do not participate in the etching of single crystal silicon.

There are two types of mechanisms by which a silicon single crystal is etched by bromine ions (Br ⁺ ). One is a phenomenon in which accelerated bromine ions (Br ⁺ ) physically collide with single crystal silicon to knock out silicon atoms, and etching progresses. The other one is incident bromine ions (Br ⁺ ). Of silicon tetrabromide (SiBr) with a high vapor pressure
₄ ) is formed, and the molecule sublimates and desorbs to promote etching. In the actual etching, both mechanisms are in progress at the same time, but since the bromine ion (Br ⁺ ) is accelerated by the bipolar electric field in the ionization chamber 7, it has an extremely high vertical direction, so that the trench is formed. The side wall of the hole is never sputtered or chemically reacted with the side wall to cause a reaction.

As a result, if the trench hole is formed by using the above-mentioned ECR dry etching apparatus, it becomes possible to perform anisotropic etching in which the side wall has a vertical shape and there is no side etching. The techniques up to this point are known.
The features of the ECR dry etching apparatus of the present invention and the specific effects obtained by the apparatus will be described below.

In the present invention, a mass flow controller 1 is installed in the etching chamber 8 from a chlorine trifluoride (ClF ₃ ) cylinder.
A chlorine trifluoride (ClF ₃ ) gas having a controlled flow rate is introduced via 2. The introduction flow rate is about 5 cm ³ / min, and the inside of the etching chamber 8 is 1 × 10 by using the vacuum exhaust pump 20.
Keep at ^-2 Pa pressure. After the chlorine trifluoride (ClF ₃ ) gas is introduced, ultraviolet rays are radiated onto the wafer 17 through a quartz window 22 from an ultraviolet ray source 21 installed outside the etching chamber 8.

In the present invention, a low pressure mercury lamp is used as the ultraviolet light source 21. In the ultraviolet spectrum of the low-pressure mercury lamp, the irradiance at a wavelength of 253.7 nm is particularly large. When the chlorine trifluoride (ClF ₃ ) gas introduced is irradiated with ultraviolet rays, it absorbs the ultraviolet rays and is electronically excited or vibrationally excited, and finally photodecomposed and ionized.

When chlorine trifluoride (ClF ₃ ) is ionized, two kinds of anions, chlorine ion (Cl ⁻ ) and fluorine ion (F ⁻ ) are generated. Bromine ions (Br ⁺ ) are introduced into the etching chamber 8 from the ionization chamber 7, and chlorine trifluoride (ClF ₃ ) is introduced into the etching chamber 8 while the trench hole is being formed in the wafer 17.
When ultraviolet rays are irradiated from 1, the chlorine ions (Cl ⁻ ) and the fluorine ions (F ⁻ ) are generated, but these anions generated near the sidewall of the trench hole have a certain probability of positively charging the silicon single crystal lattice. Be drawn into.

The anions trapped in the silicon lattice forming the sidewalls of the trench hole form and desorb silicon tetrachloride (SiCl ₄ ) and silicon tetrafluoride (SiF ₄ ) having high vapor pressure according to the following equation. To etch the silicon grid. _{^{Si + + 4Cl - → SiCl 4}} ↑ formula ^{(1) Si + + 4F -} → SiF 4 ↑ formula (2)

[0028] As described above, when excited by ultraviolet light resulting chlorine ions (Cl ^-) and fluoride ions (F ^-) is effective to cause side etching attacks the trench side wall of the hole. However, since the movement of these anions is disordered, it is impossible to control the side etching to control the shape of the side wall of the trench.

Therefore, in the present invention, the parallel plate electrode 23 and the mesh-shaped magnet coil 16 are installed in the etching chamber 8 to control the movement of anions.

First, the parallel plate electrodes 23 are installed on both sides of the sample table 18, and a DC voltage of 6 V is applied between the electrodes to generate an electric field E parallel to the wafer 17. When the electric field E is generated, the output of the microwave oscillator 9 is stopped and the introduction of bromine ions (Br ⁺ ) from the ionization chamber 7 into the etching chamber 8 is stopped. This is to prevent the electric field E generated on the wafer 17 from disturbing the trajectory of bromine ions (Br ⁺ ). When this electric field E is generated, chlorine ions (Cl
^-) and fluorine ions (F ^-), such anions having a moving velocity v in a direction parallel with the wafer 17. The voltage application to the parallel plate electrode 23 is temporarily terminated in 1 μsec.

