JP2003163203A - Semiconductor manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent yield lowering due to dust produced from a deposited matter of the inside of a vacuum chamber of a semiconductor manufacturing device. <P>SOLUTION: When light is introduced and taken in onto a transmission member by using an optical fiber, it is attached through an adapter for condensing light. Each face of the adapter attaching the optical fiber and the transmission member is an equal area to each cross section. Determination or the like of a cleaning period of the deposited matter accompanying releasing of atmospheric air facilitates since a composition of the deposited matter of the inside of the vacuum chamber and a relative film thickness can be analyzed by being attached to the semiconductor manufacturing device by using the adapter making light amount loss the minimum, and productivity of a semiconductor device can be improved. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of reducing light quantity loss and efficiently obtaining light quantity when introducing or extracting light using an optical fiber as a light-transmissive member. Application, and in particular, to a method for monitoring the state of reaction products formed in an apparatus.

[0002]

2. Description of the Related Art In a semiconductor manufacturing apparatus and the like, as a large number of wafers are processed, the amount of dust generated in the apparatus increases, the process becomes unstable, and the yield decreases. As a cause, reaction products are accumulated on the inner wall of the vacuum chamber and the surface of parts (hereinafter referred to as "deposited material"), and dust is generated from them, or the process is caused by some reason. It is believed to be unstable. In fact, when the processing chamber is opened to the atmosphere and the reaction products that are deposited are cleaned, the yield is recovered.

Therefore, monitoring the deposition process and deposition state of deposits is considered as one means for improving the yield of semiconductor device manufacturing and is being studied.

Therefore, as described in Japanese Patent Application Laid-Open No. 7-86254, there has been proposed a method of measuring the generation process and deposition state of deposits using a fiber. According to this, a member that transmits light is installed in the vacuum chamber, and light is introduced into the transparent member using an optical fiber or the like, and the reflected light is dispersed or the amount of light is measured to obtain a vacuum. The idea is to estimate the deposits in the chamber.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As described in JP-A-7-86254, when the deposition amount of deposits is analyzed using an optical fiber or the like, the optical fiber is changed to a translucent member. When introducing light, or conversely, when reflected light is taken into the optical fiber from the transmissive member, a light amount loss occurs. This is because light leaks out because the transparent member and the optical fiber have different areas. Since the area of the end face of the transparent member is about several tens of cm ² and the optical fiber is as thin as φ0.1 mm, the area where the optical fiber contacts the transparent member is only about 10 ⁻⁴ . That is, most of the light leaks out. This light amount loss is larger in the portion that is introduced into the transmissive member than in the portion that is introduced into the transparent member, and if a certain amount of light cannot be obtained, the deposit object cannot be analyzed.

[0006]

In order to solve the above-mentioned problems, it is necessary to prevent light from leaking during the process of introducing the optical fiber into the transparent member and taking the light from the transparent member into the optical fiber. Good.

For that purpose, an adapter is provided between the optical fiber and the transparent member. The surface of the adapter to which the optical fiber is attached has the same area as the cross section of the optical fiber, and the surface of the other adapter to which the transparent member is attached has the same area as the cross section of the transparent member. The adapter is shaped so that the light introduced into the adapter from the optical fiber and the light entering the adapter from the transparent member are totally reflected in the adapter. In addition, the entire surface of the adapter is made to have a surface roughness equal to or less than the wavelength λ of the light to be introduced to prevent irregular reflection of light. Then, the optical fiber may be previously fixed and integrated so that the amount of light is maximized between the optical fiber and the adapter.

By making the shape of the surface on which the adapter, the optical fiber and the transparent member are attached to have the same area as each cross section, it is possible to prevent light from leaking out. Further, since the adapter and the optical fiber are integrated and adjusted so that the light amount becomes maximum, the adjustment of the optical axis becomes unnecessary, and at the same time, the accuracy of mounting the optical fiber and the transparent member becomes easy. .

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIG.

Adapter 1 for attaching optical fiber 2
The surface a of the optical fiber 2 has the same area as the cross section of the optical fiber 2, and the other surface d to which the transparent member 16 is attached is the transparent member 1
The area is the same as the cross section of 6. The adapter 1 is introduced from the optical fiber 2 into the adapter 1 or the transparent member 1
It is necessary to form the light so that the light entering the adapter 1 from 6 is totally reflected in the adapter 1. In addition, the entire surface of the adapter must be made to have a surface roughness equal to or less than the wavelength λ of the light to be introduced to prevent irregular reflection of light. The material of the adapter 1 is quartz, sapphire, silicon, ZnSe, KRS-5, etc., and it is necessary to select a material that transmits light in the wavelength region of the absorption spectrum to be investigated.

