JP3034692B2 - Vacuum reactor and semiconductor substrate processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention relates to a dry processing
It relates vacuum reactor and a processing method <br/> semiconductor substrate physical takes place, in particular, a vacuum reactor can be made uniform plasma density distribution generated by the device and utilizing the vacuum reactor
The present invention relates to a method for processing a semiconductor substrate .

[0002]

2. Description of the Related Art FIG.
No. is a sectional view showing a vacuum processing device used in conventional dry etching, or chemical vapor deposition as shown in such publications, in FIG, 1 is a discharge chamber over, 2 discharge Chang <br/> bar 1 A microwave waveguide that supplies microwave power to the
3 is a discharge chamber over within 1, solenoid coil to create a magnetic field for causing electron cyclotron resonance in the supplied microwave power from the microwave waveguide 2, the gas inlet into the discharge chamber 1 4, 5 Discharge chamber 1
Reaction chamber in which ions generated inside diffuse inside
Chromatography, 6 is placed in the reaction chamber over 5 generally electrically fully insulated, a sample stage in a floating potential, 7 are placed wafer on the sample stage 6. A discharge chamber -1 and the reaction chamber over 5 is maintained at a constant vacuum by the vacuum evacuation system (not shown).

Next, the operation will be described. The reaction chamber over the discharge chamber -1 by vacuum exhaust system (not shown) 5
It was maintained at a constant vacuum level, using the gas inlet 4 of the discharge chamber over 1 dry etching or chemical vapor deposition by introducing a reactive gas, as the discharge chamber-1 becomes a predetermined pressure value The amount of evacuation by a vacuum evacuation system (not shown) is adjusted. Then, when the pressure in the discharge chamber over 1 reaches a predetermined value, the microwave waveguide 2 connected to an unillustrated microwave power generating power supply and supplies a microwave power into the discharge chamber over 1. Subsequently, a magnetic field necessary to cause a microwave and electron cyclotron resonance discharge chamber over 1 by the solenoid coil 3, wherein to discharge the reaction gas the introduction, to produce electron cyclotron resonance plasma. The discharge Chang <br/> plasma generated in the bar 1, diffused along the magnetic field lines by the plasma, dry etching or chemical vapor to the sample 7 on the sample stage 6, which is installed in the reaction chamber over 5 Phase deposition or the like (hereinafter, simply referred to as dry processing) is performed.

[0004]

BRIEF Problems to be Solved by the vacuum reaction device used in conventional dry process is constructed as described above, electrons in the plasma generated in the discharge chamber over within 1 of the discharge chamber over 1 easily diffused toward the wall, because the electrons disappear in this wall, the discharge chamber -1
Electron density is reduced in the vicinity of the wall, the electron density distribution is high near the center of the discharge chamber-1 becomes the distribution as to decrease toward the wall. Therefore, the plasma, which should originally have the same concentration (density) of electrons and ions (positive ions), becomes unstable, the ions are heated, the ion temperature rises, and the direction of the ions diffused from the discharge chamber 1 is increased. And the number of ions that should enter perpendicular to the upper surface of the wafer 7 decreases, the etchability on the upper surface of the wafer 7 becomes non-uniform, and anisotropic etching cannot be performed. There was a problem.

In particular, as the diameter of the sample 7 becomes larger, the degree of non-uniformity of the electron density distribution of the plasma becomes larger, and the above-mentioned problems have become more remarkable.

[0006] The present invention has been made to solve the above problems, can prevent a decrease in electron density occurring near the inner wall of the discharge chamber over, the plasma having a uniform and uniform electron density distribution and to obtain a vacuum reactor capable of producing within the reaction chamber over.

[0007]

Means for Solving the Problems] vacuum reactor according to the invention, near the inner wall of the discharge chamber over which the electron cyclotron resonance plasma arising, discharge electrodes to generate a high-frequency discharge between the inner wall of the discharge chamber over Is provided.

