JPH07153598A - Control method for magnetron reactive ion etching device - Google Patents

Abstract

PURPOSE:To minimize always the maldistribution in the density distribution of a plasma by switching a device so that the magnetic field direction appears almost uniformly to sets of electromagnetic coils around a shaft vertical to a wafer surface. CONSTITUTION:Etching gas is introduced between an anode electrode 30 and a cathode electrode 40, and pressure is reduced by a vacuum pump. An electric field E is generated toward the cathode electrode from the anode electrode 30 by RF electric power on the cathode electrode 40. A magnetic field B is generated in the vertical direction to the magnetic field E by an electric current flowing to electromagnetic coils 10, 11, 20 and 21, and plasma 70 is generated. An ion in the plasma 70 repeats collision by the electric field E, and plasma density is increased. An interval of a line of magnetic flux by the magnetic field B generated from the two sets of magnetic coils does not depend on a time change, and becomes large on the whole surface of a wafer. Since a magnetic field gradient is small, drift motion of an electron in the plasma 10 is stabilized on the whole surface of the wafer 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a magnetron reactive ion etching apparatus for improving a dry etching method in a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art A reactive sputter etching method or a reactive ion etching (RIE) method is well known as one of dry etching methods in a semiconductor device manufacturing process.

In the usual magnetron RIE apparatus shown in FIG. 1, a radio frequency (RF) power is applied to the cathode electrode 40 on which the wafer 50 is placed to generate an electric field E, and the magnetron RIE apparatus is arranged around the wafer 50. Electromagnetic coil 10,1
A plasma 7 generated in a vacuum is generated by applying a current to 1, 20 and 21 to generate a magnetic field B orthogonal to the electric field E.
0 is confined in the space near the wafer 50. Inside the plasma 70, electrons cause a drift due to an electric field E and a magnetic field B which are perpendicular to each other, that is, a cycloidal motion to increase the frequency of inelastic collisions, so that the plasma density becomes high.

The electromagnetic coils 10 and 11 are arranged so as to face each other with the wafer 50 interposed therebetween, and are usually connected in series. Further, the electromagnetic coils 20 and 21 are arranged to face each other with the wafer 50 sandwiched therebetween, and are usually connected in series.

When the direction of the magnetic field B with respect to the wafer is relatively fixed in this way, the density distribution of the plasma in the plane of the wafer is greatly deviated, so that the magnetic field B with respect to the wafer.
It is necessary to relatively rotate the directions of. Here, rotating the wafer while fixing the direction of the magnetic field B involves hardware difficulties such as rotating the RF power supply. Therefore, the coil current is usually controlled so that the wafer is fixed and the direction of the magnetic field B is rotated.

Conventionally, the current I ₁ in the electromagnetic coils 10 and 11 and the current I ₂ in the electromagnetic coils 20 and 21 are respectively I ₁ = I ₀ cos (2πft) (1) I ₂ = I ₀ sin (2πft) (2) However, it is set with a phase difference π / 2 such as I ₀ : amplitude, f: frequency, t: time.

In the conventional coil current timing chart shown in FIG. 7, both the amplitude and the cycle of the coil current are standardized as 1, and the coil current is digitally changed by dividing the cycle into 50. . FIG. 7A shows the current I ₁ in the electromagnetic coils 10 and 11, and FIG.
(B) shows the current I ₂ in the electromagnetic coils 20 and 21. The rotation speed of the magnetic field B is, for example, about 0.5 Hz.

[0008]

In the conventional rotation of the magnetic field B by the coil currents I ₁ and I ₂ , the density distribution of the plasma is greatly increased with respect to the position on the wafer due to the distribution of the magnetic flux lines by the magnetic field B. Is changing.

The phases of the coil currents I ₁ and I ₂ are 2πft = nπ / 2 (3) However, when n is an integer, it is applied to either one of the set of electromagnetic coils 10 and 11 or the set of electromagnetic coils 20 and 21. An electric current flows.
On the other hand, when the phases of the coil currents I ₁ and I ₂ are (n-1) π / 2 <2πft <nπ / 2 (4), both of the electromagnetic coils 10 and 11 and the electromagnetic coils 20 and 21 are combined. An electric current flows. Therefore, the distribution of magnetic flux lines due to the magnetic field B changes with time with respect to the position on the wafer.

