Patent Application
20190139796
This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2017-0146181, filed on Nov. 3, 2017, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
The inventive concepts relate to a monitoring apparatus for detecting a defect of a process condition during a semiconductor manufacturing process, and an apparatus for manufacturing a semiconductor device including the monitoring apparatus.
A semiconductor device is manufactured through a semiconductor manufacturing process including numerous unit processes such as a thin film process, a photolithography process, an etching process, and/or a diffusion process. Recently, as an influence of a change of a small process parameter on quality of a semiconductor product increases due to refinement of a circuit linewidth, etc., the importance of detecting process abnormality of a semiconductor manufacturing process at an early stage, gradually increases. In order to detect process abnormality of a semiconductor manufacturing process, a wafer can be tested after a unit process is performed, or one or more process parameters such as temperature, pressure, and/or plasma density may be monitored by using various sensors attached on a chamber in which a semiconductor process is performed.
The inventive concepts provide a monitoring apparatus which may monitor whether a flow of a process gas supplied to a process chamber is abnormal, and an apparatus for manufacturing a semiconductor device, the apparatus including the monitoring apparatus.
According to an example embodiment of the inventive concepts, an apparatus for manufacturing a semiconductor device may include a mass flow controller configured to control a flow of a process gas supplied to a process chamber, the mass flow controller configured to adjust an outflow rate of the process gas exiting the mass flow controller in response to a correction signal, the correction signal generated based on a difference between an inflow rate of the process gas flowing into the mass flow controller and a reference flow rate, a sensor configured to measure a chamber pressure inside the process chamber, an exhaust valve configured to adjust an exhaust speed of an exhaust gas exhausted from the process chamber, and a monitoring apparatus configured to detect a defect of the mass flow controller based on the correction signal, the chamber pressure, and the exhaust speed of the exhaust valve.
According to an example embodiment of the inventive concepts, an apparatus for manufacturing a semiconductor device may include a process chamber providing a process space for processing a substrate, a mass flow controller configured to control a flow rate of a process gas supplied to the process chamber, a sensor configured to measure a chamber pressure of the process chamber, an exhaust valve configured to adjust an exhaust speed of an exhaust gas exhausted from the process chamber, and a monitoring apparatus configured to detect the flow rate of the process gas supplied to the process chamber based on the chamber pressure and the exhaust speed of the exhaust gas.
According to an example embodiment of the inventive concepts, a monitoring apparatus for detecting a defect of a mass flow controller controlling a flow of a process gas supplied to a process chamber is configured to generate a correction signal based on a difference between an inflow rate of the process gas flowing to the mass flow controller and a reference flow rate, and detect a defect of the mass flow controller based on the correction signal, environment information inside the process chamber, and an exhaust speed of an exhaust gas exhausted from the process chamber.
Example embodiments of the inventive concepts will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:
Hereinafter, the inventive concepts will be described in detail by explaining some example embodiments of the inventive concepts with reference to the attached drawings. Like reference numerals in the drawings denote like elements.
Referring to
The process chamber 10 may provide a process space for processing a substrate W, and perform a semiconductor manufacturing process, for example, a deposition process, an etching process, a diffusion process, a dry process, and a washing process. The process chamber 10 may include a substrate supporter 111 for supporting the substrate W, a gas introduction port 113 formed in a chamber wall, and a gas exhaust port 115 formed in the chamber wall.
The gas supplier 20 may supply a process gas desired for a semiconductor manufacturing process, the process gas being for processing the substrate W. The gas supplier 20 may adjust a kind of the process gas and/or a flow of the process gas supplied as the process gas according to a desired (or alternatively, preset) process recipe.
The gas supplier 20 may include a gas supply source 201 accommodating the process gas, and a mass flow controller 200 controlling a flow of the process gas supplied to the process chamber 10. The mass flow controller 200 may be provided on a gas supply line connecting the gas supply source 201 to the gas introduction port 113 of the process chamber 10. The mass flow controller 200 may control a flow of the process gas such that a reference (or alternatively, preset) flow rate of the process gas is supplied to the process chamber 10.