The optical fiber 2 is attached to the surface a of the adapter 1. There are a method of inserting the optical fiber 2 itself into the adapter 1 and a method of attaching the connector 3 to the optical fiber 2 and then attaching to the adapter 1 as shown in FIG. Connector 3 is also made of quartz, sapphire, silicon, ZnS
e, KRS-5, etc., and the same material as the adapter 1. In the method of inserting the optical fiber 2 itself into the adapter 1, the optical fiber 2 may be directly fixed to the surface a of the adapter 1 with an adhesive b, or a hole c corresponding to the diameter of the optical fiber 2 may be formed. The optical fiber 2 may be attached there and fixed with the adhesive b. Even when the connector 3 is used, a hole c corresponding to the diameter of the optical fiber 2 may be formed in the connector 3 to fix the optical fiber 2. When fixing the optical fiber 2 to the surface a of the adapter 1, a light source 4 is used and a detector is attached to one side of the optical fiber 2 so that the amount of light becomes maximum.

By using this adapter 1, it is possible to prevent a light amount loss between the optical fiber 2 and the transparent member 16 and between the transparent member 16 and the optical fiber 2. Even if a slight deviation occurs when the adapter 1 is attached to the transmissive member 16, since the shape and area in which the adapter 1 and the transmissive member 16 contact each other are made equal, a large light amount loss does not matter. It should be noted that this facilitates the mounting accuracy of the optical fiber 2 and the transparent member 16 to facilitate the mounting of the semiconductor manufacturing apparatus in the vacuum chamber 6 at the production site, and the inner wall 14 of the vacuum chamber 6 and the transparent There is an effect that the deposit on the surface of the elastic member 16 can be easily analyzed.

A case where the above-described adapter 1 is used in a semiconductor manufacturing apparatus will be described with reference to FIGS. 3 and 4.

FIG. 3 is a schematic view of a reactive ion etching (hereinafter abbreviated as "RIE") apparatus using a magnetron in a semiconductor manufacturing apparatus. This magnetron RIE device rotates the magnetron 7 in the vicinity of the vacuum chamber 6 and supplies high-frequency power 8 into the vacuum chamber 6 to generate plasma 9 in the vacuum chamber 6 to etch the object 10 to be processed. Is.

Inside the vacuum chamber 6, a lower electrode 11 provided with a stage for mounting an object 10 to be processed such as a semiconductor wafer is installed. A ring-shaped magnetron 7 is rotatably arranged on the outer peripheral portion of the vacuum chamber 6. A high frequency power source 8 is connected to the lower electrode 11 via a matching unit (not shown).

In the vacuum chamber 6, a reaction gas 12, for example, hydrogen bromide 70 sccm, chlorine 20 sccm, oxygen 5 s
A mixed gas of ccm is supplied and the pressure is maintained at 6 Pa.
At the same time, a high frequency power of 400 W is supplied to the lower electrode 11 from the high frequency power supply 8 through a matching device. Further, the magnetron 7 on the outer peripheral portion of the vacuum chamber 6 rotates at a predetermined rotation frequency. As a result, plasma 9 is generated in the vacuum chamber 6 and chemically reacts with ions and radicals in the plasma 9 to etch the object 10 to be processed.

During the process of etching the object 10 to be processed,
A deposit 13 is formed on the inner wall of the vacuum chamber 6 and the surfaces of the constituent members. The deposit 13 increases as the etching process of the object 10 is repeated.

Next, a method of analyzing the deposit formed on the inner wall 14 of the vacuum chamber 6 will be described.

FIG. 4 is an enlarged sectional view of the inner wall 14 of the vacuum chamber 6. The embodiment of the present invention utilizes the transmission window 15 provided for detecting the light in the vacuum chamber 6, which is generally made of quartz glass.
The translucent member 16 is attached to the transmissive window 15. The permeable member 16 and the vacuum inside the vacuum chamber 6 may be sealed off using an O-ring 18 or the like. The material of the transparent member is, for example, quartz,
Sapphire, silicon, ZnSe, KRS-5, etc.,
The same material as the adapter 1 and the connector 3 is used. Then, the adapter 1 is attached.

Then, for example, when infrared light is introduced from the optical fiber 2, the deposit 1 formed on the surface of the transparent member 16
3 causes absorption in a specific wavelength region, so that the amount of light decreases in that wavelength region. Since the wavelength range in which infrared light is absorbed differs depending on the substance, the composition of the deposit 13 can be identified from the reduced wavelength range, and the relative thickness can be analyzed from the decrease in the amount of light. The detailed analysis method is described in JP-A-7-86254, and the analysis method in this example is also based on the same method.

