Plasma CVD device

Abstract

To suppress adhesion of dirt to a glass window provided to a monitoring port of a plasma CVD device.SOLUTION: A monitoring port 16 is connected to a film deposition chamber 14 and is provided with a glass window 18. A radiation thermometer 20 measures a temperature in the film deposition chamber 14 through the glass window 18. An electromagnetic coil 22 is installed to the monitoring port 16. Electric current is supplied to the electromagnetic coil 22, and thereby the electromagnetic coil 22 generates a magnetic field 24 around the monitoring port 16.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a plasma CVD apparatus. [Background technology]

[0002] Patent Document 1 describes a plasma CVD (Chemical Vapor Deposition) apparatus. A radiation thermometer is provided in the plasma CVD apparatus. The radiation thermometer measures the temperature in the film formation chamber through a glass window via a monitoring port. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-190462 Summary of the Invention [Problem to be solved by the invention]

[0004] Since the radiation thermometer measures the temperature inside the film formation chamber through a glass window via a monitoring port, dirt on the glass window (for example, dirt caused by ions generated during film formation) can cause measurement errors. Nitrogen purging can be considered to prevent dirt from adhering to the glass window, but this does not necessarily mean that the adhesion of dirt can be prevented. Increasing the purge flow rate affects the film formation processing conditions, so the purge flow rate cannot be increased indiscriminately. In addition, since the radiation thermometer measures the light emitted from the measurement target, applying a substance that blocks specific wavelengths (for example, an anti-fouling coating) to the glass window will cause measurement errors.

[0005] An object of the present disclosure is to suppress adhesion of dirt to a glass window provided in a monitoring port of a plasma CVD apparatus. [Means for solving the problem]

[0006] One aspect of the present disclosure is a plasma CVD apparatus comprising: a film formation chamber; a monitoring port connected to the film formation chamber and equipped with a glass window; a radiation thermometer that measures the temperature inside the film formation chamber through the glass window; and an electromagnetic coil provided in the monitoring port, the electromagnetic coil generating a magnetic field around the monitoring port when a current is supplied to the electromagnetic coil. Effect of the Invention

[0007] According to the present disclosure, it is possible to suppress adhesion of dirt to a glass window provided in a monitoring port of a plasma CVD apparatus. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing a CVD apparatus according to an embodiment. [Diagram 2] FIG. 11 is a cross-sectional view showing a CVD apparatus according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A CVD apparatus 10 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a cross-sectional view showing the CVD apparatus 10.

[0010] The CVD apparatus 10 is a plasma CVD apparatus that converts a reactive gas into plasma to generate activated ions and form a thin film on a target object (eg, a substrate).

[0011] The CVD apparatus 10 includes a chamber 12, a film formation chamber 14, a monitoring port 16, a glass window 18, a radiation thermometer 20, and an electromagnetic coil 22. The configuration other than the electromagnetic coil 22 is the same as that of a known CVD apparatus.

[0012] The film formation chamber 14 is formed in the chamber 12. A vacuum is maintained inside the film formation chamber 14. An object such as a substrate is placed in the film formation chamber 14. A reactive gas is turned into plasma in the film formation chamber 14, whereby activated ions are generated and a thin film is formed on the object. For example, a film of carbon or the like is formed on the object. There is no limitation on the material to be formed into a film.

[0013] The monitoring port 16 is a cylindrical member that penetrates the wall of the chamber 12 and is connected to the film formation chamber 14. A vacuum is maintained inside the monitoring port 16. A glass window 18 is provided at one end of the monitoring port 16 (the end opposite to the end on the film formation chamber 14 side). A radiation thermometer 20 is provided outside the monitoring port 16 facing the glass window 18, and measures the temperature inside the film formation chamber 14 through the glass window 18.

[0014] The electromagnetic coil 22 is wound around the side surface (outer wall surface) of the monitoring port 16. When a current is supplied to the electromagnetic coil 22, the electromagnetic coil 22 generates a magnetic field 24 around the monitoring port 16. In Fig. 1, the direction of the magnetic field 24 is represented by an arrow.