In the case where a flow of the process gas different from the reference (or alternatively, preset) flow rate is introduced to the mass flow controller 200, the mass flow controller 200 may adjust a flow of the process gas such that an outflow rate Qout of the process gas flowing from the mass flow controller 200 is equal to the reference (or alternatively, preset) flow rate.
The mass flow controller 200 may include a flow sensor 210, a valve unit 220, and a controller 230.
The flow sensor 210 may measure an inflow rate Qin of the process gas introduced to the mass flow controller 200. For example, the flow sensor 210 may include a mass flow meter. The flow sensor 210 may generate a signal Sin corresponding to an inflow rate Qin introduced to the mass flow controller 200.
The controller 230 may receive a set signal Sset corresponding to a reference (or alternatively, preset) signal and a signal Sin corresponding to the inflow rate Qin transmitted from the flow sensor 210, and generate a correction signal S1 based on the set signal Sset and the signal Sin corresponding to the inflow rate Qin. The correction signal S1 is a signal applied to the valve unit 220 and may be used for driving the valve unit 220 such that an outflow rate Qout flowing from the mass flow controller 200 is equal to the reference (or alternatively, preset) flow rate. The correction signal S1 may have a voltage value or a current value corresponding to a difference between the reference (or alternatively, preset) signal Sset and the signal Sin corresponding to the inflow rate Qin. The controller 230 may transmit the correction signal S1 to the valve unit 220 and the monitoring apparatus 50.
The valve unit 220 may be arranged on a channel prepared inside the mass flow controller 200, and may adjust the outflow rate Qout of the process gas flowing from or exiting the mass flow controller 200. The valve unit 220 is driven in response to the correction signal S1 applied from the controller 230, and may adjust an opening degree of the channel inside the mass flow controller 200 such that the outflow rate Qout is equal to the reference (or alternatively, preset) flow rate.
The sensor unit 30 may be installed to the process chamber 10 and may detect an environment inside the process chamber 10. In an example embodiment, the sensor unit 30 may include a pressure sensor measuring pressure of the process chamber 10 and a temperature sensor measuring temperature inside the process chamber 10. The sensor unit 30 may transmit a signal S2 corresponding to measured environment information inside the process chamber 10 to the monitoring apparatus 50 in real-time.
The exhaust unit 40 may exhaust a gas inside the process chamber 10 through the gas exhaust port 115 of the process chamber 10. The process gas or by-product of a reaction inside the process chamber 10 may be exhausted from the process chamber 10 by the exhaust unit 40. The exhaust unit 40 may adjust pressure of the process chamber 10 by adjusting a flow of an exhaust gas exhausted from the process chamber 10.
The exhaust unit 40 may include a vacuum pump 401 and an exhaust valve 400, and adjust an exhaust speed of the exhaust gas exhausted from the process chamber 10. The exhaust valve 400 may be installed on a gas exhaust line connecting the vacuum pump 401 to the gas exhaust port 115 of the process chamber 10. The exhaust valve 400 may adjust the pressure inside the process chamber 10 by adjusting the exhaust speed. The exhaust valve 400 may transmit a signal S3 corresponding to the exhaust speed to the monitoring apparatus 50 in real-time.
The monitoring apparatus 50 may detect a flow of the process gas supplied to the process chamber 10. In an example embodiment, the monitoring apparatus 50 may use pressure inside the process chamber 10 and an exhaust speed of the exhaust gas exhausted through the exhaust valve 400 to detect a flow of the process gas. The monitoring apparatus 50 may monitor whether the process gas is being supplied to the process chamber 10 at a flow equal to the reference (or alternatively, preset) flow rate.
For example, a flow of the process gas supplied to the process chamber 10 may have a relation shown in Equation (1) below with the pressure of the process chamber 10 and the exhaust speed of the exhaust gas exhausted through the exhaust valve 400.
