Patent Application
20080009977
The present invention relates generally to the field of chemical delivery systems and more specifically to chemical delivery systems used in semiconductor processing equipment. The present invention relates to apparatuses and methods used to monitor these chemical delivery systems.
Advanced microelectronic devices are being manufactured with ever increasing device density and complexity. The device dimensions are decreasing in both the lateral and vertical directions. Smaller device elements allow for increasingly complex, faster, and more powerful devices. The multitude of layers and materials used in the construction of these advanced devices are being deposited by a number of well known techniques comprising low pressure thermal chemical vapor deposition (LPCVD), plasma enhanced chemical vapor deposition (PECVD), atmospheric pressure chemical vapor deposition (APCVD), physical vapor deposition (PVD), thermal conversion of the substrate, and the like.
Additionally, other well known techniques comprising etch, chemical mechanical polishing (CMP), ion implantation, electroplating, photoresist processing, and the like have also seen rapid development. Each of these techniques involves the controlled delivery of various chemical species in either a liquid or gaseous state to the substrate to facilitate the practice of the specific process method. Examples of suitable substrates comprise silicon wafers, gallium arsenide wafers, glass substrates as used in the manufacture of flat panel displays, “thin film head” substrates as used to manufacture memory disk drives for computers, substrates used in the manufacture of photonic devices, substrates used in the manufacture of micro-electro-mechanical systems (MEMS) devices, polymeric substrates as might be used for organic-based devices, and the like.
The high device density and small device dimensions are driving increasingly stringent requirements and specifications for the control, precision, repeatability, and reliability of chemical delivery subsystems used in semiconductor processing equipment. Small variations in the control, precision, and repeatability of the delivery of the various chemical species may have a profound effect on the quality, repeatability, and success of the process method. The repeatability and stability of the process method may be degraded if the component parts of the chemical delivery system degrade slowly over time. This may lead to degradation in the performance, yield, and quality of the device being manufactured. Long term, systematic changes in the performance of the component parts of the chemical delivery systems are difficult to identify, troubleshoot, and correct since the changes over time may be very small. Consequently, a large number of substrates may be processed before a significant error is identified. This may lead to some of these substrates being scrapped leading to an economic loss to the customer. Once a change in the performance of the chemical delivery system has been identified, it may be difficult to determine which component parts are responsible for the change. This may lead to long troubleshooting, maintenance, and non-productive times for the equipment.
Further, the processing apparatus may contain several, e.g., 5-10 systems, each with multiple components, making it difficult and laborious to systematically check the performance characteristics of each component of each system.
Therefore, a need exists in the art for apparatus and method for the readily monitoring, analysis, troubleshooting, and correction of components in the systems, including a chemical-delivery system, of a processing apparatus.
In one aspect, the invention includes a processing apparatus intended for operation under specified processing conditions. The apparatus includes (a) a chemical-delivery system having a plurality of components that operate to deliver a defined fluid or fluids in the system, where the performance specifications of the components required for the intended operation of the apparatus are known or identified, (b) monitoring devices operatively connected to the system components for transmitting signals related to the performance of the components, (c) an interface operatively connected to the monitoring devices for receiving such signals, and (d) an electronic computer operatively connected to the interface and including (d1) a storage device for storing information about the performance characteristics of the components known or identified in (a), and (d2) a display device for displaying system performance information.
A machine readable storage medium capable of operation on the computer performs the steps of (i) calculating from information related to the performance-based signals received from the interface, a Health Index of the system based on an aggregate component performance, (ii) displaying the Health Index of the System, and (iii) initiating a trouble-shooting routine on components of the chemical-delivery system if the Health Index of the system is below a preselected threshold value relative to a signature Health Index of the system based on an aggregate component performance calculated from the performance characteristics known or identified in (a).
The signature Health Index provides a desired baseline performance metric for the system, against which changes in the system over time can be measured or calibrated. Thus, as long as the measured Health Index of the system is within a selected range of the signature, e.g., 96% of the signature HI, the system is judged to be functioning at a desired or optimal level consistent with the specified operation of the system, recognizing that different apparatus operations will require different performance capabilities.
The components of the chemical-delivery system may include a plurality of valved fluid controllers, and the performance characteristics of the valved components may be related to the response time and/or degree of opening of a valve. The chemical delivery system may be a gas panel for controlling and mixing gases from a plurality of sources.
The computer may calculate the Health Index as a linear combination of weighted component performance values.
The apparatus may include a plurality of such multi-component processing systems, and for each such system, monitoring devices for monitoring the system components, and the computer and machine-readable code may operate to calculate a Health Index for each such system.
