JPS62219927A - Dry-type thin film processing device - Google Patents

Abstract

PURPOSE:To prevent plasma generated inside a metallic container from climbing to an introduced tube path, by composing a flow path on which all of raw material gases, flowing from an outlet of a raw material gas-introduced tube path to the metallic container, container, cross a magnetic field. CONSTITUTION:A flow path 39a, which is connected to a flow path 37a and perforated inclinedly into a wall of a metallic container 39 to be opened inside the container, is formed. Since the inclination of the flow path 39a is formed so that a region A occupied by a figure of the flow path on the position of a container outer wall surface, which is projected in the direction of the magnetic field H generated by a magnetic field generation means, and a region B occupied by a projected figure of the flow path on the position of a container inner wall surface, do not overlap each other, the plasma generated inside the metallic container, which climbs in the upstream direction of the gas flow path, is needed to necessarily cross the magnetic field inside this inclined flow path. However, since the plasma can not cross the magnetic field to move, the region where the plasma can climb is limited to a left-end position in the region B and the plasma can not climb over this limit.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

This invention uses plasma to grow a semiconductor thin film or to etch a thin film on a substrate. ! A processing device comprising means for generating microwaves, means for transmitting the microwaves, a metal container coupled with the microwave transmission means, means for generating a magnetic field in the metal container, and a means for transmitting the microwaves. a raw material gas introduction pipe for introducing into the metal container a raw material gas in which one active atomic molecule or ion is formed in the metal container under the simultaneous action of waves and a magnetic field; The present invention relates to a dry single-film processing device that processes a sample surface by forming a thin film or etching it using a single active atom molecule or ion.

[Prior art and its problems 1] In the technical field to which this invention pertains, process technology using ECR plasma has recently attracted attention. What is HCR [! 1ectron Cyclotron Re5on
ance (electron cyclotron resonance), which accelerates electrons using the resonance effect of a magnetic field and microwaves, and uses the kinetic energy of the electrons to ionize gas to create plasma. Electrons excited by microwaves move circularly around magnetic lines of force, and the condition where centrifugal force and Lorentz force are balanced is called the ECR condition. When the centrifugal force is represented by srω and the Lorentz force by -qrωB, the condition for their balance is ω/B=q/fat. Here, ω is the angular velocity of the microwave, B is the magnetic flux density, and q/■ is the specific charge of the electron. The microwave frequency generally used is 2.45f; Hz, which is accepted for industrial use, and in that case 0.
．． 0875T is the resonant magnetic flux density. For example, a method shown in FIG. 5 is known as a thin film processing apparatus that applies EeR plasma. In this device, the metal container 31 and reaction tank 9 are evacuated, and the raw material gas introduction pipe 4
From N, the gas flows into the metal container 3, and the microwave is sent into the metal container 3 via the waveguide 1 and the vacuum window 2, which are its transmission means. A metal plate 7 having a large diameter hole is attached, and this metal plate and the metal container 3 form a semi-open microwave resonator. A solenoid 6 is disposed outside the resonator, and a magnetic field that satisfies the EcR condition is generated within the resonator, so that ECR plasma is generated within the resonator. This plasma is pushed out into the reaction chamber 9, and the silane gas (Sil+
) is introduced and this gas is activated by the plasma, the generated active species react with the substrate 11, which is the sample to be processed, and a thin film is formed on the surface of the substrate. This apparatus can also be used for etching a substrate by flowing an etching gas instead of the h gas from the raw material gas introduction pipe 4. Note that 5 is a cooling pipe that cools the resonator 3. Since ECR plasma has the property of moving in the direction of sparse magnetic flux density due to the effect of a diffused magnetic field, the magnetic flux density distribution inside the device is generally set up to have a profile as shown in Figure 6, so that the plasma constantly moves towards the substrate. We take care to move in the same direction. In this type of device, it is rational to have the source gas for the plasma flow in from the side opposite to the plasma outlet, but in that case, the source gas piping has conventionally been connected to the end face of the plasma chamber connected to the waveguide. It is customary to lead a stainless steel straight pipe directly from the hole provided to the end of the -H solenoid, and then to the valve, flow needle, etc. (The raw material gas piping is made of stainless steel because the inside needs to be polished. ) A direct current magnetic field still exists within this stainless steel straight pipe, and the magnetic flux density becomes sparse toward the upstream side of the gas. In this case, microwaves enter the source gas inflow path and plasma can be generated in the gas piping.Furthermore, this plasma can travel upstream of the gas, which is the opposite of the plasma in the plasma container.
The plasma penetrates deep into the gas piping. In this way, heavy metals such as chromium are liberated when the stainless steel piping comes into contact with the plasma, causing contamination of the substrate, and the temperature of the stainless steel tube, which is thin and has poor heat dissipation efficiency, increases, leading to thermochemical deterioration of the stainless steel tube. The disadvantage was that it was promoted. OBJECTS OF THE INVENTION In order to eliminate the above-mentioned conventional drawbacks, an object of the present invention is to prevent the release of heavy metals from stainless steel pipes by preventing the presence of plasma in the pipeline for introducing plasma raw material gas, and to provide a stainless steel pipe. An object of the present invention is to provide a method for introducing raw material gas to prevent thermochemical deterioration of materials due to temperature rise.

