KR20000052118A - Method for Auto Scanning Wavelength of Semiconductor Etching Equipment - Google Patents

Abstract

PURPOSE: A method for automatically monitoring a wavelength of a semiconductor etching device is to improve an operation efficiency and to provide an easy data analysis. CONSTITUTION: An auto monitoring method of a wavelength of a semiconductor etching device having chamber, a wavelength detector, controller, and personal computer, comprises the steps of: controlling the wavelength detector by a process parameter for automatically monitoring a wavelength, downloaded from the personal computer, automatically monitoring a signal wavelength generated from the chamber, and transmitting the monitored wavelength data; and analyzing a quality and quantity of the substance in the chamber by comparing the monitored data with a specific wavelength stored in the database, displaying the analyzed data, and storing the same with a text file; and monitoring the displayed data, and correcting the wavelength detector when an error is detected.

Description

Method for Auto Scanning Wavelength of Semiconductor Etching Equipment

The present invention relates to semiconductor etching equipment, and more particularly, to a method for automatically detecting wavelengths of semiconductor etching equipment.

In general, most of semiconductor etching equipment performs time etching that performs etching for a set time according to the type of semiconductor. If this method is used, it is not possible to obtain the standard etching type as desired. do.

As illustrated in FIG. 1, the semiconductor etching apparatus having the above-described endpoint detection function includes a chamber 11 in which a wafer is mounted and a chemical reaction using a plasma is performed to perform etching, and the wafer chamber 11. Controlling the semiconductor etching process of the semiconductor etching apparatus 1 and the semiconductor etching apparatus 1 including a transfer module (not shown) which is mounted on or removed from the chamber 11. The main controller 5 and the light generated in the chamber 11 are input through the optical fiber and interfere with the length of the optical path by using diffraction of the reflector to convert only light having a specific wavelength into an electrical signal and amplify to an appropriate level. Or an end point of etching (hereinafter, referred to as an end point) of the wafer in the chamber 11 according to the wavelength detector 2 to attenuate and the built-in end point detection program. PC 4, which outputs a control signal for controlling the high wavelength detector 2, transmits the process parameter setting value to the wavelength detector 2 according to the control signal output from the PC 4 to receive only a predetermined wavelength or By controlling the diffraction angle of the reflector at regular intervals to enable Auto Scan, the analog electric signal output from the wavelength detector 2 is converted to digital and transmitted to the PC 4 and finally detected. It consists of the sub controller 3 which transmits an endpoint to the main controller 5.

In this case, the wavelength detector 2 may have a case in which the accuracy of the output data is lowered due to various reasons. In this case, the end detection is not properly performed, and as a result, accurate etching cannot be performed.

Therefore, the wavelength automatic search is performed as an operation for identifying and correcting an abnormality in the data output of the wavelength detector 2 before periodic or endpoint detection.

Referring to the wavelength automatic search and the end detection operation of the semiconductor etching equipment configured as described above are as follows.

First, the automatic wavelength search operation will be described. As described above, the automatic wavelength search operation is performed before the periodic or end point detection. The automatic wavelength search continuously changes the diffraction angle of the reflector in the wavelength detector 2 at a predetermined interval. In addition, the intensity of light for each wavelength is detected and the wavelength autodetection data is displayed on the screen as shown in FIG. 2.

Therefore, the operator compares the wavelength auto-detection data displayed on the screen with the intrinsic wavelength of the material and performs a calibration operation on the wavelength detector 2 so that an accurate search is performed when an abnormality is found.

In this case, if it is necessary to determine the type and amount of the material in the chamber 11, it cannot be performed by itself, and it is necessary to use a separate optical emission spectroscopy equipment.

Next, the end point detection operation will be described. As described above, the end point detection operation is started in the state where the automatic wavelength detection is completed. As the etching process under the control of the main controller 5 proceeds, the plasma generated in the chamber 11 is generated. By this, light having a predetermined wavelength is generated.

