JP3082331B2 - Semiconductor manufacturing apparatus and semiconductor device manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION This invention relates to a semiconductor manufacturing equipment Hoyo
More specifically, the present invention relates to a dry etching apparatus for performing etching using plasma in a semiconductor manufacturing process or a plasma CVD apparatus for forming a film using plasma in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art FIG. 9 is a schematic diagram showing a conventional dry etching apparatus described in, for example, Japanese Patent Application Laid-Open No. 61-75527. In the figure, 1 is a plasma generation chamber for generating plasma, 5 (5A to 5C) are ion extraction electrode plates for extracting ions from plasma in the plasma generation chamber 1 to form a shower ion beam, and 6 is a shower ion beam Chamber for irradiating the surface of the sample (wafer substrate) 8 with
Reference numeral 7 denotes a sample table on which a sample (wafer substrate) 8 is placed, 11 denotes a gas inlet, 12 denotes an exhaust system for evacuating the sample chamber 6, 13 denotes a microwave introduction window provided in the plasma generation chamber 1, and 14 denotes It is a rectangular waveguide for introducing microwaves and connected to a microwave source (not shown). Reference numeral 15 denotes a magnetic coil provided on the outer periphery of the plasma generation chamber 1 for generating a magnetic field required to cause electron cyclotron resonance.

Next, the operation of the above dry etching apparatus will be described. First, after evacuating the plasma generation chamber 1 and the sample chamber 6, a Freon-based or chlorine-based reactive gas is introduced from the gas inlet 11, the pressure is set to a predetermined value, and microwaves are introduced into the microwave introduction window 13. Introduce more. When the frequency of the microwave is 2.45 GHz, a magnetic field of 875 gauss necessary for causing electron cyclotron resonance in the plasma generation chamber 1 is generated by the magnetic coil 15 to generate plasma in the plasma generation chamber 1. The generated plasma controls the reactive species by the ion extraction electrode plate 5, and is then transported as a shower-like ion beam to the sample chamber 6, where the sample (wafer substrate) 8 is etched.

[0004]

The conventional dry etching apparatus is configured as described above, and some of the plasma generated in the plasma generation chamber 1 is diffused to the side wall surface of the plasma generation chamber 1. Disappears. Therefore, the plasma density in the peripheral portion is lower than that in the central portion of the plasma generation chamber 1. Further, the energy distribution of the microwave injected into the plasma reaction chamber 1 is also small in the vicinity of the microwave introduction window, that is, in the center of the plasma reaction chamber because the microwave introduction window 13 is smaller than the inner diameter of the plasma generation chamber 1. It becomes a factor which becomes strong and the plasma density distribution becomes non-uniform. That is, the plasma density in the radial direction of the plasma generation chamber 1 has a non-uniform distribution that is high at the center and low at the periphery.
The non-uniformity of the plasma density in the inner diameter direction of the plasma generation chamber 1 is reflected in the density distribution of the reactive species transported onto the surface of the sample 8, and thus causes a problem that the etching rate in the surface of the sample 8 becomes non-uniform. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a semiconductor manufacturing apparatus and a semiconductor which generate plasma with a uniform distribution density and perform etching or film formation with good uniformity. An object of the present invention is to provide a method for manufacturing a device .

[0006]

A semiconductor device according to the present invention has a cylindrical plasma reaction chamber for generating plasma,
A vacuum chamber having a sample stage on which a sample is placed, gas introducing means for introducing a gas such as reactivity, and exhaust means for evacuating the chamber, magnetic field generating means for generating a magnetic field in the plasma reaction chamber, and the plasma A waveguide disposed along the circumferential direction of the plasma reaction chamber so as to surround the reaction chamber; and an opening provided on a wall surface of the waveguide on the plasma reaction chamber side so as to surround the plasma reaction chamber. And an annular portion that is provided around the entire plasma reaction chamber facing the opening of the waveguide and that introduces microwaves output from the opening of the waveguide from the entire periphery of the plasma reaction chamber . And a microwave introduction window.
Further, an ion extraction electrode may be provided between the plasma reaction chamber and the sample stage in the vacuum champer.
Further, the microwave introduced into the waveguide may be a microwave generated by a plurality of microwave generators. Further, a means for adjusting the coupling between the microwave introduced from the waveguide and the plasma generated in the plasma reaction chamber may be provided. Also, the semiconductor according to the present invention
The method of manufacturing the device is based on a sample stage provided in a vacuum chamber.
The wafer is placed on the vacuum chamber and the cylinder is set in the vacuum chamber.
The introduction of reactive and other gases into the plasma reactor
In addition, an annular mask provided around the entire plasma reaction chamber
Microwave into the plasma reaction chamber from the microwave introduction window
To generate plasma, and the plasma
Etching of the placed wafer or production of CVD film
It is what makes.