Therefore, from this result, if a certain standard is set, it becomes possible to easily determine the cleaning time of the deposit 13 accompanied by opening of the apparatus to the atmosphere. Further, when it is known that the composition of the deposit 13 changes due to a leak in the vacuum chamber 6 or the like, it is possible to take immediate action by analyzing the deposit 13. In other words, by analyzing the deposit 13, it is possible to detect an abnormality such as a leak in the vacuum chamber 6 at an early stage and prevent a defect from being created due to the abnormality, which leads to an improvement in the productivity of semiconductor devices.

Although the embodiment of the present invention has been described with reference to the inner wall of the vacuum chamber 6 of the semiconductor manufacturing apparatus, it can be easily applied to the analysis of deposits attached to the surface of the piping of the exhaust system. Many deposits adhere to the surface of the piping of the exhaust system, and if left for a long time, it may cause troubles in the exhaust system or dust that contaminates the wafer. for that reason,
By creating a port for attaching the transparent member 16 to a part of the pipe, attaching it, and attaching the adapter 1 integrated with the optical fiber 2 to the transparent member 16,
It is possible to easily analyze the adhesion amount and composition without performing complicated adjustment of the optical axis. Therefore, it can be a means for investigating the timing of pipe replacement and the cause of sudden dust.

[0023]

EFFECTS OF THE INVENTION A vacuum is provided by attaching to a semiconductor manufacturing apparatus by using an adapter that minimizes a light amount loss when introducing light from an optical fiber into a transparent member and when taking in the light from the transparent member into the optical fiber. Since the composition of the deposits in the chamber and the relative film thickness can be analyzed, it is easy to determine the cleaning time of the deposits, which is accompanied by opening to the atmosphere, and the productivity of semiconductor devices can be improved. By using the adapter,
Since no complicated optical axis adjustment is required, anyone can use it easily, and it is easy to deploy to devices with different structures.

[Brief description of drawings]

FIG. 1 relates to a method of introducing and capturing light according to the present invention.

FIG. 2 relates to another method for introducing light and taking in light according to the present invention.

FIG. 3 is a schematic diagram of a reactive ion etching apparatus using a magnetron used in an example of the present invention.

FIG. 4 is a detailed view of mounting on a semiconductor manufacturing apparatus according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Adapter, 2 ... Optical fiber, 3 ... Connector, 4 ... Light source, 5 ... Detector, 6 ... Chamber, 7 ... Magnetron, 8
... High frequency power source, 9 ... Plasma, 10 ... Object to be processed, 11 ...
Lower electrode, 12 ... Reactive gas, 13 ... Deposition object, 14 ... Chamber wall, 15 ... Transmission window, 16 ... Transparent member, 17 ... Optical path, 18 ... O-ring, a ... Optical fiber and adapter mounting surface, b ... Adhesive, c ... hole, d ... Mounting surface of transparent member and adapter.

Continued front page    F term (reference) 2F065 AA30 CC00 FF44 FF46 GG02                       LL02                 2G059 AA01 BB08 CC01 EE01 EE02                       FF06 GG10 HH01 JJ17 JJ21                       LL02 NN06                 5F004 AA15 BA04 BB29 CB09 DA04                       DA26

Claims (6)

[Claims] 1. A method of introducing infrared light from an optical fiber to deposit on the inner wall of a vacuum chamber of a semiconductor manufacturing apparatus, the surface of a transparent member installed in the chamber, or the inner wall of an exhaust pipe. A semiconductor manufacturing measure characterized by being provided with an adapter capable of minimizing a light amount loss between the conductive members. 2. The adapter according to claim 1, wherein the surface where the optical fiber and the adapter contact each other has the same area as the cross section of the optical fiber, and the surface where the transparent member and the adapter contact each other have the same cross section as the transparent member. The semiconductor manufacturing equipment is characterized in that the light entering the adapter is totally reflected in the adapter. 3. The semiconductor manufacturing apparatus according to claim 1, wherein the adapter has a surface roughness of a wavelength λ or less to be introduced. 4. The light introduction detecting method according to claim 1, wherein the optical fiber and its adapter are integrated in advance. 5. The semiconductor manufacturing apparatus according to claim 1, wherein the semiconductor manufacturing apparatus is attached to an inner wall of an exhaust pipe of a vacuum exhaust system. 6. A semiconductor device produced by the method according to claim 1.