KR20030087804A - Equipment and method for eating view port of semiconductor ashing device therefor - Google Patents

Abstract

PURPOSE: A strip failure detecting apparatus of semiconductor ashing equipment and a method thereof are provided to be capable of preventing process error without influencing other apparatuses by generating an interlock signal when detecting the abnormality from a setting voltage. CONSTITUTION: A strip failure detecting apparatus of semiconductor ashing equipment is provided with a strip chamber(10) for generating plasma when carrying out an ashing process, an EPD(End Point Detection) cable(14) connected to the strip chamber for transmitting the wavelength of plasma, and an EPD controller(16). At this time, the EPD controller is used for transforming the wavelength of plasma into a voltage, and generating an interlock signal when detecting abnormality after comparing a real EPD voltage with a setting EPD voltage.

Description

Strip defect detection device and method thereof for semiconductor ashing facility {EQUIPMENT AND METHOD FOR EATING VIEW PORT OF SEMICONDUCTOR ASHING DEVICE THEREFOR}

The present invention relates to an apparatus and a method for detecting a strip failure of a semiconductor ashing device. In particular, an endpoint is detected within a time period set by an EPD graph when stripping a polymer and a photoresist generated after the etching process of a metal line in a semiconductor ashing device. In addition, the present invention relates to an apparatus and a method for generating an interlock signal when the terminal voltage is higher than the set voltage when detecting the endpoint.

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. The layers are 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 a 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 expected 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 the plasma emission intensity at a selected wavelength and displays the 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's processing is completed. 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 et al., Which is incorporated herein by reference, and 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.

In such an etching process, impurities such as a polymer are formed on the wafer as the carbon (C) component of the photoresist pattern and the reaction gas are chemically reacted as the process proceeds. Accordingly, an ashing process for removing impurities such as a photoresist pattern and a polymer formed on the wafer is performed. The ashing chamber is composed of a gas distribution plate (GAS DISTRIBUTION PLATE), a plasma tube, a chuck, and a heating lamp installed in the upper portion of the ashing chamber. The ashing process is performed to remove the photoresist by forming an RF plasma.

However, when the ashing process is aging and the life time of the equipment is not completely removed, not only the defect is generated but also adversely affect other equipment.

Therefore, in the past, a strip error was detected as a strip error only when the EPD was not detected within the set time, so that an interlock was generated. Since there is a problem that the wafer defects occur.

Accordingly, an object of the present invention is to detect the end point of the process that is being ashed when removing the photoresist in the ashing ratio for semiconductor manufacturing to solve the above problems, and then to detect the overstrip failure when the set voltage abnormality is detected An object of the present invention is to provide an overstrip failure detection device for ashing equipment and a method thereof.

Another object of the present invention is to detect an overstrip defect of a semiconductor ashing facility that generates an interlock when the voltage value at the end of the endpoint is checked by detecting the endpoint when the photoresist is removed from the semiconductor ashing facility. And it provides a method.

1 is a block diagram of an apparatus for detecting a wavelength of a plasma of a general semiconductor ashing facility

2 is a voltage waveform diagram corresponding to a plasma wavelength according to an embodiment of the present invention;

Explanation of symbols on the main parts of the drawings

10: strip chamber 12: viewport quartz

14: EPD Cable 16: EPD Controller

18: Chuck 20: Wafer

22 substrate 24 photoresist

26: halogen lamp 28: quartz window

30: optoelectronic filter 32: optical amplifier

34: EPD Board

An apparatus for detecting a strip failure of a semiconductor ashing apparatus of the present invention for achieving the above object includes a strip chamber for forming a plasma during an ashing process, an EPD cable connected to the strip chamber for transmitting a wavelength of the plasma, and the EPD cable. It converts the wavelength of the plasma transmitted through the conversion into a voltage, and detects the voltage at the end point of the EPD, characterized in that it is configured as an EPD controller for generating an interlock signal when it is higher than the set voltage.

Strip defect detection method of the ashing equipment for semiconductor manufacturing of the present invention for achieving the above object, the process of the ashing process for removing the polymer and photoresist formed on the wafer placed on the strip chamber and the ashing process in progress And converting the plasma wavelength transmitted through the cable into a voltage, and generating an interlock signal when the converted voltage is higher than the voltage at the end point of the endpoint.

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.

1 is a block diagram of an apparatus for detecting a wavelength of a plasma of a semiconductor ashing facility according to an embodiment of the present invention.

A strip chamber 10 for forming a plasma during an ashing process, a VIEW PORT QUARTZ 12 for transmitting a wavelength of the plasma formed from the strip chamber 10, and a plasma connected to the view port quartz 12 EPD cable 14 for transmitting the wavelength of the light, and the wavelength of the plasma transmitted through the EPD cable 14 is read to calculate the correct strip time to check the voltage value at the end of the EPD when the voltage is higher than the set voltage. It is composed of an EPD controller 16 for generating an interlock signal (Interlock). The EPD controller 16 monitors the process parameters as described below to analyze the voltage according to the plasma wavelength to accurately determine the process endpoint.

The strip chamber 10 includes a chuck 18, a wafer 20 mounted on the chuck 18, a substrate 22 formed on the wafer, and a photoresist applied on the substrate 22. 24, a quartz window 28 provided below the chuck 18 and having a transparent window, and a halogen lamp 26 provided below the quartz window 28 are provided.