[Key points of the invention]

This invention focuses on the fact that ECR plasma cannot move with a component perpendicular to the magnetic field, and reduces all of the raw material gas flowing out from the outlet of the raw material gas introduction pipe toward the metal container. (By configuring a flow path that cannot flow into the metal container unless it crosses the magnetic field at least once, it is possible to prevent the plasma generated in the metal container from flowing into the introduction pipe. [Embodiment of the Invention] Fig. 1 shows an embodiment of a flow path formed by connecting to the outlet of the raw material gas introduction pipe based on the present invention. Raw material gas introduction pipe 33 A flow passage 37a connected to the outlet of the pipe is formed in the center of a flange 37 fixed to the end of the pipe to connect the pipe to the metal container 39. A flow path 39a is formed that diagonally penetrates the wall of the container 39 and opens to the inside of the container.As shown in FIG. The magnetic field H generated by code 6)
Since the area A occupied by the wave path figure on the outer wall of the container projected in the direction of the direction of the wave path is set so that the area B occupied by the projected figure of the wave path on the inner wall of the container does not overlap, When plasma tries to go upstream in the gas flow path, it must cross the magnetic field within this diagonal flow path. However, as mentioned above, plasma cannot move across the magnetic field. The range in which plasma can go up is up to the left end position of area B, and cannot go up beyond this range. FIG. 3 shows another embodiment of channel formation according to the present invention,
This embodiment is similar to the diagonal flow path 39 in the embodiment of FIG.
The diameter d of a is smaller than the diameter d of the flow path 37a having the same cross section as the raw material gas introduction pipe 33, and the efficiency of gas supply decreases. This shows another method. According to this embodiment, a large-capacity space 39c that temporarily receives the gas flowing out from the raw material gas introduction pipe 33 is formed on the outer wall side of the metal container 39 as a part of the flow path, and from this space in an oblique direction. A plurality of channels 39b are provided and opened to the inside of the metal container, thereby preventing a decrease in gas supply efficiency. Area B of the projected figure in the magnetic field direction at the inner wall surface position of the metal container of the flow path 39b and area A of the projected figure at the outlet of the raw material gas introduction pipe
and are separated from each other, the plasma in the metal container cannot go beyond the right end position of region B and enter in the direction of the raw material gas introduction pipe, as in the case of FIG. FIG. 4 shows still another embodiment of the flow path formation according to the present invention. 37.40 is omitted, and this embodiment shows an economical method of forming a flow path without reducing gas supply efficiency like the embodiment shown in FIG. A diagonal hole having an inner diameter d slightly larger than the outer diameter of the metal container 39 is provided in the wall of the metal container 39 to form a flow path 39d,
A source gas introduction pipe 33 is inserted into this hole, and this pipe is hermetically welded to the metal container 39. In this embodiment as well, since the area B of the magnetic field direction projection figure at the inner wall surface position of the metal container of the flow path 39d and the area AI of the projection figure at the outlet of the raw material gas introduction pipe are separated from each other, the plasma inside the metal container is Unless it crosses the magnetic field, it cannot reach the raw material gas introduction pipe, which prevents it from entering the introduction pipe. In the above embodiments, only the case where a diagonal straight pipe is formed as a flow path in which the projected figure at the outlet position of the raw material gas introduction pipe line and the projected figure at the inner wall surface position of the metal container do not overlap is shown. In the wave path formed between the outlet position of the raw material gas introduction pipe and the inner wall surface position of the metal container, the projected figures in the direction of the magnetic field of the cross section cut perpendicular to the magnetic field do not overlap (both the two positions are If it exists in the flow path, the flow path may be a combination of flow paths bent at right angles, or a flow path formed by bending a pipe into a curved shape, or the outlet of the raw material gas introduction pipe. Even if the projected figure at the position and the projected figure at the inner wall surface position of the metal container overlap, the plasma flowing up from the opening on the inner wall side of the metal container cannot reach the source gas introduction pipe unless it crosses the magnetic field. , plasma is reliably prevented from entering the pipe. [Effects of the Invention] As described above, according to the present invention, the outlet of the raw material gas introduction pipe and the inner wall surface of the metal container of the raw material gas, in which there are at least two positions where the projected figures in the direction of the magnetic field of a cross section cut perpendicular to the magnetic field generated by the magnetic field generating means for generating a magnetic field in the metal container do not overlap. Since the flow path has been formed, even if the plasma generated in the metal container tries to move upstream through this flow path in a direction where the magnetic flux density is sparse, it will not reach the outlet of the raw material gas introduction pipe. must move across the magnetic field, while plasma cannot move across the magnetic field, which prevents the plasma from entering the source gas introduction pipe, thereby causing the pipe to become The release of heavy metals from the stainless steel pipe to be formed is prevented, and the effect of preventing contamination of the thin film (and also preventing thermochemical deterioration of the stainless steel pipe itself due to temperature rise) can be obtained.