FIG. 8 shows the distribution of magnetic flux lines in the magnetron RIE device shown in FIG. As shown in FIG. 8A, when the phase is 2πft = 0, the gap between the magnetic flux lines 80 is large over the entire surface of the wafer 50, that is, the magnetic field gradient is small. Therefore, the drift motion of electrons in the plasma 70 is stabilized over the entire surface of the wafer 50, and uneven distribution in the plasma density distribution is minimized.

On the other hand, as shown in FIG. 8B, the phase 2πf
When t = π / 4, the distance between the magnetic flux lines 81 decreases toward the center of the wafer 50, that is, the magnetic field gradient is large. Therefore, the drift motion of electrons in the plasma 70 becomes more active in the central portion of the wafer 50 than in the peripheral portion, and the uneven distribution in the plasma density distribution is maximized.

The magnetic field gradient is a spatial gradient of magnetic field strength, and its unit is Gauss / cm.

The uneven distribution in the density distribution of this plasma is
A non-uniform distribution of the plasma current flowing from the plasma to the wafer occurs in the plane of the wafer to be etched. Therefore, for example, in the case of gate etching, a large potential difference is generated between the semiconductor substrate, the gate insulating film, and the gate electrode which are stacked to form the wafer, so that there is a problem that the gate insulating film having a relatively thin layer is destroyed. is there. Such a phenomenon generally called charge-up damage may occur in the etching process of other metals and insulating films, which is fatal to semiconductor devices.

Therefore, the present invention solves the above problems and controls the current flowing through the electromagnetic coil so as to constantly suppress the uneven distribution of plasma density in the plane of the wafer. It aims at providing the control method of.

[0015]

In order to solve the above-mentioned object, the present invention comprises a plurality of sets of electromagnetic coils which are arranged to face each other with a wafer interposed therebetween and which generate a magnetic field in the opposite directions. In a method of controlling a magnetron reactive ion etching apparatus that performs etching of a wafer surface while changing the direction of a magnetic field provided by a set of electromagnetic coils, energization for forming a magnetic field is always performed in only one set of electromagnetic coils. The energization is switched so that a combination of selection of each set of electromagnetic coils and selection of the energization direction appears substantially evenly.

The switching of the energization may be performed by rotating the direction of the magnetic field generated by the energization.

The rotation direction may be constant.

Further, the rotation direction may be periodically switched.

[0019]

According to the present invention, the direction of the magnetic field appears almost uniformly with respect to the set of electromagnetic coils around the axis perpendicular to the plane of the wafer. Here, since no current flows simultaneously to two or more sets of electromagnetic coils, the magnetic field gradient, that is, the gradient of the magnetic field strength, remains small over the entire surface of the wafer, and is almost stable irrespective of time change. Therefore, in the plasma generated above the wafer, the electron drift motion is stabilized on the entire surface of the wafer, and uneven distribution in the plasma density distribution is always minimized.

Therefore, the distribution of the plasma current flowing from the plasma to the wafer to be etched is always almost uniform in the plane of the wafer.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and operation of an embodiment according to the present invention will be described below with reference to FIGS. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

FIG. 1 shows the configuration of an embodiment of a magnetron reactive ion etching (RIE) apparatus. 1 (a) is a top view and FIG. 1 (b) is shown in FIG.
It is sectional drawing which follows the BB line of (a).

A wafer 50 constituting a semiconductor device is placed on the cathode electrode 40, and the anode electrode 3 is spaced apart from the cathode electrode 40.
It is shielded from above by 0. The cathode electrode 40 is formed in a flat plate shape, and is connected to a grounded radio frequency (RF) power supply 60. On the other hand, the anode electrode 30 is formed in a hollow box shape having an opening on one surface and is grounded.

Outside the anode electrode 30, four electromagnetic coils 10, 11, 20 and 21 are spaced from each other. The electromagnetic coils 10 and 11 are arranged to face each other with the wafer 50 interposed therebetween. In addition, the electromagnetic coil 20
21 and 21 are also arranged to face each other with the wafer 50 interposed therebetween. Although the electromagnetic coils 10 and 11 are normally connected in series, they may be connected in parallel to a power source (not shown) in order to eliminate the delay when connected in series. Also,
Separate power supplies may be used to flow currents in the same phase. The same applies to the electromagnetic coils 20 and 21.

Between the anode electrode 30 and the cathode electrode 40, an etching gas, for example, a gas such as Cl ₂ is introduced from a gas introduction hole (not shown), and a vacuum pump generates a substantially reduced pressure state. Cathode electrode 4
The electric field E is generated in the direction from the anode electrode 30 to the cathode electrode 40 by the RF power applied to 0.
Further, the magnetic field B is generated in the direction perpendicular to the electric field E by the current flowing through the electromagnetic coils 10, 11, 20 and 21.

