KR20070050149A - Monochrometer and end point detection system using the monochrometer of semiconductor production device - Google Patents

Abstract

The present invention provides a monochromator and an endpoint detection system using the monochromator to digitally adjust the numerical value of the wavelength of light for detecting an etch end position (EPD) during the etching process in a semiconductor manufacturing facility. It is about.

The monochromator of the semiconductor manufacturing equipment of the present invention for this purpose, the up button for generating a key signal for increasing the numerical value for the wavelength band of light, and the key signal for reducing the numerical value for the wavelength band of light A down button, a control unit for controlling the display to increase or decrease a numerical value for the wavelength band of light according to the operation of the up button and the down button; and a numerical value for the wavelength band of light under the control of the controller. And an LCD display unit for displaying.

In the semiconductor manufacturing etching apparatus, the numerical value of the wavelength of light is digitally adjusted by using an up button or a down button to prevent an error that the numerical value of the wavelength of light cannot be adjusted.

Endpoint, membrane wavelength recognition, monochromator, wavelength band of light

Description

MONOCHROMETER AND END POINT DETECTION SYSTEM USING THE MONOCHROMETER OF SEMICONDUCTOR PRODUCTION DEVICE}

1 is a block diagram of a conventional endpoint detection system

2 is a block diagram of the EPD monochromator 22 in FIG.

3 is a block diagram of an endpoint detection system according to an embodiment of the present invention.

4 is a block diagram of a device for displaying numerical values of wavelength bands of light formed in the monochromator 50 of FIG.

       Explanation of symbols on the main parts of the drawings

30: process chamber 32: wafer

34: Chuck 36: EPD Window

38: gas inlet pipe 40: viewport

42: optical cable 50: monochromator

52: LCD Display 54: Up Button

56: down button 58: hold button

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endpoint detection system of a semiconductor fabrication facility, and more particularly, to a digital method for digitally adjusting a numerical value of a wavelength of light for detecting an etch end position (EPD) during an etching process in a semiconductor fabrication facility. The present invention relates to an endpoint detection system using a chromometer and its monochromator.

Typically in semiconductor manufacturing processes, semiconductor, dielectric, and conductor materials, such as polysilicon, silicon dioxide, and aluminum layers, are deposited on the substrate to form patterns of gates, vias, contact holes, or interconnect lines. Is etched. Each layer of material is typically formed by chemical vapor deposition (CVD), physical vapor deposition, or oxidation and nitriding processes. For example, in a CVD process, the reactive gas is decomposed to deposit a material layer on the substrate and in the PVD process the target is sputtered to deposit the material on the substrate. In the oxidation and nitriding process, the oxide layer or nitride layer is typically formed with a silicon dioxide layer or silicon nitride layer on the substrate. In the etching process, a patterned mask layer or a hard mask of photoresist is formed on the substrate by a photolithographic method so that the exposed portion of the substrate is etched by an activated gas such as Cl 2, HBr or BCl 3.

In such a process, it is required to stop the processing of the substrate at a predetermined stage. For example, it is difficult to stop the etching process after etching only a thin layer of the substrate in a conventional etching process. As an example, in etching a gate structure, it is desirable to etch the remaining thickness of the lower gate oxide layer as close to the predetermined and acceptable value as possible so that the etching process does not damage any underlying polysilicon or silicon. The gate oxide layer becomes thinner and thicker in the fabrication of high speed integrated circuits, making it difficult to accurately etch the top polysilicon layer without overetching the bottom gate oxide layer.

As another example, it is desirable to form a layer having a controlled and predetermined thickness in the deposition, oxidation, and nitriding processes, and to stop the process precisely once a layer of desired thickness is obtained.

However, the thickness of the material layer to be etched on the wafer is not always constant throughout the wafer due to the step, etc., and the etching operation is not even evenly over the entire surface of the wafer. Therefore, sufficient time must be devoted to the process to fully etch the desired layer of material in the desired portion.