[0007]

According to the semiconductor manufacturing apparatus of the present invention, a microphone is provided.
Waves are introduced along the circumferential direction of the plasma reaction chamber.
While propagating in the waveguide, the plasma reaction gradually proceeds through the opening.
Plasma from the microwave introduction window provided on the peripheral wall of the reaction room
Order is introduced into the reaction chamber, or the periphery of the plasma reaction chamber
Thus, the microwave is supplied substantially uniformly , and plasma having a substantially uniform density distribution can be formed in the plasma reaction chamber. Further, since microwaves can be introduced from a plurality of microwave generators into the annular waveguide, plasma having a more uniform density distribution can be formed. Further, by providing the microwave matching means, the coupling between the microwave and the plasma can be adjusted in detail.

[0008]

[Embodiment 1] Hereinafter, a semiconductor manufacturing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view of a dry etching apparatus to which the present embodiment is applied, and FIG. 2 is a schematic external view of the dry etching apparatus of FIG. In the figure,
101 is a plasma reaction chamber, 102 is an exhaust port for evacuating the inside of the vacuum chamber 105, 104 is a sample (wafer substrate) mounted on a sample table 103, 106 is a coil for generating a magnetic field, and 107 is a gas inlet. 110 is a vacuum chamber 105 perpendicular to the surface of the sample 104
Is an annular microwave introduction window provided on the side wall surface of the device, and is vacuum-sealed with the vacuum chamber 105 by an O-ring (not shown) or the like. The material is a microwave transmitting material such as quartz or alumina, and the size is substantially the same as that of the vacuum chamber 105. 108 is the annular microwave introduction window 110
An annular waveguide attached to the outer periphery of the vacuum chamber 105 so as to surround the plasma reaction chamber side of the waveguide.
The wall has an opening to surround the plasma reaction chamber.
Is provided. This waveguide 108 is an E-plane 111 of the illustrated waveguide (a plane parallel to an electric field in the waveguide is called an E-plane).
The part and micro vacuum chamber 105 walls constitutes the introduction window 110, transmits the microwaves of TE ₁₀ mode. Ten
9 is a microwave generator connected to the annular waveguide 108.

In the dry etching apparatus configured as described above, the inside of the vacuum chamber 105 is evacuated to a predetermined vacuum pressure through an exhaust port 102 by a vacuum exhaust device (not shown), and then a gas inlet port is provided. An etching gas is introduced from 107. Then, the microwave generator 109
When operated, the microwave propagates through the annular waveguide 108 and passes through the microwave introduction window 110 to the plasma reaction chamber 101.
To discharge the etching gas. At this time, if the intensity of the magnetic field generated by the coil 106 is set to 875 gauss in the vacuum chamber 105, plasma by electron cyclotron resonance can be formed in the plasma reaction chamber 101. The microwave propagating in the waveguide 108 is gradually coupled to the microwave introduction window 110 while propagating in the waveguide 108 in an annular shape.
Inject microwave energy into 01. The coupling state between the microwave and the plasma can be adjusted by changing the design of the thickness T of the microwave introduction window 110 in the vertical direction.

[0010] The plasma density distribution in the plasma reaction chamber 101 is generally determined by the difference between the plasma generated by the discharge and the plasma that disappears on the wall of the vacuum chamber 105. The distribution of the plasma density generated by the present embodiment is strong at the wall of the vacuum chamber 105 and weak at the center because the microwave is injected from the peripheral portion of the plasma reaction chamber 101 toward the central portion. On the other hand, the amount of extinguished plasma depends on the vacuum chamber as described in the description of the conventional example.
More on 105 walls. As a result, in the plasma reaction chamber 101 according to the present embodiment, the region where a large amount of plasma is generated overlaps with the annihilation region, and the region is balanced by the cancellation, so that the plasma density distribution is flattened. The above-described balance can be achieved by controlling the microwave power, and plasma having a uniform and uniform density distribution in the plasma reaction chamber 101 can be formed.

As a specific example, a vacuum chamber having an inner diameter of 300 mm,
Microwave with etching gas pressure 0.5mTorr , frequency 2.45GHz and magnetic flux density 875 in plasma reaction chamber
Under Gaussian conditions, the plasma density distribution in the radial direction of the plasma reaction chamber was measured by probe measurement. As a result, plasma with good uniformity was formed by adjusting the microwave power. And with this uniform plasma,
An etching process with good uniformity can be performed on the surface of the wafer substrate 104 as a sample.