Therefore, first, the plasma 70 is generated. The ions in the plasma 70 collide with the cathode electrode 40 or the wafer 50 thereon by the electric field E, and secondary electrons are emitted. The emitted secondary electrons cause a cycloid motion due to an electric field E and a magnetic field B which are perpendicular to each other and collide with etching gas molecules, so that ions are newly generated. Then, similarly to the above, the ions further collide with the cathode electrode 40 or the wafer 50 thereon by the electric field E, and secondary electrons are emitted again. This repeatedly occurs and the plasma density increases. By increasing the plasma density in this way, the plasma 7
A large number of reactive ions are supplied to the wafer 50 from 0,
Si or a compound thereof, or various metals are etched at high speed.

FIG. 2 shows an example of a timing chart of the coil current in the above embodiment. 2A shows the current I ₁ in the electromagnetic coils 10 and 11, and FIG.
(B) shows the current I ₂ in the electromagnetic coils 20 and 21. Also, these coil currents are rectangular waves, and are standardized with both the amplitude and the period being 1.

Current I ₁ in the electromagnetic coils 10 and 11
And the current I ₂ in the electromagnetic coils 20 and 21 are I ₁ = I ₀ {nT ≦ t <(n + 1/4) T} (11) 0 {(n + 1/4) with respect to the rotation period T of the magnetic field B, respectively. ) T ≦ t <(n + 1/2) T, (n + 3/4) T ≦ t <(n + 1) T} T} -I 0 {(n + 1/2) T ≦ t <(n + 3/4) T}, I ₂ = I ₀ {(n + 1/4) T ≦ t <(n + 1/2) T} (12) 0 {nT ≦ t <(n + 1/4) T, (n + 1/2) T ≦ t <(n + 3/4) ) T} -I ₀ {(n + 3/4) T ≦ t <(n + 1) T} where I ₀ : amplitude, t: time, n: integer.

Due to such changes with time of the coil currents I ₁ and I ₂ , the direction of the magnetic field B rotates about an axis perpendicular to the plane of the wafer 50. The magnetic field rotation speed is, for example, about 0.5 Hz.

Next, the operation of the above embodiment will be described.

According to the coil currents I ₁ and I ₂ , first,
At the first time T / 4 obtained by dividing the rotation period T of the magnetic field B by the total number of electromagnetic coils of 4, a current I ₀ flows through the first set of electromagnetic coils 10 and 11, and the second set of electromagnetic coils 20 and Two
No current flows through 1. At the next T / 4, the current I ₀ flows through the second set of electromagnetic coils 20 and 21, and the current does not flow through the first set of electromagnetic coils 10 and 11. At the next T / 4, the current −I _{0 in the} opposite direction to the current flows in the first set of electromagnetic coils 10 and 11, and the current does not flow in the second set of electromagnetic coils 20 and 21. In the next T / 4, the second set of electromagnetic coils 2
A current −I ₀ flows through 0 and 21, and the first set of electromagnetic coils 1
No current flows through 0 and 11.

Two such sets of electromagnetic coils 10 and 11
The distance between the magnetic flux lines 80 due to the magnetic field B generated from the electromagnetic coils 20 and 21 is large over the entire surface of the wafer 50 without depending on the time change, that is, the magnetic field gradient is small.
Therefore, the drift motion of electrons in the plasma 70 is stabilized on the entire surface of the wafer 50, and uneven distribution in the plasma density distribution is always minimized.

The magnetic field gradient is a gradient of spatial magnetic field strength, and its unit is Gauss / cm.

Therefore, the distribution of the plasma current flowing from the plasma 70 to the wafer 50 to be etched is substantially uniform in the plane of the wafer. Therefore, in gate etching or the like for semiconductor devices on the wafer 50,
The occurrence of charge-up damage is reduced.

FIG. 3 shows the coil current overlap phenomenon in the above embodiment. The current flowing through the magnetic field generating electromagnetic coil may be distorted in its waveform due to the influence of the current control system. Therefore, the current waveforms of the electromagnetic coils arranged adjacent to each other temporally overlap.
For example, the current waveforms in the electromagnetic coils 10 and 11 are distorted as illustrated by the solid line 12, and the overlap region 100 is generated with respect to the current waveforms in the electromagnetic coils 20 and 21 illustrated by the dotted line 22. At this time, currents simultaneously flow through the two sets of electromagnetic coils, and the magnetic field gradient in the plane of the wafer 50 becomes large.

