KR100475030B1 - Method of cleaning semiconductor manufacturing chamber with plasma - Google Patents

Abstract

A method of cleaning a chamber for manufacturing a semiconductor device using a plasma is disclosed. The present invention utilizes a chamber apparatus including a chamber and a Fourier transformed infrared spectrometer for dimming and receiving light within the chamber. A plasma is supplied to clean the chamber by reacting with the residue adsorbed on the inner wall in the chamber to remove the residue. The residue is removed by reaction of the plasma with the adsorption residue. The end point of the reaction is detected using a change in the absorption peak of the spectral spectrum according to the type and time behavior of the volatile by-products generated by the reaction obtained by the Fourier transform infrared spectrometer. In accordance with the detection of the reaction end point, the supply of the plasma to the chamber is terminated to terminate the cleaning of the chamber.

Description

A method of cleaning a semiconductor device manufacturing chamber using plasma {Method of cleaning semiconductor manufacturing chamber with plasma}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor devices, and more particularly to a method of effectively controlling a plasma process and cleaning the interior of a chamber of a chamber device with a plasma.

Among processes for manufacturing a semiconductor device, there is a process of coating or etching a film on a semiconductor substrate using plasma. This plasma process is performed by supplying plasma into the chamber of the chamber apparatus and reacting the plasma. In order to control the reaction of the plasma, a process of detecting the progress of the plasma reaction and the end point of the reaction is required. For example, it is required to accurately detect the end point of the etching reaction in the etching process using the plasma.

In addition, by-products of the reaction may remain in the chamber walls of the chamber chamber of the general chamber apparatus. Nonvolatile materials such as, for example, polymers may remain on the chamber walls. This residue becomes a detrimental effect on the reaction process running in the chamber. For example, it becomes an element causing particle generation. Accordingly, there is a further need for a process of periodically cleaning the inside of the chamber. Such a chamber cleaning method includes a wet cleaning method in which the chamber is opened and the inside thereof is directly wiped with a chemical solution. There is also a dry cleaning method that removes residues in the chamber using plasma.

However, the wet cleaning method requires disassembly of the chamber, which requires a downtime and is time consuming. Therefore, in general, the cleaning cycle is lengthened and is not frequently executed. And, the dry cleaning method is not easy to detect the degree of reaction by the plasma. That is, the reaction degree by the plasma cannot be known without opening the chamber. This makes it difficult to control the whole process. Therefore, difficulty in setting an appropriate cleaning time occurs.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a chamber cleaning method for manufacturing a semiconductor device that can detect a degree of reaction and an end point of a reaction during a process, facilitate process control, and do not require a process of opening a chamber. .

In order to achieve the above technical problem, the present invention provides a method for cleaning the inside of a chamber by using a plasma. First, a plasma is supplied into the chamber that reacts with a residue adsorbed on an inner wall of the chamber of the chamber apparatus including a chamber and a Fourier transform infrared spectrometer apparatus for dimming and receiving light in the chamber. Thereafter, the type and time behavior of the plasma reaction by-products caused by the reaction of the residue and the plasma are analyzed by the Fourier transform infrared spectrometer to control the reaction with the plasma to remove the residue. In the removing of the residue, the plasma reaction by-products may be analyzed by Fourier transform infrared spectroscopy using the Fourier transform infrared spectrometer apparatus to detect a reaction endpoint of the residue and plasma, and the reaction endpoint may be detected. By the method of terminating the supply of the plasma.

According to the present invention, when the chamber cleaning process using plasma is performed, the reaction end point can be accurately detected in situ, and the cleaning process control can be precisely controlled.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the illustrated members in the drawings are exaggerated to emphasize a more clear description, the elements denoted by the same reference numerals in the drawings means the same element.

1 schematically shows a chamber arrangement used in an embodiment of the invention.