Embodiment 2 FIG. In the above embodiment, the microwave is introduced into the waveguide from one place. However, if the microwave is introduced from two places as shown in FIG. 3, a plasma having a more uniform density can be formed. That is, in the case of one microwave power supply, under the condition that the discharge gas pressure is relatively high, the coupling between the microwave propagating in the annular waveguide and the plasma becomes strong. For this reason, the coupling on the side near the microwave introduction port becomes strong, and the microwave cannot be propagated uniformly over the entire circumference, so that it is difficult to form a uniform plasma.
However, as shown in FIG. 3, a first microwave generator 125 and a second microwave generator 126 are connected to the first waveguide 121 and the second waveguide 122, respectively. When power is supplied, the coupling between microwave and plasma is averaged,
A uniform plasma can be formed. In this case, part of the E-plane constituting the second waveguide 122 is part of the first waveguide 121.
A part of the E-plane constituting the first waveguide 121 is used as a termination plate of the second waveguide 122.

Embodiment 3 FIG. Further, in the above embodiment, the microwave introduction direction is set to the tangential direction of the wall of the vacuum chamber 105, but may be set to the direction shown in FIG. In this case, since the linear waveguide 132 may be attached by cutting out an arbitrary position of the annular waveguide 131 which has been formed by machining in advance, the configuration and the manufacture of the device are simplified. 133 is a microwave end plate, which smoothly guides the microwave to an annular waveguide.
Inclined for propagation into 131.

Embodiment 4 FIG. Further, in the above-described embodiment, the coupling between the microwave and the plasma is adjusted by changing the design of the thickness T of the microwave introducing window. However, the coupling may be performed with the post 142 as shown in FIG. In this case, the annular waveguide 1
41 H plane 143 (the plane perpendicular to the electric field in the waveguide is called the H plane)
Are provided with a plurality of posts 142, and microwave matching is adjusted according to the degree of insertion of the posts 142. That is, the microwave impedance is adjusted according to the degree of insertion of the post 142.

Embodiment 5 FIG. In addition to the fourth embodiment, as a means for adjusting the coupling between the microwave and the plasma, a metal matching plate 151 may be mounted so as to surround the E surface 111 of the annular waveguide 108 as shown in FIG. In this case, by adjusting the gap S in the range of S <T, matching of the microwave to the plasma is performed. Also, as described in the second embodiment, when the discharge gas pressure is relatively high, the coupling between the microwave and the plasma is strong, and there is a problem that the microwave is easily absorbed near the microwave introduction port. If S is narrowed near the microwave inlet to weaken the coupling with the plasma and gradually expands along the transmission direction, microwaves are gradually fed and uniform discharge becomes possible.

Embodiment 6 FIG. In the above embodiment, the microwave introduction window is configured to be a part of the E-plane of the waveguide. However, as shown in FIG. You may be comprised so that it may become.

Embodiment 7 FIG. As shown in FIG. 1, the semiconductor manufacturing apparatus according to the above embodiment has a plasma reaction chamber 101 and a sample chamber integrally formed, but as shown in FIG. To the ion extraction electrode 200 (20
0A, 200B, 200C), ions may be extracted from the plasma generated in the plasma reaction chamber 101 and irradiated as a shower-like ion beam onto the sample 104 in the sample chamber 201. For example, of the three electrode plates of the ion extraction electrode 200, the uppermost electrode plate 200A is the plasma reaction chamber 10A.
The same potential as 1 is applied so that a positive potential of 0 to 2 kV with respect to the ground potential is applied. The lowermost electrode plate 200C is at the ground potential and the same potential as the sample chamber 201. Intermediate electrode plate 200
B improves the parallelism of the shower-like ion beam by applying a negative potential of 0 to -300 V with respect to the ground potential,
Electrons are prevented from entering from the sample chamber side. Here, the ions are the uppermost electrode plate 200A and the lowermost electrode plate 200C.
With the voltage of 0 to 2 kV applied during the above, the sample is extracted from the plasma reaction chamber 101 and accelerated, and is turned into a shower-like ion beam and irradiated onto the sample 104.

In the above embodiment, the microwave is introduced into the plasma reaction chamber 101 from the entire periphery of the vacuum chamber 105. However, the present invention is not limited to this. Thereby, the same effect as in the above embodiment can be obtained. Furthermore, although the dry etching apparatus has been described in the above embodiment, the same effect can be obtained by applying the present invention to a plasma CVD apparatus. For example, when silane-based SiH ₄ is introduced as a CVD gas, the gas is decomposed by electric discharge and a silicon deposition film can be formed on a sample (wafer substrate).