However, if such an overlap time is extremely short, that is, if the pulse excitation time is 10
Within about%, the amount of electric charge that charges up the semiconductor device on the wafer 50 is extremely small. Therefore, the occurrence of charge-up damage is suppressed.

Next, the actual measurement result of the charge-up evaluation in the above-mentioned embodiment will be described.

The charge-up evaluation method is MN
The shift amount ΔV _FB of the flat band voltage V _{FB in} the OS (Metal-Nitride-Oxide-Semiconductor) diode was measured. The MNOS diode is formed by sequentially stacking a gate insulating film made of a SiO ₂ layer and a Si ₃ N ₄ layer and a gate electrode made of poly-Si on a p-type semiconductor substrate made of Si. It is possible to detect the electric charge charged by the charge-up by converting it to the shift amount ΔV _FB of the flat band voltage V _FB .

When the gate applied voltage V _A is applied to the MNOS diode, charges are injected into the gate insulating film in accordance with the potential and the polarity relative to the semiconductor substrate, which shifts the flat band voltage V _{FB of the} MNOS diode. To do. First, using this phenomenon, M
The gate applied voltage V _A of the NOS diode is varied, and the shift amount ΔV _FB of the flat band voltage V _{FB with} respect to each value of the gate applied voltage V _A is detected, and V _A −ΔV
I investigated the _FB relationship.

Next, by the usual CV measurement, MNOS
The initial flat band voltage V _FB1 in the diode was calculated.

Next, on the cathode electrode 40 of the magnetron RIE apparatus shown in FIG.
The S diode was mounted. Subsequently, the coil current was controlled by the method of the present invention and the conventional method, and a normal etching process was performed. The etching conditions are shown below.

RF output: 125 W Pressure: 100 mTorr Etching gas flow rate: HBr 60 sccm Cl ₂ 20 sccm He-O ₂ 4 sccm (volume ratio He 95%, O ₂ 5%) Magnetic field intensity: 30 Gauss Etching time: 180 sec Next, a MNOS diode is used as a magnetron. The flat band voltage V _FB2 after being taken out from the RIE device and similarly processed
Was calculated.

Next, the shift amount ΔV _FB = V _FB2 −V _FB1 of the flat band voltage V _FB is calculated, and this ΔV _{FB is applied} to the previously obtained V _A −ΔV _FB relationship of the MNOS diode. Conversely, the value of V _A was obtained.

The value of V _A thus obtained corresponds to the voltage charged up in the gate electrode of the MNOS diode during etching. Therefore, the potential and polarity of the gate electrode relative to the semiconductor substrate can be estimated.

The charge-up evaluation as described above is described in detail in the document "Dry Proces Symposium, pp.132-137, 1985" and the publication "Jikkei 2-041924".

As a result, the shift amount ΔV _FB of the flat band voltage V _FB in the MNOS diode was obtained as shown in Table 1.

[0047]

[Table 1]

Therefore, according to the control method of the magnetron reactive ion etching apparatus of the present invention, the shift amount ΔV _FB of the flat band voltage V _FB is reduced to about 1/4 of the conventional method. Therefore, along with this, the occurrence of charge-up damage is also reduced.

The present invention is not limited to the above embodiment, but various modifications can be made.

For example, in the above-mentioned embodiment, the time section in which the coil current is not modulated has the same section length. However, if the sections are not necessarily set to the same section length and are relatively close to each other, the same operation effect is obtained. Is obtained.

Further, although the coil current has a rectangular wave in the above-mentioned embodiment, the same operational effect can be obtained without necessarily setting it in a pulse shape.

FIG. 4 shows a modification of the timing chart of the coil current in the above embodiment. Note that FIG.
Indicates the current I ₁ in the electromagnetic coils 10 and 11, and FIG.
(B) shows the current I ₂ in the electromagnetic coils 20 and 21. Further, both the amplitude and the period of the coil current are standardized as 1, and the coil current digitally changes with time by dividing the magnetic field rotation period into 50.

Current I ₁ in the electromagnetic coils 10 and 11
And the current I ₂ in the electromagnetic coils 20 and 21 are respectively I ₁ = I ₀ sin (2πft) (13) {nT ≦ t <(n + 1/4) T} 0 {(n + 1/4) T ≦ t < (N + 1/2) T, (n + 3/4) T ≦ t <(n + 1) T} T} I ₀ sin (2πft−π) {(n + 3/4) T ≦ t <(n + 1) T} I ₂ = I ₀ sin (2πft−π) (14) {(n + 1/4) T ≦ t <(n + 1/2) T} 0 {nT ≦ t <(n + 1/4) T, (n + 1/2) T ≦ t <( n + 3/4) T} I ₀ sin (2πft) {(n + 3/4) T ≦ t <(n + 1) T} where f: frequency is set.