[0015] As the film is formed, ions 26 (e.g., carbon ions C+) are generated in the film formation chamber 14. The ions 26 float in the film formation chamber 14 and the monitoring port 16. The ions 26 move randomly and cause contamination of the glass window 18. If the ions 26 adhere to the glass window 18, a measurement error in the radiation thermometer 20 may occur.

[0016] In this embodiment, the Lorentz force generated by the magnetic field 24 causes the ions 26 that have entered the monitoring port 16 to be guided to the inner wall of the monitoring port 16 (for example, the ions 26 are pushed toward the inner wall) before reaching the glass window 18, and to adhere to the inner wall. This makes it possible to prevent the ions 26 from adhering to the glass window 18. As a result, it is possible to reduce the measurement error of the radiation thermometer 20. The theory behind this is explained below.

[0017] The Lorentz force F that a charged particle experiences in a magnetic field with magnetic flux density B is expressed by the following equation (1). F = Q(v × B) (1) Q is the charge that the charged particle has. v is the velocity of the charged particle. F, v, and B are vector quantities.

[0018] When the monitoring port 16 has a cylindrical shape, the equation of motion in the diameter direction is expressed by the following equation (2). ma = F, a = QvB / m (2) m is the mass of the charged particle. a is the acceleration of the charged particle. a, F, v, and B are vector quantities.

[0019] The length of the magnetic field section is defined as length L, and the diameter of the monitoring port 16 is defined as diameter A. Furthermore, the time it takes for a charged particle to move through a section of length L is defined as time tL, and the time it takes for a charged particle to move through a section of diameter A is defined as time tA. Time tL is expressed by the following equation (3), and time tA is expressed by the following equation (4). Time tL=L / v (3) Time tA=sqrt(2Am / QvB)...(4)

[0020] If the arrival time of the diameter A is faster than the arrival time of the length L, the charged particles will not reach the glass window 18. Therefore, the length L, the diameter A, and the magnetic flux density B are designed so that the relationship of time tL > time tA holds.

[0021] According to this embodiment, there is no effect on the film formation conditions because no purge gas is introduced into the film formation chamber 14. In addition, the Lorentz force due to the magnetic field 24 does not interfere with light, so there is no effect on the measurement by the radiation thermometer 20.

[0022] A CVD apparatus 10A according to a modified example will be described below with reference to Fig. 2. Fig. 2 is a cross-sectional view showing the CVD apparatus 10A.

[0023] The CVD apparatus 10A includes magnets 28 and 30 instead of the electromagnetic coil 22. For example, the magnet 28 is a north pole magnet, and the magnet 30 is a south pole magnet. The magnets 28 and 30 are provided on the outer wall of the monitoring port 16 facing each other.

[0024] The magnets 28 and 30 form a magnetic field 32 in the monitoring port 16, directed from the magnet 28 to the magnet 30. This generates a Lorentz force in the monitoring port 16, acting in the direction of the inner wall of the monitoring port 16. The Lorentz force in the direction of the inner wall acts on the ions 26 moving toward the glass window 18. The ions 26 subjected to the Lorentz force are guided to the inner wall of the monitoring port 16 before reaching the glass window 18, and adhere to the inner wall. As a result, the ions 26 can be prevented from adhering to the glass window 18. [Explanation of symbols]

[0025] 10 CVD apparatus, 12 chamber, 14 deposition chamber, 16 monitoring port, 18 glass window, 20 radiation thermometer, 22 electromagnetic coil, 28, 30 magnet.

Claims

[Claim 1] A deposition chamber; a monitoring port connected to the deposition chamber and having a glass window; a radiation thermometer for measuring a temperature inside the film formation chamber through the glass window; and an electromagnetic coil provided in the monitoring port, the electromagnetic coil generating a magnetic field around the monitoring port when a current is supplied thereto; A plasma CVD apparatus comprising:

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