[Brief explanation of drawings]

FIG. 1 is a front cross-sectional view showing a first embodiment of a flow path formed based on the present invention, and FIG. 2 is an explanatory cross-sectional view showing how to give an inclination to an oblique flow path in the embodiment of FIG. FIG. 3 is a front sectional view showing a second embodiment of a flow path formed based on the present invention, and FIG. 4 is a front sectional view showing a third embodiment of a flow path formed based on the present invention. 5 is a longitudinal sectional view of the device showing an example of the configuration of a conventional dry thin film processing device, and FIG. 6 is the magnetic flux density distribution in the device “-1” for moving the plasma inside the metal container toward the substrate. 1: Waveguide (microwave transmission means), 3.31 Metal container, 4.31.33: Raw material gas introduction pipe, 6: Magnetic field generation means, 11: Substrate (sample), 37a, 39a, 39b+
Figure 1 Figure 2 Figure 4 Micro 22-45GHz Figure 5 Figure 6 Procedural amendment (voluntary) r゛゛May 1985 9B Japan Patent Office--Director-First Official-114←Kainitsu-Den 1 , Indication of the matter Patent application Sho ≦ / - Otsubokoshi - ζ 3, Person making the amendment Address related to the applicant's case 711; L, 'a Ichikawa use ++'jIA Yamabe new till 1-1 Name +5231 Fuji Electric Co., Ltd. (and other names) 4. Contents of the agent's amendment 1. Insert ``for example, made of aluminum'' between ``de'' and ``metal'' on page 3, line 14 of the specification. 2. On page 6 of the specification, line 3, "inside the pipe" is corrected to "pipe section." 3. Correct "exit" in line 11 of the same page to "exit section." 4. In line 16 of the same page, "pipe line" is corrected to "pipe section." 5. On page 8 of the specification, line 12, "exit" is corrected to "exit section." 6. On page 9 of the specification, line 9, "exit" is corrected to "exit section." 7. In the 12th line of the same page, "pipeline" is corrected to "pipeline section" in both places. 3. Correct "mouth" in the first line of page 11 of the specification to read "mouth part." 9. Figures 3 and 4 are shown in the attached sheet (corrected).

Claims (1)

[Claims] 1) means for generating microwaves, means for transmitting the microwaves, a metal container coupled to the microwave transmission means, and means for generating a magnetic field within the metal container;
a raw material gas introduction pipe for introducing a raw material gas into the metal container into which active atoms, molecules, or ions are formed in the metal container under the simultaneous action of the microwave and the magnetic field; In a dry thin film processing device that performs processing such as forming a thin film or etching on the surface of a sample using active atoms, molecules, or ions, the inner side of the metal container is connected to the outlet of the raw material gas introduction pipe. characterized in that a source gas flow path is provided which is open to the magnetic field generating means and has at least two positions where the projected figures of a cross section cut in a direction perpendicular to the magnetic field generated by the magnetic field generating means in the direction of the magnetic field do not overlap. Dry thin film processing equipment.