Further, although the number of sets of electromagnetic coils is two in the above embodiment, the same effect can be obtained even if the number is larger.

FIG. 5 shows a modification of the arrangement of the electromagnetic coils in the above embodiment. Eight electromagnetic coils 110, 111, 1 are provided outside the anode electrode 30 that shields the wafer 50.
20, 121, 130, 131, 140, 141 are separated from each other. The electromagnetic coils 110 and 111 are
The wafers 50 are arranged so as to face each other with the wafer 50 sandwiched therebetween. Further, the electromagnetic coils 120 and 121 are arranged to face each other with the wafer 50 interposed therebetween. Also, the electromagnetic coil 1
30 and 131 are arranged to face each other with the wafer 50 interposed therebetween. Further, the electromagnetic coils 140 and 141
Are arranged to face each other with the wafer 50 in between.

Although the electromagnetic coils 110 and 111 are normally connected in series, they may be connected in parallel to a power source (not shown) in order to eliminate the delay when connected in series.
Also, different power supplies may be used to flow currents in the same phase. The same applies to the electromagnetic coils 120 and 121, the electromagnetic coils 130 and 131, or the electromagnetic coils 140 and 141.

FIG. 6 shows an example of a coil current timing chart in a modification of the electromagnetic coil arrangement. FIG. 6A shows a current I ₁₁ in the electromagnetic coils 110 and 111.
6B shows the current I ₁₂ in the electromagnetic coils 120 and 121, and FIG. 6C shows the electromagnetic coils 130 and 1.
31 shows the current I ₁₃ and FIG. 6 (d) shows the current I ₁₄ in the electromagnetic coils 140 and 141. The amplitude and the cycle of the coil current are both standardized as 1.

The current I ₁₁ in the electromagnetic coils 110 and 111 and the current I ₁₂ in the electromagnetic coils 120 and 121
And the current I ₁₃ in the electromagnetic coils 130 and 131,
The currents I ₁₄ in the electromagnetic coils 140 and 141 are respectively I ₁₁ = I ₀ {nT ≦ t <(n + 1/8) T} (15) 0 {(n + 1/8) T ≦ t <(n + 1/2) T , (N + 5/8) T ≦ t <(n + 1) T} −I ₀ {(n + 1/2) T ≦ t <(n + 5/8) T}, I ₁₂ = I ₀ {(n + 1/8) T ≦ t <(N + 1/4) T} (16) 0 {nT ≦ t <(n + 1/8) T, (n + 1/4) T ≦ t <(n + 5/8) T, (n + 3/4) T ≦ t <( n + 1) T} -I ₀ {(n + 5/8) T ≦ t <(n + 3/4) T} I ₁₃ = I ₀ {(n + 1/4) T ≦ t <(n + 3/8) T} (17) 0 {NT ≦ t <(n + 1/4) T, (n + 3/8) T ≦ t <(n + 3/4) T, (n + 7/8) T ≦ t <(n + 1) T} −I ₀ {(n + 3/4) ) T ≦ <(N + 7/8) T}, I 14 = I 0 {(n + 3/8) T ≦ t <(n + 1/2) T} (18) 0 {nT ≦ t <(n + 3/8) T, (n + 1 / 2) T ≦ t <(n + 7/8) T} −I ₀ {(n + 7/8) T ≦ t <(n + 1) T}.

Further, although the rotating direction of the magnetic field is constant in the above-mentioned embodiment, the same operational effect can be obtained even if the magnetic field is switched periodically.

[0060]

As described above in detail, according to the present invention, the direction of the magnetic field appears almost uniformly with respect to the set of electromagnetic coils around the axis perpendicular to the surface of the wafer. here,
Since no current flows simultaneously to two or more sets of electromagnetic coils, the magnetic field gradient, that is, the gradient of the magnetic field strength, remains small over the entire surface of the wafer, and is almost stable without depending on time change. Therefore, in the plasma generated above the wafer, the electron drift motion is stabilized on the entire surface of the wafer, and uneven distribution in the plasma density distribution is always minimized.