Therefore, in plasma etching during semiconductor manufacturing, in addition to the method of advancing the process for a predetermined time, a method of changing the etching conditions by finding a specific time point of the process is used. That is, before the specific time point, the process is selected by selecting a condition that can increase the etching rate, and after the specific time point, the process is performed by selecting a condition having a high selectivity with the lower layer even though the etching rate is low.

In this case, the specific time point of the process refers to a time point at which the film quality of the lower portion of the material layer to be etched is revealed, and finding this time point is called end point detection (EPD). The process before this time is called Main Etch, and the etching process after this time is called Over Etch.

The EPD method plays an important role in the etching method divided into these steps. There are many methods of EPD, but there are many ways to measure the emission from plasma in the process chamber using a monochromator and to find out if the wavelength inherent to a specific material is detected as a peak if possible. Used. END POINT DETECTION methods are used to measure the endpoint of an etch, deposition, oxidation or nitriding process. Endpoint measurement methods can be performed by analyzing the emission spectrum of plasma formed in the chamber by determining the change in chemical composition corresponding to the composition change of the layer being etched, for example, as indicated in US Pat. No. 4,328,068, which is incorporated herein by reference. Plasma emission analysis.

As another example, as another example referred to herein, US Pat. No. 5,362,256 monitors plasma emission intensity at selected wavelengths and displays remaining film thickness, etch rate, etch uniformity, and variation in etch endpoint and plasma emission intensity. A method of monitoring the etching or deposition process in connection with this disclosure is disclosed. Ellipsometry is another endpoint detection system that is useful for measuring process endpoints before the entire layer is processed. In this method, the polarization beam is reflected at the surface of the layer being etched and analyzed by measuring the phase shift and change in the magnitude of the reflected light that occurs as the layer is etched, which is described in U. S. Patents 3,974, 797 and 3,824,017. A polarizing filter is used to measure the phase change of the polarizing beam reflected at the surface of the substrate.

Another endpoint detection method is interferometry. An exemplary method is disclosed in US Pat. No. 4,618,262 to Maydan, which is incorporated herein by reference, which discloses a laser interferometer for directing a laser beam onto a layer to be processed on a substrate. The laser and associated monitoring system provide a reflectance curve measured according to the layer being processed. The computer calculates whether the preselected etch depth is reached by calculating the maximum or minimum number of reflectance signals or by recognizing the end of the etch process based on the cessation of the signal.

1 is a structural diagram of a conventional endpoint detection system.

In the chamber 16 in which the wafer 10 is etched, a chuck 12 is installed so that the wafer 10 is seated, and a gas inlet pipe 14 into which the reaction gas required for etching flows is provided at one side of the chamber 16. Is installed.

The chamber 16 is provided with an EPD window 15 which transmits light while separating the inside and the outside. EPD system 24 is a view port (18), which is the point where the light from the EPD window 15 is incident, and an optical cable for transmitting the light entering the view port 18 to the EPD monochromator 22 It consists of 20.

The EPD monochromator 22 filters light through an interference filter and then amplifies it to detect / etch a specific wavelength.

FIG. 2 is a configuration diagram of the EPD monochromator 22 in FIG. 1.

The control lever 101 for adjusting the numerical value of the band of the wavelength of light, the analog indicator 102 for displaying the numerical value of the wavelength of light according to the adjustment of the control lever 101, and the wavelength of the light. It is composed of a hold bar (103) for fixing the numerical value so as not to change.

In the semiconductor etching equipment, a monochromator 22 is used to detect the wavelength of the chip generated during etching and to detect the end point of the etching. The monochromator 22 used in the semiconductor etching process detects the wavelength of light generated when etching the film quality of the wafer surface using plasma and RF power, and detects the wavelength of the detected light as an endpoint detection system (EPD). : END POINT DETECTION SYSTEM) to help the EPD system 24 determine the change of film quality to determine the end point of etching. When the engineer rotates the control lever 101 to match the wavelength of light corresponding to the film quality of the wafer surface, the numerical value of the wavelength of light in the analog indicator 102 is changed. For example, if the engineer turns the control lever 101 counterclockwise, the numerical value for the wavelength of light decreases, and if the engineer turns the control lever 101 clockwise, the numerical value for the light wavelength increases. The hold bar 103 holds the numerical value for the wavelength of light currently displayed on the analog indicator 102 even if the engineer turns the control lever 101.