The EPD controller 16 connects an EPD cable 14 to partially filter the plasma wavelength transmitted through the EPD cable 13, and a light of the light through the optoelectronic filter 30. The optical amplifier 32 converts the intensity into the magnitude of the voltage, and receives the converted voltage from the optical amplifier 32, checks the voltage at the time when the endpoint is detected, and generates and outputs an interlock signal when the voltage is higher than the set voltage. It is composed of an EPD board (34).

Referring to Figure 2 described above will be described in detail the operation of the preferred embodiment of the present invention.

When the gas chamber (H2O + O2 + N2) and microwave power are supplied during the ashing process, the strip chamber 10 forms plasma to etch the photoresist and the polymer wafer on which the film is deposited. When gas (H 2 O + O 2 + N 2) and microwave power are supplied into the strip chamber 10, the following reaction occurs.

* O + n-CH ⇒ CO, CO2, H2O (STRIP REACTION)

* CH a ⇒ CH + LIGHT (CHEMIC-LUMEN-ESSENCE)

* OH a ⇒ OH + LIGHT (CHEMIC-LUMEN-ESSENCE)

* N + O ⇒ NO a ⇒ NO + LIGHT (CHEMIC-LUMEN-ESSENCE)

The wavelength of * CH a is 430 nm and the wavelength of OH a is 380 nm.

At this time, the viewport quartz 12 transmits to detect the wavelength of the plasma formed from the strip chamber 10. The EPD cable 14 transmits the wavelength of the plasma transmitted from the viewport quartz 12 to the EPD controller 16. The EPD controller 16 reads the wavelength of the plasma transmitted through the EPD cable 14 and stores the correct etching time and the voltage value at the end of the EPD, and checks the voltage value at regular intervals during the overstrip. Therefore, if it is higher than the voltage at the end of EPD, it is recognized as a strip failure to generate an interlock. The optoelectronic filter 30 of the EPD controller 16 receives the light transmitted through the EPD cable 14 and performs a partial filtering to apply it to the optical amplifier 32. The optical amplifier 32 converts the intensity of light with respect to the wavelength of CH a or OH a in the strip chamber 10 to a magnitude of the current voltage and outputs the converted voltage. In this case, when the normal endpoint is detected, a waveform as shown in FIG. 2 is output. Therefore, the EPD board 34 receives the voltage waveform and checks whether the EPD is detected. When the EPD is detected, the EPD board 34 compares the voltage of the EPD end point, which is stored in advance, to be higher than the EPD end point voltage as shown in FIG. Interlock signal is generated and sent to the main controller (not shown) to stop the process operation. In FIG. 2, the voltage of 5V is output while the photoresist 24 in the strip chamber 10 is removed. However, when the photoresist is almost removed, the voltage drops to 3V and the voltage drops to 0.5V. Recognize that. At this time, the voltage dropped to 0.5V becomes the voltage at the end of the EPD, and the end of the EPD becomes 0.5V when 80% in the graph dotting of FIG. 2. After that, 0.5V is maintained for 20% and the overstrip should be proceeded. However, if an error rises above the voltage at the end of EPD as shown in FIG.

As described above, the present invention compares the detected voltage after the end of the EPD with the voltage at the end of the EPD when the ashing of the polymer and the photoresist generated during the etching process in the ashing device for semiconductor manufacturing is higher than the voltage at the end of the EPD. By generating an interlock and interrupting the process, there is an advantage that can prevent the process error by not affecting other equipment.

Claims (4)

In the strip failure detection device of the semiconductor ashing equipment, A strip chamber for forming plasma during the ashing process, An EPD cable connected to the strip chamber to transmit the wavelength of the plasma; Reads the wavelength of the plasma transmitted through the EPD cable and converts it into a voltage, checks the voltage at the end of the EPD and compares it with a voltage at the end of the EPD when the voltage is higher than the voltage at the end of the EPD. Strip defect detection device of the semiconductor ashing equipment, characterized in that consisting of EPD controller for generating. The method of claim 1, And a viewport quartz for transmitting the wavelength of the plasma formed from the strip chamber. The method of claim 2, wherein the EPD controller, An optoelectronic filter connecting the EPD cable to partially filter the light transmitted through the EPD cable; An optical amplifier converting the intensity of light transmitted through the optoelectronic filter into a magnitude of voltage; Strip failure detection device of a semiconductor ashing facility comprising an EPD board that receives the converted voltage from the optical amplifier and checks the voltage at the time when the endpoint is detected and generates and outputs an interlock signal when the voltage is higher than the set voltage. . A strip chamber that forms a plasma during the etching process, a viewport quartz that transmits the wavelength of the plasma formed from the strip chamber, and a plasma wavelength transmitted from the viewport quartz through the EPD cable to voltage, and checks the voltage at the end of the EPD. In the strip failure detection method of the ashing equipment for semiconductor manufacturing having an EPD controller for generating an interlock signal when the voltage is higher than the preset EPD end point voltage compared with the preset EPD end point voltage, Performing an ashing process for removing the polymer and the photoresist formed on the wafer placed on the strip chamber; Converting the plasma wavelength transmitted through the EPD cable into a voltage during the ashing process; And detecting the converted voltage to generate an interlock signal when the converted voltage is higher than the voltage at the end point of the endpoint.