Subsequently, the light is transmitted to the wavelength detector 2 through the optical fiber, and the wavelength detector 2 controls the diffraction angle of the reflector under the control of the sub-controller 3 to receive only a specific wavelength and converts it into an analog electric signal again. Transfer to the sub controller 3.

The sub-controller 3 converts the analog electric signal into digital and transmits it to the PC 4, and the PC 4 displays the data on the screen and detects the end point according to the built-in end point detection program.

At this time, the end point detection operation is performed by the end point parameter shown on the left side of FIG. 3. (Slope End), Window Width, and the like, and in particular, slope start, slope and two parameters serve as main elements of endpoint detection.

The digital signal input to the PC 4 via the wavelength detector 2 and the sub-controller 3 is displayed, as shown in the right side of FIG. 3, with the intensity of light of a specific wavelength increasing as the initial etching process starts. As time goes by, it shows a form that maintains a certain level with a slight fluctuation, and at a certain point, it decreases rapidly and approaches the end point.

That is, the etching of the specific portion is almost completed, so that the corresponding gas generation is reduced and thus the intensity of light having a specific wavelength is reduced.

At this time, the window, which is the basic unit for detecting the end point, is always set so that signal input is made in the middle. First, the slope start is a case where the signal output is recognized as the slope start when the signal output is made to the lower end in the number of consecutive windows. Since the slope start parameter of FIG. 3 is set to two windows, two or more windows in which a signal is outputted to the lower end as shown in part 'A' of FIG. 3 are recognized as slope start.

In addition, the slope end is a case of recognizing the slope end when the output of the signal does not pass through the lower end in the number of consecutive windows set by the parameter. Since the slope end parameter of FIG. 3 is set to three windows, the 'B' of FIG. As shown in the figure, three or more windows in which the signal output does not pass the bottom end are recognized as slope ends.

Therefore, when the end point is detected in this manner, the PC 4 stores the end point data in the form of a predetermined file and transmits it to the sub controller 3.

Subsequently, the sub controller 3 transmits the end point data to the main controller 5 so as to determine the end point of etching and to complete the etching.

However, the wavelength automatic detection method of the semiconductor etching apparatus according to the prior art has the following problems.

First, since the optical analysis operation cannot be performed by itself and requires the use of a separate optical analysis equipment, work efficiency is reduced because it is inconvenient and cannot be made in real time.

Second, since the storage format of the detection data is not easy to edit, limited to specific information, and does not conform to the semiconductor communication standard (SECS Protocol), it is difficult to utilize data.

Third, the wavelength detector measures the signal strength and automatically amplifies the signal to an appropriate level. At this time, the noise may be amplified as well, thereby reducing the reliability of the signal.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, to perform optical analysis when the wavelength automatic search and to store various data in the form of easy-to-edit data file to improve the work efficiency and data utilization It is an object of the present invention to provide a method for automatically detecting a wavelength of a semiconductor etching device.

The present invention provides a method of controlling a wavelength detector according to a process parameter for automatically searching wavelengths downloaded from a PC in a controller to automatically search for signal wavelengths generated in a chamber within a range set in process parameters and to transmit the found wavelength data to a PC. Analyzing the type and amount of the material in the chamber by comparing the wavelength data with the material-specific wavelength stored in the database on the PC, displaying the analysis data along with the wavelength data on the screen and storing it in the form of a text file. And inspecting the wavelength data displayed on the screen, and correcting the wavelength detector when an output abnormality is found.

1 is a block diagram showing an end point detection apparatus of a general semiconductor etching equipment;

2 is a graph showing an example of wavelength automatic search data output according to the related art.

3 is a graph illustrating an endpoint detection method according to the related art.

4 is a flowchart illustrating a method for automatically detecting a wavelength of a semiconductor etching apparatus according to the present invention.

5 is a graph showing an example of output of wavelength automatic search data according to the present invention;

6 is a view showing an example of a data file generated by automatic wavelength search

Explanation of symbols for main parts of the drawings

1: semiconductor etching equipment 2: wavelength detector

3: subcontroller 4: PC

5: Main Controller 11: Chamber

Hereinafter, a preferred embodiment of a method for automatically detecting a wavelength of a semiconductor etching apparatus according to the present invention will be described with reference to the accompanying drawings.