The conventional monochromator as described above is formed to rotate the control lever 101 by dialing, so that when used for a long time, the speed of change of the analog indicator 102 is reduced or the numerical value is not changed due to abrasion. There was a problem that could not be detected.

Accordingly, an object of the present invention is to solve the above problems, and to solve the above problem, the mono-point of the endpoint detection system that digitally adjusts the numerical value of the wavelength of light in the endpoint detection system to prevent the error of not detecting the wavelength of light. In providing a chromameter.

An endpoint detection system of a semiconductor manufacturing apparatus of the present invention for achieving the above object is an EPD window for transmitting the light while separating the inside and the outside of the chamber, a view port through which the light from the EPD window is incident, and the view An optical cable for transmitting the light entering the port to the EPD monochromator, and an up / down button and an LCD display unit to display a numerical value for the wavelength range of light according to the operation of the up / down button. And an EPD monochromator for detecting a wavelength corresponding to the numerical value among the wavelengths of light incident through the optical cable.

The EPD monochromator preferably includes a hold button for holding a numerical value for the wavelength band of light.

The monochromator of the semiconductor manufacturing equipment applied to the present invention for achieving the above object, the up button for generating a key signal to increase the numerical value for the wavelength band of light, and decreases the numerical value for the wavelength band of light A down button for generating a key signal, a control unit for controlling the display to increase or decrease a numerical value for the wavelength of light according to the operation of the up button and the down button, and a wavelength of light under the control of the control unit. And an LCD display for displaying a numerical value for the band.

And a hold button for generating a hold mode key signal and a hold mode release key signal for holding the numerical value of the wavelength solution of light so as not to change.

The control unit controls to hold the numerical value of the wavelength of light currently displayed when the hold mode key signal of the hold button is not changed.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

3 is a block diagram of an endpoint detection system according to an exemplary embodiment of the present invention.

A chamber 30 for performing an etching process by plasma in a vacuum state in the vacuum state, a chuck 34 installed in the chamber 30 to allow the wafer 32 to be seated, and a chamber 30 of the chamber 30. On one side, the gas inlet pipe 38 into which the reaction gas required for etching is introduced, the EPD window 36 for transmitting light while separating the inside and the outside of the chamber 30, and the light from the EPD window 36 is provided. An incident view port 40, an optical cable 42 for transmitting the light entering the view port 40 to the EPD monochromator 50, up / down buttons 54, 56 and hold A button 58 and an LCD display unit 52 are provided to display a numerical value for the wavelength band of light on the LCD display unit 52 according to the operation of the up / down buttons 54 and 56. 42 detects a wavelength corresponding to the numerical value among the wavelengths of the light incident through the detector, and converts the detected wavelength of the light into an endpoint detection system ( EPD: END POINT DETECTION SYSTEM (60) is composed of an EPD monochromator (50) that serves to determine the end point of the etching by determining the film quality change in the EPD system.

4 is a block diagram of an apparatus for displaying numerical values of wavelength bands of light formed in the monochromator 50 of FIG.

An up button 54 for generating a key signal for increasing a numerical value for the wavelength band of light,

A down button 56 for generating a key signal for reducing a numerical value for the wavelength band of light,

A hold button 58 for generating a hold mode key signal and a hold mode release key signal for holding the numerical value of the wavelength solution of light not to be changed;

When the up button 54 and the down button 56 are operated, the numerical value of the wavelength band of light is increased or decreased to control the display, and when the hold mode key signal of the hold button 58 is generated. A control unit 59 which holds the numerical value of the wavelength of light currently displayed so as not to change;

 The control unit 59 constitutes an LCD display unit 52 which displays numerical values for the wavelength band of light.