When the voltage application to the parallel plate electrodes 23 is completed, the output of the microwave oscillator 9 is raised again to introduce bromine ions (Br ⁺ ) into the etching chamber 8 to anisotropically etch the wafer 17. At the same time, a current of 50 mA is applied to the winding of the mesh magnet coil 16 at the same time to generate a magnetic field B on the wafer 16. The magnetic field B applies a current to the winding of the mesh magnet coil 16 so that it has a vertically downward direction. Since the magnetic field B is vertically downward, the bromine ion (Br ⁺ ) introduced from the ionization chamber 7 is only accelerated and does not interfere with the anisotropic etching of the bromine ion (Br ⁺ ).

However, since all the anions existing in the etching chamber 8 are moving at a uniform velocity with a moving velocity v parallel to the wafer 17, if a vertically downward magnetic field B is generated, Receives the Lorentz force F given by. F = ev × B (e is an elementary charge) Formula (3) The direction of the Lorentz force F is parallel to the wafer 17, but is perpendicular to the moving direction of the anions.

Therefore, the Lorentz force F becomes a centripetal force, and all anions move in a uniform circular motion. The constant-velocity circular motion of the negative ions is generated in the magnetic field B in the horizontal plane of the wafer 17.
Is used as the axis, the side etching is caused by the collision with the silicon lattice on the side wall of the trench hole during the circular movement.

When side etching occurs, the moving speed v
This step is completed in 5 μsec because the number of anions having γ is reduced. After this, returning to the beginning again, the output of the microwave oscillator 9 and the current application to the mesh-shaped magnet coil 16 are stopped, a voltage of -6 V is applied to the parallel plate electrodes 23, and the horizontal movement of all the negative ions again occurs. Have velocity-v.

A trench hole is formed in the wafer 17 by repeating this process in 1 μsec, and then repeating the output of the microwave oscillator 9 and the current application of the mesh-shaped magnet coil 16 for 5 μsec.

FIG. 2A shows a timing schedule of voltage application to the parallel plate electrodes 23, FIG. 2B shows a timing schedule of output of the microwave oscillator 9, and FIG. 2C shows a mesh magnet. 4 illustrates a terminal schedule for applying current to coil 16.

As described above, in the present invention, bromine ion (Br
^{While the} trench hole is anisotropically etched due to the straightness of ⁺ ), anions (Cl ⁻ , F ⁻ ) attack the side wall of the trench hole and side etch. Since the negative ions make a uniform circular motion in the horizontal plane, they collide perpendicularly with the sidewall of the trench hole.

As a result, it becomes possible to arbitrarily control the shape of the side wall of the trench hole. Next, the mechanism will be explained.

The anions (Cl ^-, F ^-) side etching rate with the anion (Cl ^-, F ^-) was proportional to the spatial density of the excitation efficiency of the space density of 3 chlorine trifluoride (ClF ₃₎ molecule Proportional. Since the excitation efficiency of gas molecules is proportional to the illuminance of the light source, and the illuminance of the light source is determined by the lamp voltage of the light source, the side etching rate is ultimately the parallel plate electrode 23.
If the applied voltage and the applied current to the mesh-shaped magnet coil 16 are constant, it is proportional to the lamp voltage of the ultraviolet source 21 (low-pressure mercury lamp). FIG. 3 is a plot of the relationship between the lamp voltage of the ultraviolet source 21 (low-pressure mercury lamp) and the side etching rate of the trench hole in the dry etching apparatus of the present invention. As can be seen from FIG. 3, the ramp voltage up to 350 V is a linear region where the side etching rate increases linearly. Anion lamp voltage is generated exceeds 350V (Cl ^-, F ^-)
Saturates and the side etch rate no longer shows a linear increase. Side etching rate f in a straight line area
There is a relationship of f = αV equation (4) between [Å · min ⁻¹ ] and the lamp voltage V [V], and α = 0.6Å · min ⁻¹ · V ⁻¹ .

Consider the process of forming a trench hole in a single crystal silicon substrate using the above ECR dry etching apparatus. FIG. 4 is a conceptual sectional view for deriving the shape of the sidewall of the trench hole. The shape of the side wall of the trench hole when the trench hole 3 is excavated by using the ECR dry etching apparatus of the present invention on the single crystal silicon substrate 1 coated with the photoresist 2 which is patterned so as to partially form the opening portion is shown. , Photoresist 2
Is a function F (x) of the distance x measured vertically downward from the lower part of.