4 is a flowchart showing a method for automatically searching wavelengths of a semiconductor etching apparatus according to the present invention, FIG. 5 is a graph showing an example of output of wavelength auto searching data according to the present invention, and FIG. 6 is a data file generated by wavelength auto searching. Figure 1 shows an example.

As shown in FIG. 4, the method for automatically detecting a wavelength of a semiconductor etching apparatus according to the present invention is performed prior to the periodic or end point detection under the control of the PC 4. The process parameter (Recipe) is downloaded (DownLoad) to receive (S21).

Subsequently, the sub-controller 3 controls the wavelength detector 2 according to the process parameter downloaded from the PC 4 so that the automatic wavelength search is performed from the minimum wavelength to the maximum wavelength range (S22).

Accordingly, the wavelength detector 2 changes the diffraction angle of the reflector at regular intervals so that the search is performed within the wavelength range, and performs the search to convert the light intensity into an analog electric signal.

At this time, the output of the wavelength detector (2) is output without going through an amplification process, which is to prevent the amplification of noise components that have been presented as a problem of the prior art.

The sub-controller 3 converts only the actual wavelength data from which the noise component is excluded from the output of the wavelength detector 2 to the PC 4 by using an auto scale function.

Subsequently, the PC 4 compares the wavelength data with the wavelengths inherent in the material stored in the database and performs an optical analysis for identifying the type and amount of the corresponding material to simultaneously display the wavelength data and the optical analysis data as shown in FIG. 5 (S23). , It is stored in the form of a text file as shown in FIG. 6 (S24).

Subsequently, the operator looks at the display contents and compares the output data of each wavelength with the intrinsic wavelength of the material to calibrate the wavelength detector 2 when an abnormality occurs (S25).

In this case, the operator may zoom in and analyze the desired portion of the data displayed on the screen in detail using the zoom function.

Subsequently, as the semiconductor etching process is started, an end point detection operation is performed in the same manner as in the prior art, and an analog electric signal having a corresponding wavelength is output from the wavelength detector 2 according to the end point detection parameter.

The signal is amplified, digitally converted, and input to the PC 4 through the auto scale function of the sub-controller 3.

Subsequently, the PC 4 adjusts the width of the window in units of time according to the end point detection program and the end point detection parameter, detects the slope start and the slope end, and completes the end point detection.

The endpoint data is transmitted to the main controller 5 so that accurate etching is performed.

In addition, the PC 4 stores the endpoint detection data together with the corresponding parameters in the form of a text file to facilitate post data analysis.

The automatic wavelength detection method of the semiconductor etching apparatus according to the present invention has the following effects.

First, the automatic optical analysis is performed based on the wavelength auto-detection data and simultaneously displayed together with the wavelength data, thereby improving work efficiency.

Second, since wavelength data and endpoint detection data are displayed in real time and stored in the memory of a PC along with the relevant process parameters in the form of a text file, data can be easily edited and shared, as well as rapid data analysis. The utilization is also high.

Third, since the signal level is not amplified at the output of the wavelength detector, only an actual signal component without noise component is amplified to an appropriate level by using the auto scale function, thereby improving signal reliability.

Fourth, detailed data analysis is possible by adding data zoom function.

Claims (1)

In a semiconductor etching apparatus having a chamber, a wavelength detector, a controller and a PC, Controlling a wavelength detector according to a process parameter for automatic search of a wavelength downloaded from a PC in the controller to automatically search for a signal wavelength generated in the chamber within a range set in the process parameter and to transmit the searched wavelength data to the PC; Comparing the wavelength data with a material-specific wavelength stored in a database in a PC to analyze the type and amount of the material in the chamber, and display the analysis data along with the wavelength data on a screen and in the form of a text file; A method for automatically detecting a wavelength of a semiconductor etching apparatus, comprising: calibrating a wavelength detector when an output abnormality is detected by an operator inspecting wavelength data displayed on a screen.