[0019]

As described above, according to the first and second aspects of the present invention, a cylindrical plasma reaction chamber for generating plasma, a sample stage on which a sample is mounted, and a gas introduction for introducing a gas such as a reactive gas. Means, and a vacuum chamber having an exhaust means for evacuating the chamber, a magnetic field generating means for generating a magnetic field in the plasma reaction chamber, and arranged along a circumferential direction of the plasma reaction chamber so as to surround the plasma reaction chamber. And an opening provided on the wall of the waveguide on the side of the plasma reaction chamber so as to surround the plasma reaction chamber, and an opening of the plasma reaction chamber facing the opening of the waveguide. provided the entire circumference, it is provided with the annular microwave introduction window for introducing microwaves outputted from the opening of the waveguide from the entire periphery of the plasma reaction chamber, microwave, flop While propagating in the waveguide arranged along the circumferential direction of the zuma reaction chamber, it is gradually introduced into the plasma reaction chamber from the microwave introduction window provided on the peripheral wall of the plasma reaction chamber through the opening, Microwaves are supplied substantially uniformly from the periphery of the plasma reaction chamber, so that substantially uniform plasma can be formed in the plasma reaction chamber, and dry etching or film formation with good uniformity can be performed. In addition, since microwaves are introduced through the waveguide, for example, TE of low order mode
Microwaves of 10 modes can be propagated, microwaves can be stably transmitted to the waveguide even when discharge conditions in the plasma reaction chamber change, and a stable microwave electric field can be formed in the plasma reaction chamber. According to the third aspect of the present invention, since microwaves are supplied from a plurality of locations, plasma having a uniform density distribution can be formed in the entire plasma reaction chamber. Further, according to the fourth aspect of the present invention, by providing a means for adjusting the coupling between the microwave and the plasma, the matching of the microwave can be performed in detail, and the microwave can be efficiently introduced into the plasma reaction chamber. According to the invention of claim 5, the vacuum chamber is provided.
Place the wafer on the sample stage provided in the
Reacts with the cylindrical plasma reaction chamber installed in the chamber
Gas, etc., and the entire plasma reaction chamber
The plastic from the annular of the microwave introducing window provided around
Plasma is generated by introducing microwaves into the Zuma reaction chamber.
And etch the wafer placed above with this plasma.
Plasma reaction
The plasma is formed almost uniformly from around the chamber
Drying with good uniformity
Etching or film formation becomes possible.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a semiconductor manufacturing apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic perspective view showing a semiconductor manufacturing apparatus according to one embodiment of the present invention.

FIG. 3 is a plan sectional view showing a microwave waveguide portion of a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 4 is a plan sectional view showing a microwave waveguide portion of a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 5 is a side sectional view showing a microwave waveguide portion of a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 6 is a side sectional view showing a microwave waveguide portion of a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 7 is a side sectional view showing a microwave waveguide portion of a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 8 is a side sectional view showing a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 9 is a side sectional view showing a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

 101 Plasma reaction chamber 102 Exhaust port 103 Sample table 104 Sample 105 Vacuum chamber 106 Coil 107 Gas inlet 108 Waveguide 109 Microwave generator 110 Microwave introduction window 111 E-plane of waveguide 121,122 Waveguide 123,124 Termination plate 125,126 Microwave generator 131 Annular waveguide 132 Linear waveguide 133 Termination plate 141 Waveguide 142 Post 143 H-plane of waveguide 151 Matching plate 161 H-plane of waveguide 162 Waveguide 200 Ion extraction electrode 201 Sample Room

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akihiro Washitani 4-1-1, Mizuhara, Itami-shi Mitsubishi Electric Corporation, Kita Itami Works (56) References JP-A-1-187824 (JP, A) JP-A-3 −22413 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/3065 H01L 21/205

Claims (5)

(57) [Claims] A vacuum chamber having a cylindrical plasma reaction chamber for generating plasma, a sample stage on which a sample is mounted, gas introduction means for introducing a gas such as reactivity, and exhaust means for evacuating the chamber; Magnetic field generating means for generating a magnetic field in the plasma reaction chamber, a waveguide disposed along the circumferential direction of the plasma reaction chamber to surround the plasma reaction chamber, and to surround the plasma reaction chamber,
An opening provided on the wall surface of the waveguide on the side of the plasma reaction chamber; and an opening provided on the entire periphery of the plasma reaction chamber facing the opening of the waveguide, and an output from the opening of the waveguide. And an annular microwave introduction window for introducing microwaves to be introduced from all around the plasma reaction chamber. 2. The semiconductor manufacturing apparatus according to claim 1, wherein an ion extraction electrode is provided between the plasma reaction chamber and the sample stage in the vacuum champer. 3. The semiconductor manufacturing apparatus according to claim 1, wherein the microwave introduced into the waveguide is a microwave generated by a plurality of microwave generators. 4. The semiconductor manufacturing apparatus according to claim 1, further comprising means for adjusting the coupling between the microwave introduced from the waveguide and the plasma generated in the plasma reaction chamber. 5. A wafer stage provided in a vacuum chamber.
Place the eha, the cylindrical shape provided in the vacuum chamber
While introducing gases such as reactivity into the plasma reaction chamber,
An annular microphone provided around the entire plasma reaction chamber
Microwave into the plasma reaction chamber through the
To generate a plasma, and the plasma described above
Etching of the placed wafer or generation of CVD film
Semiconductor device manufacturing method.