In another aspect, the invention includes a method for identifying a problem component in a multi-system microfabrication apparatus intended for operation under specified processing conditions, where each system is composed of multiple components and the performance specifications of the components in each system required for the intended operation of the apparatus are known or identified. The method includes the steps of monitoring the performance of each component of the systems, using the monitored performance of each component to calculate, for each system, a Health Index of the system based on an aggregate component performance, and initiating a trouble-shooting routine on components of a system if the Health Index of that system is below a preselected threshold value relative to a signature Health Index of that system based on an aggregate component performance calculated from the performance characteristics known or identified, thus to identify one or more problem components.
One of the systems may be a chemical-delivery system, and the components of the system may include a plurality of valved fluid controllers.
Also disclosed is a system for monitoring chemical delivery system performance. The system includes one or more components within a chemical delivery system connected to a network; a computer connected to the network capable of receiving and storing component data transmitted across the network; a user interface for interacting with the computer; a computer readable medium containing procedures for acting upon the component data; and output devices for displaying the results of the procedure action upon the component data.
These and other objects and features of the invention will become more fully apparent when the following detailed description of the invention is read in conjunction with the accompanying drawings.
After considering the following description, those skilled in the art will clearly realize that the teachings of the invention can be readily utilized in monitoring the performance of chemical delivery systems. As an example, chemical delivery systems used in semiconductor processing equipment will be used, but this is not intended to limit the scope of the present teaching in any way. Examples of semiconductor processing equipment comprise deposition systems, etch systems, CMP systems, ion implantation systems, electroplating systems, photoresist processing systems, and the like. In the following examples, a generic deposition system will be discussed, but this is not intended to limit the scope of the present teaching in any way.
A plurality of substrates is typically contained within a holder and is placed in the substrate handling subassembly, 101. Silicon wafers for use as substrates for the manufacture of semiconductor devices will be used as examples. However, the substrates may comprise compound semiconductors, flat panel displays, substrates for MEMS (micro electronic mechanical systems) devices, substrates for photonic devices, substrates for thin film head manufacture, polymers, ceramics, and the like. This exemplary use of silicon wafers does not limit the teaching of the present invention in any way. Typically, the wafers may be transferred from the cassette into one of the process chambers, 104, by transfer robot, 103, passing through transfer hub, 102. The transfer may occur at atmospheric pressure or may occur at a reduced pressure. The most common practice makes the transfer at a reduced pressure. In the case of transfer at a reduced pressure, there may be an intermediate loadlock chamber (not shown) between the substrate handling subassembly and the transfer hub or the substrate handling subassembly may have the ability to be evacuated to a reduced pressure. The specific process method associated with that process chamber is then practiced and the wafer may be returned to the cassette or may be transferred to another process chamber for the practice of additional process methods. Finally, the wafer is returned to the cassette and the cassette may be sent to the next processing system for additional steps in the manufacture of the devices. The operation of the apparatus is generally under the control of a computer 106. In the apparatus of the present invention, and as described below, computer 106 also functions to process performance-related signals from system components in the apparatus, for monitoring components and identifying problem components, in accordance with the invention.
At least some of the components in the chemical-delivery system have associated therewith, a monitoring device, such as devices 210, 212, 214, 216, and 218, associated with components 201, 202, 203, 204, and 203, respectively, for monitoring the performance characteristics of the associated components, by generating signals related to the performance of the associated components. Such monitoring devices are well known in the gas panel field, and typically are incorporated into the component as an integral component, that is, supplied as an integral part of a commercially available component. The devices are designed to measure, for example response times and extent of openings of valve elements in valve elements of the components, in response to a given voltage input on the component, or measure temperature or pressure performance values associated with component operation. Associated with each monitoring device is a line connection, such as lines 220, 222, 224, 226, and 228, associated with devices 210, 212, 214, 216, and 218, respectively, for carrying signals from the monitoring devices to an interface 230 connected to computer 106, and which functions to convert the device signals to digital signals suitable for computer input.
In some embodiments of the present invention, the chemical delivery system may be a gas box. In the context of the present invention, the phrase “gas box” will be understood to convey its typical meaning in the art and may comprise an enclosure wherein many of the components used to control, measure, and flow the various gases used in the practice of the process method are housed. The gas box may also comprise vaporizer components wherein an input chemical is in a liquid form and is converted to a gaseous form before being conveyed to the process chamber. The phrase “gas box” is well known and will be understood by those skilled in the art.