Specifically, the chamber apparatus used in the present embodiment includes a chamber 100, a spectrometer, a plasma generator 300, a controller 400, and the like. In this case, the plasma generating device 300 generates the plasma 310 and serves to supply it into the chamber 100. That is, when plasma is supplied into the chamber 100, the plasma 300 supplied into the chamber 100 reacts to generate reaction by-products.

As the spectrometer, a device such as a Fourier Transformed Infrared Red spectrometer system (hereinafter referred to as "FTIR apparatus") is used. The FTIR device includes a light emitter 230, a light receiver 250, a monitor 200, and the like. The light 270 emitted from the light emitting unit 230 is dimmed into the chamber 100 through the light emitting window 210, and the light receiving unit 250 receives the light passing through the chamber through the light receiving window 215. Detect. The light received in this way is transmitted to the monitor part (200) to be converted into the FTIR spectrum (spectrum) and monitored. In the FTIR spectrum thus obtained, information such as the type of the reaction by-product and the time behavior of the reaction by-product can be detected. The monitor 200 may control the light emitter 250 to adjust an angle of light incident through the light emitting window 210 to receive an FTIR spectrum according to a reaction proceeding on the semiconductor substrate 110. ) Can be monitored. In addition, by adjusting the angle of the incident light, the state of the plasma 310 in the chamber 100 may be detected by monitoring the FTIR spectrum.

By transmitting the information detected by the monitor unit 200 to the controller 400 as described above, the controller 400 controls the reaction of the plasma 310 that proceeds in the chamber 100 based on the information. . For example, the end point of the reaction can be controlled by detecting the reaction endpoint based on the above information. That is, the endpoint of the reaction can be accurately detected based on the change in the FTIR spectrum of any one of the substances participating in the reaction. In addition, the supply of the plasma 310 to the chamber 100 may be terminated by controlling the plasma supply device 300 in the controller 400 at the same time as the reaction end point is detected. This completes the reaction. As such, the progress of the plasma reaction may be detected in situ, and process control such as the end of the process may be performed.

The method of detecting the information on the type and time behavior of the reaction by-products such as the reaction end point described above will be described in detail with an application example of a chamber cleaning method for removing residue deposited on the inner wall of the chamber 100. However, the present invention should not be construed as being limited thereto.

2 shows the FTIR spectra of the process by-products and the reaction by-products measured in situ.

Specifically, a chamber cleaning method for removing residues, for example, polymers, etc. deposited on the inner wall of the chamber 100 will be described as an application example of a process control method using plasma. First, the plasma 310 is supplied to the chamber 100. In this case, a case where the fluorocarbon (C _X F _Y ) -based polymer is adsorbed as a residue on the inner wall of the chamber 100 will be described as an example. The fluorocarbon-based polymer is a representative etching process byproduct and serves as a process reproducibility and particle source. Accordingly, an oxygen plasma (O ₂ plasma) capable of reacting with the fluorocarbon polymer is used as the plasma 310.

The oxygen plasma and the fluorocarbon polymer react with each other as shown in Equation (1). That is, a plasma reaction occurs that generates volatile gases such as COF ₂ and CO as reaction by-products. Accordingly, the reaction by-products are volatilized and the inner wall of the chamber 100 is cleaned. The FTIR spectrum of the reaction by-product measured in situ during the plasma reaction is shown in FIG. 2. The time shown in FIG. 2 represents the time after the oxygen plasma is supplied to the chamber 100, that is, after the oxygen plasma and the fluorocarbon polymer start the plasma reaction.

At this time, the kind of the reaction by-product can be known from the wavelength length at which the absorption peak appears. That is, in Figure 2 approximately 2183.435 cm ^-1 And absorption pits at wavelength lengths of 2108.673 cm ⁻¹ can be attributed to reaction byproducts of the CO species. It can also be seen that the absorption peak at a wavelength length of approximately 1929.219 cm ⁻¹ is due to the reaction byproducts of the _two COF species. This is due to the nature of the material inherent properties. In addition, it can be seen that the intensity of the absorption peak decreases as the time since the plasma reaction starts increases, and the absorption peak does not appear at the above-mentioned wavelength length in the FTIR spectrum measured after approximately 4 minutes.