Q∝a<P·S (1)
where Q is an outflow rate Qout of the process gas flowing from or exiting the mass flow controller 200 and means an actual flow of the process gas supplied to the process chamber 10, P is the pressure inside the process chamber 10 measured by the sensor unit 30, and S is the exhaust speed of the exhaust gas exhausted through the exhaust valve 400.
As illustrated in Equation 1, the actual flow of the process gas supplied to the process chamber 10 may be proportional to the pressure inside the process chamber 10 and the exhaust speed. That is, when the pressure inside the process chamber 10 is constant, the exhaust speed changes depending on the actual flow of the process gas supplied to the process chamber 10. In other words, in the case where the pressure inside the process chamber 10 is constant, when the exhaust speed is raised, the actual flow of the process gas supplied to the process chamber 10 increases. On the contrary, when the exhaust speed is reduced, the actual flow of the process gas supplied to the process chamber 10 is reduced.
Also, as illustrated in Equation 1, in the case where the exhaust speed is constant, when the pressure inside the process chamber 10 increases, the actual flow of the process gas supplied to the process chamber 10 increases. On the contrary, when the pressure inside the process chamber 10 is reduced, the actual flow of the process gas supplied to the process chamber 10 is reduced.
Therefore, a change of the actual flow of the process gas supplied to the process chamber 10 may be known by monitoring the pressure inside the process chamber 10 and the exhaust speed of the exhaust gas exhausted through the exhaust valve 400.
Furthermore, the monitoring apparatus 50 may detect whether the mass flow controller 200 is abnormal. The monitoring apparatus 50 may determine whether a defect occurs in the mass flow controller 200 by analyzing the correction signal S1, the signal S2 corresponding to environment information inside the process chamber 10 measured by the sensor unit 30, and the signal S3 corresponding to the exhaust speed of the exhaust gas exhausted through the exhaust valve 400.
For example, even though a change of a flow of the process gas supplied to the process chamber 10 is determined through monitoring of the environment information inside the process chamber 10 and the exhaust speed of the exhaust gas exhausted through the exhaust valve 400, if an actual flow of the process gas supplied to the process chamber 10 is not controlled by the mass flow controller 200 such that the actual flow of the process gas is equal to a reference (or alternatively, preset) flow rate, it may be determined that a defect has occurred in the mass flow controller 200.
Furthermore, when a defect has occurred in the mass flow controller 200, the monitoring apparatus 50 may detect a cause of the defect having occurred in the mass flow controller 200, that is, a defective portion of the mass flow controller 200, and detect a time at which the defect has occurred in the mass flow controller 200 by analyzing the correction signal S1, the signal S2 corresponding to environment information inside the process chamber 10 measured by the sensor unit 30, and the signal S3 corresponding to the exhaust speed of the exhaust gas exhausted through the exhaust valve 400. A method of detecting a cause of the defect having occurred in the mass flow controller 200 is described in more detail with reference to
In an example embodiment, the monitoring apparatus 50 may include a receiver 510 and a determining unit 520.
The receiver 510 may include a first receiver 511 receiving the correction signal S1 transmitted from the mass flow controller 200, a second receiver 513 receiving the signal S2 corresponding to environment information inside the process chamber 10 transmitted from the sensor unit 30, and a third receiver 515 receiving a signal S3 corresponding to the exhaust speed of the exhaust gas exhausted through the exhaust valve 400. Though not shown in the drawings, the monitoring apparatus 50 may have a database for storing signals received in the receiver 510.
The determining unit 520 may include an algorithm for processing signals received in the receiver 510, and determine whether the mass flow controller 200 is abnormal based on the signals received in the receiver 510. Also, in the case where a defect of the mass flow controller 200 is detected, the determining unit 520 may detect a cause of the defect of the mass flow controller 200. For example, the determining unit 520 may be configured to detect at least one of a defect of the flow sensor 210 or a defect of the valve unit 220.
In an example embodiment, the monitoring apparatus 50 may include a general personal computer (PC), a workstation, and a supercomputer. An analysis program for analyzing the signals may be installed in the monitoring apparatus 50.