The gas box may comprise a number of gas lines as illustrated in
In some embodiments of the present invention, a software resource may be used for monitoring, analysis, and diagnosis of the performance of the entire gas box. The inventors will refer to this resource as a “Health Index Monitoring and Analysis (HIMA)” system. The HIMA system may reside on the system control computer and/or may reside on the engineer's remote computer if the system is connected to a suitable network. Examples of suitable networks comprise the Internet, a Local Area Network (LAN), a Wide Area Network (WAN), a wireless network, cellular networks (e.g. GSM, GPRS, etc.), combinations thereof, and the like.
Typically, the HIMA system may comprise a graphical user interface (GUI) used to manage the human to machine interface and to display information comprising status, alerts, errors, setpoints for various components, actual flows for various gases, valve settings, offset parameters, communications information, and the like. An exemplary screen shot of one possible GUI display is illustrated in
In some embodiments of the present invention, the HIMA system is installed on the system computer and/or the engineer's remote computer. Typically, the communications network within the processing equipment exists and the various components within the gas box are connected to the network. The HIMA system has been designed to be hardware and component supplier agnostic in that it will work with all hardware and components that can communicate across one of the standard communication interface protocols. The user may select the specific communication interface protocol used by the specific processing equipment under consideration from a drop down menu on the GUI. The HIMA system comprises a “SCAN NETWORK” function that may scan the network, locate the components within the gas box, query their communications addresses, and populate the database fields. The “SCAN NETWORK” function may be activated at initial system start-up or may be activated at any other time such as after a component change or maintenance activity. The user may display the details of any component by selecting the channel number corresponding to the communications address of that component. If a component is selected during the practice of the process method, real-time data indicating the transient characteristics of the device may be displayed. The transient characteristics may be displayed numerically or graphically. Again, this feature may be activated from the GUI. These exemplary steps, 500-509, are illustrated in
Typically, the HIMA system may be used to detect abrupt component failures. The user may set limits around important parameters and set flags for alert levels and error levels. The user may select a number of responses within the HIMA system if an alert or error condition is reached. Examples of responses may comprise sending an error signal to the system control computer, sending an email to the user, sending a page to the user, send a voice or text message to the user's cellular phone, displaying warning messages on the GUI, and the like.
In some embodiments of the present invention, the HIMA system may be used to detect errors and failure modes within the components that may be due to long term drift, loss of calibration, component degradation, and the like. The HIMA system may store and analyze data over long periods of time to detect slow, systematic failures or degradation in the components. The HIMA system may alert the user to components whose performance is degrading.
In some embodiments of the present invention, the HIMA system aggregates all of the data and may establish a “health index” (HI) for the components as well as for the entire gas box. The HI comprises at least one value that may be computed from the data received from the gas box components. The Hi for the gas box may be a weighted figure of merit based on all of the components within the gas box. Exemplary input data from each component into the establishment of the HI may comprise Accuracy, Control Time, Settling Time, Overshoot, Undershoot, Inlet Pressure, Gas temperature, Valve Voltage, Valve Current, Supply Voltage, Zero Offset, Leak By (when the setpoint=0), Valve Response Time, Current Sensor Offset, Reference Sensor Offset, Calibration Date, Calibration Due Date, Moisture Analysis Data, Rate-of-Rise Data, and the like. Each data point is given a numerical index if it is within a user defined range of the target value. The established HI for the entire gas box may be reported as a percentage (e.g. 90%) as illustrated in
Typically, the supplier or customer may establish an algorithm to calculate the HI. In one example, the HI may be a linear combination of the weighted averages of the parameters described earlier, as well as others. One example is illustrated below:
HI=a(Accuracy)+b(Control Time)+c(Settling Time)+d(Overshoot)+e(Undershoot)+f(Inlet Pressure)+g(Gas temperature)+h(Valve Voltage)+i(Valve Current)+j(Supply Voltage)+k(Zero Offset)+l(Leak By (when the setpoint=0))
Where the coefficients a-l are values between 0 and 1 and the parameters are expressed as a percentage of their expected (desired or optimal) value. In this way, the HI value may be expressed as a percentage where 100% would represent the optimum health. Typically, the end user or customer may select the coefficients such that those parameters that are of primary importance are emphasized. This algorithm is used for illustrative purposes only and does not limit the present invention in any way. It will be appreciated by those skilled in the art that the algorithm may be tailored by the user to highlight, track, and report those data that are of particular importance for the specific process method being practiced.
Typically, an HI value may be computed for each chemical delivery line within the gas box to track the performance of individual lines and to facilitate the troubleshooting and maintenance of the chemical delivery system. Therefore, another algorithm for calculating the HI for the entire chemical delivery system may comprise some combination of the HI values for each chemical delivery line. Those skilled in the art will appreciate the value of this capability.