Therefore, the distribution of the plasma current flowing from the plasma to the wafer to be etched is always almost uniform in the plane of the wafer. Therefore, in the case of gate etching, for example, a relatively large potential difference does not occur in the semiconductor substrate, the gate insulating film, and the gate electrode which are stacked to form the wafer, and the breakdown of the gate insulating film is reduced. As described above, since the occurrence of charge-up damage during the manufacturing process of the semiconductor device is reduced, the productivity and reliability of the semiconductor device are improved.

[Brief description of drawings]

1A and 1B show a configuration of an embodiment of a magnetron RIE apparatus, FIG. 1A is a top view, and FIG. 1B is a B- of FIG.
It is sectional drawing along the B line.

2 shows an example of a coil current timing chart to which the present invention is applied in the magnetron RIE device shown in FIG. 1, in which (a) is a case of electromagnetic coils 10 and 11,
(B) is the case of the electromagnetic coils 20 and 21.

FIG. 3 is a timing chart showing an overlap phenomenon in the coil current shown in FIG.

4 shows a modification of the timing chart of the coil current to which the present invention is applied in the magnetron RIE device shown in FIG. 1, (a) shows the case of the electromagnetic coils 10 and 11, and (b) shows the electromagnetic coil 20, This is the case of 21.

5 is a schematic configuration diagram showing a modification of the arrangement of electromagnetic coils in the magnetron RIE device shown in FIG.

FIG. 6 shows an example of a coil current timing chart to which the present invention is applied in the magnetron RIE apparatus shown in FIG. 5, (a) shows the case of electromagnetic coils 110 and 111, and (b) shows electromagnetic coils 120 and 121. In the case of
(C) is the case of the electromagnetic coils 130 and 131,
(D) is the case of the electromagnetic coils 140 and 141.

FIG. 7 shows an example of a conventional timing chart of coil current in the magnetron RIE device shown in FIG.
(A) shows the case of the electromagnetic coils 10 and 11, and (b) shows the case of the electromagnetic coils 20 and 21.

8A and 8B are schematic configuration diagrams showing a distribution of magnetic flux lines in the magnetron RIE apparatus shown in FIG. 1, where FIG. 8A shows a case where the coil current phase is 0, and FIG. 8B shows a coil current phase of π /. This is the case of 4.

[Explanation of symbols]

10, 11 ... Electromagnetic coil, 12 ... Electromagnetic coil 10 and 1
1 current waveform, 20, 21 ... Electromagnetic coil, 22 ... Current waveform of electromagnetic coils 20 and 21, 30 ... Anode electrode, 4
0 ... Cathode electrode, 50 ... Wafer, 60 ... RF power supply, 7
0 ... Plasma, 80, 81 ... Magnetic flux line, 100 ... Coil current overlap region, 110, 111 ... Electromagnetic coil, 120, 121 ... Electromagnetic coil, 130, 131 ... Electromagnetic coil, 140, 141 ... Electromagnetic coil.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masashi Kondo 14-3, Niizumi, Narita, Chiba Prefecture Nogedaira Industrial Park, Applied Materials Japan Co., Ltd. (72) Inventor, Yukio Iijima 14-3, Niizumi, Narita, Chiba Prefecture Inside the Taira Industrial Park Applied Materials Japan Co., Ltd. (72) Inventor Toshiyuki Orita 1-12 Toranomon, Minato-ku, Tokyo Inside Oki Electric Industry Co., Ltd. (72) Yuro Sekiyama 1-chome Toranomon, Minato-ku, Tokyo 7-12 Oki Electric Industry Co., Ltd.

Claims (4)

[Claims] 1. A plurality of sets of electromagnetic coils arranged to face each other across a wafer and generating magnetic fields in the opposite directions,
In a method of controlling a magnetron reactive ion etching apparatus for etching the surface of a wafer while changing the direction of a magnetic field applied by a set of these electromagnetic coils, a method for forming the magnetic field only in one set of electromagnetic coils at all times. A method for controlling a magnetron reactive ion etching apparatus, wherein energization is performed and the energization is switched so that a combination of selection of each set of the electromagnetic coils and selection of an energization direction thereof appears substantially evenly. 2. The method for controlling a magnetron reactive ion etching apparatus according to claim 1, wherein the switching of the energization is performed so that a direction of a magnetic field generated by the energization is rotated. 3. The method of controlling a magnetron reactive ion etching apparatus according to claim 2, wherein the direction of rotation is constant. 4. The method of controlling a magnetron reactive ion etching apparatus according to claim 2, wherein the rotation direction is periodically switched.