If the depth of the trench hole 3 is T, then F
(X) is a function of x defined in the range of 0 ≦ x ≦ T. In the following, discussion will be carried out for the purpose of deriving F (x) as a linear expression of x. If F (x) can be derived as a linear equation of x, the shape of the side wall of the trench hole can be arbitrarily controlled and designed. 0 ≦ x ≦ T
Side etching amount F at vertical depth x within the range of
(X) is given by the following equation, where t _x is the depth x and the time required for anisotropic etching with bromine ions (Br ⁺ ).

[0042]

[Equation 1]

F is the side etching rate represented by the equation (4), and t _total is the total etching time from the start of etching to the end thereof. When the etching rate of anisotropic etching of bromine ions (Br ⁺ ) introduced from the ionization chamber 7 is β, t _total = T / β t _x = x / β Formula (6) is obtained. In FIG. 1, a voltage controller 24 capable of arbitrarily controlling the lamp voltage of the ultraviolet light source 21 as a function of time is installed so that the lamp voltage V is an exponential function of time t, particularly, the lamp voltage V decreases with time. Consider controlling as an exponential function. V (t) = V ₀ exp (−γt) (γ> 0) Formula (7)

The initial voltage V ₀ is set within the linear region of 0 ≦ V ₀ ≦ 350V. When the side etching rate f is obtained by substituting the equation (7) into the equation (4), the following function of time is obtained. f (t) = αV ₀ exp (−γt) (α = 0.6Å · min ⁻¹ · V ⁻¹ ) Formula (8) Substituting Formula (6) and Formula (8) into Formula (5), If the integration is solved, the shape F (x) of the side wall of the trench hole becomes a function of x as in the following equation. F (x) = (αV ₀ / γ) {exp [− (γ / β) x] −exp [− (γ / β) T] Formula (9) From the formula (9), the trench hole It can be seen that the side wall has an outwardly sloping and gentle shape with an exponential curvature. α = 0.6Å ・ min ^-1・
Since it is known that the etching rate of anisotropic etching by V ⁻¹ and bromine ion (Br ⁺ ) is β = 5000Å · min ⁻¹ , the initial ramp voltage V ₀ (0 ≦ V ₀ ≦ 350V) and the depth of the trench hole By selecting T and the attenuation rate γ (γ> 0), the shape of the side wall of the trench hole can be arbitrarily controlled.

As described above, according to the present invention, the shape of the side wall of the trench hole can be a curve having an outward expansive and gentle curvature of exponential function, and the curvature of the side wall shape is arbitrarily controlled as a function in the depth direction. be able to. As a result, it is possible to obtain a trench hole having a shape which cannot be obtained by the conventional method in which the corner of the opening is an obtuse angle.

It has been explained above that the shape of the side wall of the trench hole can be arbitrarily designed by the present invention. Next, a peculiar effect obtained when the present invention is applied to an actual semiconductor device manufacturing process will be described. Figure 8
(A)-(d) is sectional drawing for demonstrating the manufacturing method of the semiconductor device to which this invention is applied. In FIG. 8 (a),
A photoresist 2 is formed as an etching mask for forming a trench hole on the single crystal silicon substrate 1 by using a normal lithography technique, and is patterned. In FIG. 8B, the trench hole 3 is formed using the ECR dry etching apparatus of the present invention.
In FIG. 8C, the photoresist 2 is removed, and finally, a normal chemical vapor deposition method is used to form a buried substance 4 in the trench hole 3 as shown in FIG. The process of forming the element isolation region or the trench capacitor cell is completed.

Since the trench hole formed by using the ECR dry etching apparatus of the present invention has a side wall having an outwardly widening and gentle curvature and an obtuse angled corner portion 25,
The step coverage of the burial material to be formed later becomes good, and the reaction molecules of the burial material wrap around deep inside the trench hole 3 and grow. As a result, voids are eliminated, and defects such as cracks in the burial material are eliminated. ..

(Second Embodiment) Next, a second embodiment of the present invention will be described. In Example 1, the timing / schedule of voltage application to the parallel plate electrodes 23 is changed to the shape shown in FIG. That is, the pulse voltage of the rectangular voltage pulse is not changed in the initial stage of etching, but the pulse voltage is gradually decreased as the etching is completed (t _total = T / β).