As described above, the disappearance of the absorption peak of the reaction by-product indicates that the plasma reaction as in Equation 1 is terminated. That is, it can be seen that approximately 4 minutes after the start of the plasma reaction by supplying the plasma 310 into the chamber 100 is the end point of the reaction. The supply of the plasma 310 is stopped in response to the detection of the reaction end point, thereby controlling the process of using the plasma, that is, the chamber cleaning process. As such, the behavior of the reaction by-product as well as the type and time of the reaction endpoint can be analyzed and detected in-situ with the process progress.

The reaction endpoint as described above may be detected at different times depending on the adsorption thickness and amount of the residue. In addition, the kind of the residue, that is, the chemical composition of the polymer may vary. However, as described above, by detecting and analyzing the FTIR spectrum of the reaction by-product with the FTIR apparatus, it is possible to more precisely control the process in situ and in situ.

A process control method using a plasma according to an embodiment of the present invention has been described with an application example of a chamber cleaning method. However, examples of the application of the present embodiment may further include application to a dry etching method. Specifically, the semiconductor substrate 110 is introduced into a stage in the chamber apparatus as described with reference to FIG. 1. Thereafter, the plasma is supplied into the chamber 100. At this time, the plasma 310 is a plasma of a material capable of reacting with the semiconductor substrate 110 or the film formed on the semiconductor substrate 110 to be etched, for example, a fluorine (F) or chlorine (Cl) -based plasma I use it. The plasma 310 supplied as described above reacts with the semiconductor substrate 110 or the film to generate reaction byproducts. Accordingly, a dry etching process is performed.

Next, the FTIR apparatus analyzes and detects the type and time behavior of the plasma reaction by-products caused by the reaction between the semiconductor substrate 110 or the film and the plasma 310. In this way, the semiconductor substrate or the film quality is controlled and the semiconductor substrate is patterned. That is, the plasma reaction by-products are analyzed by the FTIR spectrum using the FTIR apparatus to detect the reaction end point with the plasma as described above. When the reaction end point is detected as described above, the supply of the plasma 310 is stopped to terminate the dry etching process.

In the above, the optimal embodiments have been disclosed in the drawings and the specification. Although specific terms have been used herein, they are used only for the purpose of clearly describing the present invention and are not intended to limit the scope of the present invention as defined in the meaning or the claims.

According to the present invention described above, by attaching the FTIR device to the chamber to proceed with the process in the chamber it is possible to detect the type and time behavior of the reaction by-product in situ. This enables more precise process control. For example, it is possible to accurately detect the reaction end point of the plasma in the chamber cleaning process, thus eliminating the step of opening the chamber and precisely controlling the cleaning process. In addition, in the process of dry etching the film quality formed on the semiconductor substrate or the semiconductor substrate, it is possible to accurately detect the plasma reaction end point, thereby realizing a more precise etching process.

1 is a view schematically showing a chamber apparatus used in a plasma process according to the present invention.

FIG. 2 is a graph showing Fourier transformed infrared red spectrum of the reaction by-products performed in plasma and the reaction by-product measured in situ.

Claims (1)

A plasma to clean the chamber by reacting with the residue adsorbed on the inner wall of the chamber in the chamber of the chamber including a chamber and a Fourier transform infrared spectrometer for dimming and receiving light in the chamber. Supplying; Removing the residue by the reaction; Detecting an end point of the reaction using a change in an absorption peak of the spectral spectrum according to the type and time behavior of the volatile by-products generated by the reaction obtained by the Fourier transform infrared spectrometer; And And terminating the cleaning of the chamber by terminating the supply of the plasma to the chamber in accordance with the detection of the reaction end point.