Further, the vacuum reactor according to the present invention comprises:
Near the inner wall of the discharge chamber is an electron cyclotron resonance plasma arising, is provided with a heat electron supply means for supplying the thermoelectrons against the inner wall of the discharge chamber. Ma
The processing method according to claim 4 processes a semiconductor substrate.
And a method for performing the method according to any one of claims 1 to 3.
A plasma is generated in the vacuum reactor described in
It is characterized by performing dry processing on the body substrate
is there.

[0009]

[Action] In this invention, it is so arranged produces a high-frequency discharge in the vicinity of the wall of the discharge chamber over by electrons generated by the plasma by the high frequency discharge, electron density near the inner wall of the discharge chamber over is increased, the electronic reduction in electron density near the inner wall of the discharge chamber over by diffusion of electrons into the wall direction in Saikurokuton resonance plasma is suppressed, the electron density distribution in the radial direction of the electron cyclotron resonance plasma is uniform, as a result, the plasma Is kept in a stable state, and the ions can be diffused onto the wafer uniformly and at a low temperature.

[0010] In the present invention, a reduction in electron density near the wall of the discharge chamber over is to be compensated by the thermal electrons generated from the thermionic emission means, uniformly electron density distribution in the radial direction of the electron cyclotron resonance plasma Thus, the plasma can be stabilized, and the ions can be diffused uniformly and at a low temperature onto the sample.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing the structure of a vacuum reactor according to a first embodiment of the present invention.
Designate the same or corresponding parts, 8 discharge <br/> arranged so as to be parallel with the inner wall surface at a certain distance from the inner wall of the chamber-1 high frequency discharge electrode and, Reference numeral 9 denotes a high-frequency power supply connected to the high-frequency discharge electrode 8. Then, as in the conventional reactor shown the vacuum reactor in FIG. 3, the discharge chamber-1, the reaction chamber -5
The inside is evacuated by a vacuum evacuation system (not shown) and kept in a vacuum.

The operation will be described below. The basic operation is the same as the conventional reactor shown in FIG. 3, dry etching or chemical vapor deposition from the gas introducing hole 4 in the discharge <br/> chamber-1 (hereinafter, simply referred to as a dry process . the reactive gas is introduced for use in), by supplying a high frequency power from the high frequency power source 9 to the high-frequency discharge electrode 8 disposed along the inner wall surface of the discharge chamber-1, with the high-frequency discharge electrode 8 It occurs glow discharge between the discharge chamber-1, plasma is generated during this time. Then, by the generation of the plasma, electron dense plasma generated by electron cyclotron resonance by the microwave power and the magnetic field of the discharge chamber over the 1 diffuses toward the wall of the discharge chamber-1, with the wall even disappeared, the electron density in the vicinity of the wall does not decrease, the electron density distribution in the radial direction of the discharge chamber over 1 is kept uniform.

In the vacuum reactor of this embodiment,
By glow discharge between the disposed along the inner wall surface of the discharge chamber-1 was a high-frequency discharge electrode 8 and the inner wall surface of the discharge chamber-1, it is possible to increase the meantime the electron density, occurs in the conventional reactor is a reduction in electron density suppressed in the vicinity of the inner wall surface of the discharge chamber-1 which was a plasma generated from the reactive gas can be maintained in a stable state, preventing an increase in ion temperature in the plasma be able to. As a result, it is placed on the sample stage 6 as a large-diameter wafer sample into the reaction chamber over 5 improves the anisotropy of ions diffusing from the plasma in the discharge chamber-1,
In addition, the acceleration of the ions in the direction perpendicular to the upper surface of the wafer is also increased, whereby the etching properties within the wafer surface are made uniform, and the anisotropy of the etching shape can be improved. Further, the stabilization of the plasma also increases the plasma density itself, thereby improving the etching rate. Further, in the conventional reaction apparatus, in order to obtain high anisotropy, high-frequency power is applied to the sample stage 6, the sample stage 6 is maintained at a negative potential, and the diffusion of ions is accelerated to perform etching. In this reaction apparatus, highly anisotropic etching can be performed as described above without accelerating ions, and irradiation damage can be reduced.