3 and 4 will be described in detail the operation of the preferred embodiment of the present invention.

In the chamber 30 in which the wafer 32 is etched, a chuck 34 is installed to seat the wafer 32, and a gas inlet pipe 38 into which a reaction gas necessary for etching flows is provided at one side of the chamber 30. Is installed.

The chamber 30 is provided with an EPD window 36 that transmits light while isolating the inside and the outside. The chamber 30 is provided with an EPD window 36 that transmits light while isolating the inside and the outside. The EPD system 60 is a view port 40, which is a point at which light from the EPD window 36 is incident, and an optical cable for transmitting the light entering the view port 40 to the EPD monochromator 50. It consists of 42.

The EPD monochromator 50 has an up button 54 for generating a key signal for increasing the numerical value for the wavelength band of light, and a down button for generating a key signal for decreasing the numerical value for the wavelength band of light. 56, a hold button 58 for generating a hold mode key signal and a hold mode release key signal for holding the numerical value of the wavelength solution of light unchanged, and the up button 54 and the down button 56 Control the display to increase or decrease the numerical value for the wavelength range of the light according to the manipulation of), and when the hold mode key signal of the hold button 58 is generated, the numerical value for the currently displayed light is changed. And a control unit 59 for holding it, and an LCD display unit 52 for displaying a numerical value for the wavelength band of light under the control of the control unit 59.

The engineer presses the up button (UP) 54 or the down button (DOWN) 56 to match the wavelength of light corresponding to the film quality of the wafer surface. Each time the up button 54 is pressed, the numerical value for the wavelength band of light increases by one, and each time the down button 56 is pressed, the numerical value for the wavelength band of light decreases by one. When the up button 54 or the down button 56 is pressed, the controller 59 controls the LCD display 52 to increase or decrease the numerical value for the wavelength of light by one. When the engineer presses the hold button 58, the controller 59 does not change the numerical value for the wavelength of light currently displayed on the LCD display 52 even when the up button 54 or the down button 56 is pressed. Hold to prevent.

As described above, in the present invention, the engineer manipulates the up button 54 or the down button 56 to display the numerical value for the wavelength of light corresponding to the film quality of the wafer surface so that the engineer can display the numerical value for the wavelength of the light on the LCD display unit 52. In the conventional dialing method, an error of failing to adjust a numerical value for a wavelength of light due to wear due to prolonged use can be solved in the present invention.

As described above, the present invention digitally adjusts the numerical value of the wavelength of light in the etching apparatus for semiconductor manufacturing by using the up button or the down button, and the numerical value of the wavelength of light due to wear caused by long time use in the mechanical dial method. There is an advantage to avoid errors that prevent you from adjusting the value.

Claims (4)

In the endpoint detection system of a semiconductor manufacturing facility, EPD window that transmits light while separating the inside and outside of the chamber, A viewport through which light from the EPD window is incident; An optical cable for transmitting the light entering the viewport to an EPD monochromator, An up / down button and an LCD display unit to display a numerical value for the wavelength band of light according to the operation of the up / down button, and to display the numerical value of the wavelength of light incident through the optical cable; And an EPD monochromator for detecting a wavelength corresponding to the endpoint detection system of the semiconductor manufacturing equipment. The method of claim 1, The EPD monochromator further comprises a hold button for holding a numerical value for the wavelength band of light. In the monochromator of the semiconductor manufacturing equipment, An up button that generates a key signal that increases a numerical value for the wavelength band of light, A down button for generating a key signal for reducing the numerical value for the wavelength band of light; A control unit which controls to increase or decrease the numerical value for the wavelength band of light according to the operation of the up button and down button;  And a LCD display unit for displaying a numerical value for the wavelength range of light under the control of the control unit. The method of claim 3, And a hold button for generating a hold mode key signal and a hold mode release key signal for holding the numerical value of the wavelength solution of light so as not to change. And the controller controls to hold the numerical value of the wavelength of light currently displayed when the hold mode key signal of the hold button is generated so as not to change.

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