In order to detect whether a flow of the process gas supplied to the process chamber 10 is abnormal, a flow of the process gas supplied to the process chamber 10 may be monitored by using a signal obtained from the mass flow controller 200. For example, a flow of the process gas supplied to the process chamber 10 is monitored by using the correction signal S1 for correcting a difference between a flow of the process gas measured by the flow sensor 210 of the mass flow controller 200, and a reference (or alternatively, preset) flow rate. However, in the case where a defect occurs in the mass flow controller 200, a problem that a flow of the process gas different from the reference (or alternatively, preset) flow rate is supplied to the process chamber 10 may not be detected by monitoring only the correction signal S1. For example, even when an actual flow of the process gas supplied to the process chamber 10 is different from the reference (or alternatively, preset) flow rate, in the case where a defect occurs in the flow sensor 210, an erroneous correction signal S1 representing a flow of the process gas equal to the reference (or alternatively, preset) flow rate being supplied to the process chamber 10 may be generated. Also, in the case where a defect occurs in the valve unit 220, even when a correction signal S1 suitable for correcting a flow of the process gas with the reference (or alternatively, preset) flow rate occurs, a flow of the process gas different from the reference (or alternatively, preset) flow rate may flow from the mass flow controller 200 due to a malfunction of the valve unit 220. In this case, because a flow of the process gas different from the reference (or alternatively, preset) flow rate is supplied to the process chamber 10, yield and quality of semiconductor products may be reduced.
The apparatus 1 for manufacturing a semiconductor device may be implement as a virtual metrology (VM) monitoring system which is configured to detect whether the mass flow controller 200 is abnormal by using the correction signal S1, the environment information inside the process chamber 10 measured by the sensor unit 30, and the exhaust speed of the exhaust gas exhausted through the exhaust valve 400 as parameters. The apparatus 1 for manufacturing a semiconductor device may detect a defect of the mass flow controller 200 by analyzing the environment information inside the process chamber 10 and the exhaust speed of the exhaust gas exhausted through the exhaust valve 400 together with the correction signal S1 for adjusting a flow of the mass flow controller 200. Also, according to the inventive concepts, because whether the mass flow controller 200 is abnormal may be monitored in real-time, a defect of the mass flow controller 200 may be detected at an early stage.
Referring to
In an example embodiment, the controller 230 may include a first signal converter 231, a processor 232, a transceiver 233, a second signal converter 234, and a driving circuit 235.
The first signal converter 231 may convert an analog signal corresponding to a flow of the process gas detected from the flow sensor 210 to a digital signal and output the same to the processor 232, and the transceiver 233 may receive a reference (or alternatively, preset) signal Sset (see
The valve unit 220 may adjust an outflow rate Qout (see
Referring to
In an example embodiment, the exhaust valve 400a may include a flange 410 providing a channel through which an exhaust gas may flow, and a rotation body 420 may be rotatably installed on the flange 410. The rotation body 420 may be configured to rotate around a rotational axis 430. The exhaust speed may be adjusted depending on the open angle θ by which the rotation body 420 rotates around the rotational axis 430 from a state in which the rotation body 420 closes the channel provided by the flange 410.
The exhaust valve 400a may transmit the open angle θ to the monitoring apparatus 50 (See
Referring to
For example, the monitoring apparatus 50a may include a receiver 510a, a determining unit 520, and a correction signal generator 530.
The receiver 510a may include a first sub-receiver 511a receiving the signal Sin corresponding to the inflow rate Qin transmitted from the controller 230a of the mass flow controller 200a, and a second sub-receiver 511b receiving the reference (or alternatively, preset) signal Sset transmitted from outside. The signal Sin corresponding to the inflow rate Qin and the reference (or alternatively, preset) signal Sset received in the first sub-receiver 511a and the second sub-receiver 511b, respectively, are transmitted to the correction signal generator 530, and the correction signal generator 530 may generate the correction signal S1 based on the signal Sin corresponding to the inflow rate Qin and the reference (or alternatively, preset) signal Sset.