Typically, the HIMA system may advantageously exploit the stored data and the HI to aid in the troubleshooting and diagnosis of gas boxes that are performing poorly. The HIMA system may shorten the troubleshooting time by indicating to the service personnel the identity of those systems having suboptimal HI, and within that system, the identity of components that may have sub par performance values. The diagnostics features of the HIMA system may be loaded with routine failures and corrective actions and may be queried by the service personnel during the troubleshooting activity. This may shorten the time for troubleshooting and maintenance, increase the overall equipment uptime, and provide increased economic value to the customer through improved overall equipment efficiency (OEE).
The input interfaces, 603, may comprise a keyboard, 607, and a mouse, 60, selected operating mode in the system, and include, for example, value response time and percent opening in response to given voltage inputs. These “optimal” values are then used to calculate a signature Health Index for the system, and it is against this signature HI that changes in the HI of the system, as the performance of one or more components changes, that the HI of the system is reported; for example, a 70% HI indicates a HI that is 70% of the signature HI determined as above.
The output interface, 604, may comprise a printer, 609. The communications interface, 606, is a network interface that allows the computer system to communicate via a wireless or hardwired network as previously described.
The memory modules, 610, generally comprise different modalities, illustratively semiconductor memory, such as random access memory (RAM), and disk drives as well as others. In various embodiments, the memory modules, 610, store an operating system, 611, collected data, 612, instructions, 613, applications, 614, and procedures, 615.
In various embodiments, the specific software instructions, data structures and data that implement various embodiments of the present invention are typically incorporated in the computer, 601, and are referred to herein as machine-readable storage medium. Generally, an embodiment of the present invention is tangibly embodied in a computer readable medium, for example, the memory and is comprised of instructions, applications, and procedures which, when executed by the processor, causes the computer system to utilize the present invention, for example, the collection, aggregation, and analysis of data, establishing benchmark metrics for performance, comparing performance data to the benchmark metrics, displaying the results of the analyses, and the like. The memory may store the software instructions, data structures, and data for any of the operating system, the data collection application, the data aggregation application, the data analysis procedures, and the like in semiconductor memory, in disk memory, or a combination thereof.
Specifically, the computer readable medium capable of operation on said computer to perform the steps of:
(i) calculating from information related to said performance-based signals received from said interface, a Health Index of the system based on an aggregate component performance,
(ii) displaying the Health Index of the System, and
(iii) initiating a trouble-shooting routine on components of the chemical-delivery system if the Health Index of the system is below a preselected threshold value relative to a signature Health Index of the system based on an aggregate component performance calculated from the performance characteristics known or identified in (a).
As discussed above, step (i) includes receiving input data signals on components in the system, converting each of the signals to a weighted performance metric, e.g., a percent of the desired “signature” performance, and using the aggregate date to construct a Health Index for the System at that point in time.
Step (ii) is simply displaying the Health index for the system on the display monitor. Typically, the display will include the HI for each system in the apparatus, so that the user can readily identify any system that is operating at a sub par level, or the display may include only HI information about those systems that are operating sub par.
Step (iii), initiating a trouble-shooting routine, involves deconvoluting the HI for a given sub par system, to identify one or more components whose sub par performance is responsible for the sub par HI. This can be done readily, for example, by determining the weighted performance characteristic of each component in the system, and identifying those components whose weighted values are most heavily contributing to the sub par HI score.
The operating system may be implemented by any conventional operating system comprising Windows® (Registered trademark of Microsoft Corporation), Unix® (Registered trademark of the Open Group in the United States and other countries), Mac OS® (Registered trademark of Apple Computer, Inc.), Linux® (Registered trademark of Linus Torvalds), as well as others not explicitly listed herein.
In various embodiments, the present invention may be implemented as a method, system, or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term “article of manufacture” (or alternatively, “computer program product”) as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier or media. In addition, the software in which various embodiments are implemented may be accessible through the transmission medium, for example, from a server over the network.
The article of manufacture in which the code is implemented also encompasses transmission media, such as the network transmission line and wireless transmission media. Thus the article of manufacture also comprises the medium in which the code is embedded. Those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the present invention.
The exemplary computer system illustrated in
Referring now to
Continuing to refer to
Although various embodiments which incorporate the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings.
This application claims the benefit of U.S. Provisional application Ser. No. 60/819,836, filed Jul. 10, 2006, which is incorporated in its entirety by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 60819836 | Jul 2006 | US |