When the pulse voltage decreases, anions (Cl
^-, F ^-) horizontally moving velocity v with the decreases, the collision efficiency into the trench side wall of the hole is reduced, as a result, side etching rate f decreases.

When the lamp voltage of the ultraviolet source 21 is changed as an exponential function of time as in the first embodiment, the sidewall of the trench hole has an exponential curvature. 5 is changed as shown in FIG. 5, the side etching rate f immediately before the end of etching is reduced. As a result, as shown in FIG. 6, the bottom portion 26 of the trench hole 3 has a round shape with a round shape. Become.

In the trench hole 3 having the round-shaped bottom portion 26 of FIG. 6, the reaction gas molecules sneak well at the bottom portion in the subsequent chemical vapor deposition process of the burying material, and the step coverage is remarkably improved. To do. Therefore, improvement in yield and reliability of semiconductor elements can be expected.

[0052]

As described above, the present invention is generated by exciting the electric field in the horizontal direction with respect to the etching wafer surface and the magnetic field in the vertical direction, and irradiating the chlorine trifluoride gas introduced into the etching chamber with ultraviolet rays. By promoting side etching with the generated anions and changing the ultraviolet intensity with time, it has the effect of making it possible to make the shape of the side wall of the etched trench hole a curve with an outward expansive and gentle exponential curvature. ..

Therefore, it is possible to obtain a trench hole having a shape which cannot be obtained by the conventional method in which the corner of the opening is an obtuse angle. There is also an effect that the curvature of the side wall shape can be arbitrarily controlled as a function in the depth direction.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

2A, 2B, and 2C are diagrams showing timing schedules used in the first embodiment of the present invention.

FIG. 3 is a plot diagram showing a relationship between an ultraviolet source, a lamp voltage, and a side etching rate.

FIG. 4 is a cross-sectional view showing a sidewall shape of a trench hole.

FIG. 5 is a diagram showing a timing schedule used in Example 2 of the present invention.

FIG. 6 is a cross-sectional view showing a sidewall shape of a trench hole obtained in Example 2 of the present invention.

7A, 7B, 7C, and 7D are cross-sectional views showing a conventional method for manufacturing a semiconductor device.

8 (a), (b), (c), and (d) are cross-sectional views showing a method for manufacturing a semiconductor device using the present invention.

[Explanation of symbols]

 1 Single Crystal Silicon Substrate 2 Photoresist 3 Trench Hole 4 Buried Material 5 Sharp Corner 6 Void 7 Ionization Chamber 8 Etching Chamber 9 Microwave Oscillator 10 Microwave Waveguide 11 Hydrogen Bromide Cylinder 12 Mass Flow Controller 13 Vacuum Exhaust Pump 14 Magnet Coil 15 Ion extraction electrode 16 Mesh magnet coil 17 Wafer 18 Sample stage 19 Chlorine fluoride cylinder 20 Vacuum exhaust pump 21 Ultraviolet source 22 Quartz window 23 Parallel plate electrode 24 Voltage controller 25 Obtuse angled corner 26 Round bottom

Claims (3)

[Claims] 1. A dry etching method in which a microwave and a magnetic field are mutually interfered to cause an electron cyclotron resonance phenomenon to turn a gas into plasma and a wafer surface is etched, and an electric field is excited in a horizontal direction with respect to the wafer surface. With
A dry etching method characterized by exciting a magnetic field in a vertical direction and irradiating a wafer surface with ultraviolet rays to perform etching. 2. A parallel plate electrode, a magnet coil,
It is a dry etching device that has an ultraviolet ray source, causes microwaves and magnetic fields to interfere with each other, causes an electron cyclotron resonance phenomenon, and turns gas into plasma, and etches the wafer surface.The parallel plate electrodes are installed in the etching chamber. The magnet coils are placed on both sides of the wafer, and the electric field is excited in the horizontal direction with respect to the wafer surface.The magnet coils are placed above and below the wafer installed in the etching chamber, and the magnetic field introduced into the etching chamber is applied to the wafer. The etching apparatus is characterized in that it is excited in a direction perpendicular to the surface, and the ultraviolet ray source irradiates the wafer surface in the etching chamber with ultraviolet rays. 3. The etching apparatus according to claim 2, wherein the power source voltage of the ultraviolet source, the applied voltage of the parallel plate electrodes, and the applied current of the magnet coil are controlled as a function of time. Etching equipment.