FIG. 2 is a schematic sectional view showing the structure of a vacuum reactor according to a second embodiment of the present invention. This vacuum reactor is a high-frequency discharge electrode in the vacuum reactor of the first embodiment. instead of 8, in which is disposed at a predetermined interval between the thermionic emission filament 10 a discharge chamber-1 of the inner wall.

In the vacuum reactor of this embodiment,
Since thermal electrons are emitted toward the inner wall of the discharge chamber-1 from the filament 10, the discharge near the inner wall of the chamber over 1 high electron density, electron discharge chamber 11 in the plasma formed by electron cyclotron resonance A decrease in electron density due to diffusion to the inner wall is suppressed, the generated plasma can be kept stable, and the same effect as in the first embodiment can be obtained.

[0016] In the above-described first embodiment, a structure such that a discharge between the reaction gas introduced from the etching gas introducing hole 4 into the discharge chamber-1 and the discharge electrode 8 and the inner wall of the discharge chamber 1 and which is, from between the discharge electrode 8 and the discharge Cha <br/> Nba-1 of the inner wall may have a structure in which a rare gas (e.g., the He) is introduced, in this case, the discharge electrode 8 from the plasma by the noble gas between the inner wall of the discharge chamber-1 is produced, it is possible to deposit on the inner wall of the discharge chamber-1 is prevented from adhering, further, introducing a low molecular weight gas By doing so, the generated plasma can be further stabilized.

Further, in the second embodiment, a direct heat type thermoelectron emitting element such as a filament is provided. However, an indirectly heated thermoelectron emitting element is not limited to the filament.
In this case, the same effect as in the above embodiment can be obtained. Also, in all of the above embodiments, the etching process has been described, but when performing a reaction process such as chemical vapor deposition,
It goes without saying that a reaction with high anisotropy and excellent in reaction uniformity with respect to the upper surface of the wafer can be performed.

[0018]

As is evident from the foregoing description, according to the present invention, the discharge <br/> to be able to generate a region with a high electron density in the vicinity of the inner wall of the chamber over the electronic occurs near the inner wall of the discharge chamber over is provided with the means, is a reduction in electron density suppression in near the inner wall of the discharge chamber over, it is possible to maintain the plasma stability of the electron cyclotron resonance plasma, so that the direction of the ions diffusing from the plasma enhanced Thus, there is an effect that dry processing can be performed with high anisotropy, high uniformity, high throughput, and low damage.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration of a vacuum reactor according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a configuration of a vacuum reactor according to a second embodiment of the present invention.

FIG. 3 is a sectional side view showing a configuration of a conventional vacuum reactor.

[Explanation of symbols]

1 electron cyclotron resonance by the discharge chamber -2 microwave waveguide 3 solenoid coil 4 gas introducing hole 5 reaction chamber over 6 sample base 7 wafer 8 high-frequency discharge electrode 9 high frequency power source 10 thermionic emission filament

Claims (4)

(57) [Claims] A discharge chamber for generating electron cyclotron resonance by microwave power and a magnetic field generated by a solenoid coil in a vacuum state; and a plasma generated in the vacuum discharge chamber diffuses into the discharge chamber. In a vacuum reactor having a reaction chamber for performing a dry process on a sample disposed at a position distant from the vacuum discharge chamber, an electron generating means for increasing the electron density in this region is provided near an inner wall of the discharge chamber. A vacuum reactor characterized by being provided. 2. The vacuum reactor according to claim 1, wherein the discharge electrode is disposed in parallel with the inner wall of the discharge chamber at a predetermined interval and generates a glow discharge with the inner wall of the discharge chamber. A vacuum reactor characterized by comprising: 3. The vacuum reactor according to claim 2, wherein the thermoelectron emission means is arranged in parallel with a predetermined interval to an inner wall of the discharge chamber, and emits thermoelectrons near the inner wall of the discharge chamber. A vacuum reactor comprising: 4. A method for processing a semiconductor substrate.
And the vacuum reaction according to any one of claims 1 to 3.
Plasma is generated in the equipment and the semiconductor substrate is dried.
A method for processing a semiconductor substrate, comprising performing processing.