The correction signal generator 530 may transmit the generated correction signal S1 to the determining unit 520 and the mass flow controller 200a. The mass flow controller 200a may adjust driving of the valve unit 220 such that the outflow rate Qout flowing from the mass flow controller 200a is equal to the reference (or alternatively, preset) flow rate based on the correction signal S1 transmitted from the monitoring apparatus 50a.
Referring to
After the substrate W is arranged inside the process chamber 10, a semiconductor process, for example, a deposition process, an etching process, a diffusion process, a dry process, and a washing process may be performed on the substrate W (S120). To perform a semiconductor manufacturing process on the substrate W, a flow of the process gas supplied to the process chamber 10 may be controlled by using the mass flow controller 200. The mass flow controller 200 may supply a reference (or alternatively, preset) flow rate of the process gas to the process chamber 10 according to a process recipe.
While the semiconductor manufacturing process is performed, the correction signal S1, the environment information inside the process chamber 10, and the exhaust speed of the exhaust gas exhausted through the exhaust valve 400 are monitored (S130). The correction signal S1 is a signal corresponding to a difference between an inflow rate Qin of the process gas introduced to the mass flow controller 200 and a reference (or alternatively, preset) flow rate. The correction signal S1 may be generated by the mass flow controller 200 and transmitted to the monitoring apparatus 50. The sensor unit 30 may measure the environment information inside the process chamber 10, for example, temperature and/or pressure of the process chamber 10, and transmit a signal corresponding to the measured value to the monitoring apparatus 50 in real-time. Also, the exhaust valve 400 may transmit information which may represent an exhaust speed, for example, information regarding an open angle 9 (see
Whether the mass flow controller 200 is abnormal is determined based on the correction signal S1, the environment information of the process chamber 10, and the exhaust speed of the exhaust gas exhausted through the exhaust valve 400 (S140). Whether the mass flow controller 200 is abnormal may be determined by the monitoring apparatus 50, and detected in real-time while the semiconductor manufacturing process is performed.
In the case where a defect of the mass flow controller 200 is not detected (NO in S140), monitoring for detecting a defect of the mass flow controller 200 is ended, and the semiconductor manufacturing process for the substrate W is completed.
Meanwhile, in the case where a defect of the mass flow controller 200 is detected (YES in S140), the semiconductor manufacturing process for the substrate W is stopped, and a cause of the defect of the mass flow controller 200 is analyzed (S150). In an example embodiment, the monitoring apparatus 50 may detect a defect of the flow sensor 210 of the mass flow controller 200 and/or a defect of the valve unit 220 of the mass flow controller 200 by monitoring the correction signal S1, the pressure inside the process chamber 10, and a change in the exhaust speed of the exhaust gas exhausted through the exhaust valve 400 over time. The method of detecting a cause of a defect of the mass flow controller 200 is described in more detail with reference to
After a cause of the defect of the mass flow controller 200 is detected, the detected defect of the mass flow controller 200 may be removed (S160). For example, maintenance may be performed on the mass flow controller 200, the mass flow controller 200 may be replaced, or an appropriate feedback operation may be performed such that a flow of the process gas supplied to the process chamber 10 is calibrated to be equal to a reference (or alternatively, preset) flow rate. When a defect of the mass flow controller 200 is removed, the semiconductor manufacturing process for the substrate W may be performed and monitoring of the mass flow controller 200 may be performed.
Referring to
As described above, because a flow of the process gas supplied to the process chamber 10 is proportional to the pressure inside the process chamber 10 and the exhaust speed of the exhaust gas exhausted through the exhaust valve 400, the flow of the process gas supplied to the process chamber 10 becomes less than a reference (or alternatively, preset) flow rate Qset after the first time point T1 as illustrated in
As illustrated in
Also, in the graph illustrated in
As illustrated in
Therefore, the apparatus 1 for manufacturing the semiconductor device according to example embodiments may detect a defective element in the mass flow controller 200, and/or accurately detect a time point at which the defect has occurred.
While the inventive concepts have been particularly shown and described with reference to some example embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the inventive concepts as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2017-0146181 | Nov 2017 | KR | national |
