The subject matter disclosed herein relates to thin film production and, in particular, monitoring operation of thin film fabrication systems.
As technology has continued to evolve, use of thin films has become increasingly important. Thin films have been used in a variety of fields ranging from the electronics industry, such as in semiconductors and for computer memories, to pharmaceuticals for thin film drug delivery. As thin film popularity has increased, methods of fabricating thin films have been developed. Examples of these processes include deposition methods, such as atomic layer deposition, and etch methods, such as atomic layer etch.
In exemplary etch and deposition techniques, a substrate is placed in a reaction chamber and a succession of gases are released into the chamber to react with a surface of the substrate. The entire process chamber for these techniques is subjected to quick pressure changes due to rapid valve open/close cycles, which open/close cycles increase the wear of the hardware components and may cause a component to malfunction. Currently, to identify malfunctioning hardware in a varying pressure environment, the completed thin film is analyzed. If the thickness and/or composition of the thin film is not accurate, the hardware is identified as malfunctioning. However, due to time and cost constraints, not every sample can be tested, resulting in malfunctions not being identified immediately. Because of this delay, large numbers of defective samples can be produced, resulting in high costs.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
A method and system for monitoring operation of a reaction chamber for operation malfunctions are described herein. The reaction chamber includes a pressure gauge coupled therewith to collect pressure data within the reaction chamber during operation of the reaction chamber. The pressure data is received in a processor and a plurality of pressure readings are generated from the pressure data, identifying pressure changes within the reaction chamber during operation. The plurality of pressure readings are analyzed to identify an abnormal pressure change and an operating malfunction is determined when the abnormal pressure change is identified.
In one embodiment of the invention, a device for monitoring valve function is described. The device includes a reaction chamber for receiving a substrate and a plurality of gas inlets for introducing a plurality of gases to the reaction chamber. The device also includes a plurality of valves, a valve coupled to each gas inlet to control flow of gas through each gas inlet to the reaction chamber and a high-speed pressure gauge coupled to the reaction chamber to monitor pressure within the reaction chamber. A processor is coupled to the pressure gauge and configured to receive pressure data from the pressure gauge and generate a plurality of pressure readings to identify pressure changes within the reaction chamber due to operation of the plurality of valves. The processor compares the generated pressure readings to a reference pressure reading and analyzes the generated plurality of pressure readings to identify a change in pressure that differs from the reference pressure reading. The processor is further configured to identify which valve was operating during the change in pressure and diagnose the identified valve as a malfunctioning valve.
In another embodiment of the invention, a method for monitoring operation of a reaction chamber for malfunctions is described. The reaction chamber includes a high-speed pressure gauge coupled therewith to collect pressure data within the reaction chamber during operation of the reaction chamber. The method includes receiving, in a processor, the pressure data from the pressure gauge. A plurality of pressure readings is generated from the pressure data, identifying pressure changes within the reaction chamber during operation. The plurality of pressure readings is analyzed to identify an abnormal pressure change and an operating malfunction is determined when the abnormal pressure change is identified.
In another embodiment of the invention, a tangible, non-transitory, computer-readable storage medium including instructions to direct a processor to monitor operation of a reaction chamber for malfunctions is described herein. The reaction chamber includes a high-speed pressure gauge coupled therewith to collect pressure data within the reaction chamber during operation of the reaction chamber. The instructions direct the processor to receive the pressure data from the pressure gauge and generate a plurality of pressure readings from the pressure data identifying pressure changes within the reaction chamber during operation. The instructions further direct the processor to analyze the plurality of pressure readings to identify an abnormal pressure change and determine an operating malfunction when the abnormal pressure change is identified.
This brief description of the invention is intended only to provide a brief overview of subject matter disclosed herein according to one or more illustrative embodiments, and does not serve as a guide to interpreting the claims or to define or limit the scope of the invention, which is defined only by the appended claims. This brief description is provided to introduce an illustrative selection of concepts in a simplified form that are further described below in the detailed description. This brief description is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background.
So that the manner in which the features of the invention can be understood, a detailed description of the invention may be had by reference to certain embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain embodiments of this invention and are therefore not to be considered limiting of its scope, for the scope of the invention encompasses other equally effective embodiments. The drawings are not necessarily to scale, emphasis generally being placed upon illustrating the features of certain embodiments of the invention. Thus, for further understanding of the invention, reference can be made to the following detailed description, read in connection with the drawings in which:
In an embodiment, the reaction chamber 102 is an atomic layer deposition (ALD) chamber. ALD is a coating method in which a coating is deposited onto a flat surface to a specific thickness, to a molecular level, and having a specific stoichiometry. ALD is at least a two part process in which a portion of each molecular layer is deposited in each part.
In this embodiment, a plurality of gas inlets 106, 108, 110 direct the flow of the various gases into the reaction chamber 102 while a pumping system outlet 118 allows the gases to be removed from the reaction chamber 102. While three gas inlets are illustrated here, the number of gas inlets depends on the design of the reaction and the number of gases to be added to the reaction chamber 102. As illustrated here, the gas inlets 106, 108, 110 can be combined into a single inlet before entering the chamber. However, other designs, where the gas inlets 106, 108, 110 remain individual, are also possible. Each gas inlet 106, 108, 110 includes a valve 112, 114, 116 to regulate the flow of gases through the gas inlets 106, 108, 110 into the reaction chamber 102. A mass flow controller (not shown) can be coupled to each gas inlet 106, 108, 110 to control the flow rate of each gas. Opening and closing of the valves 112, 114, 116 occurs quickly and results in sudden large changes in pressure in the reaction chamber 102. Each reactant gas valve is kept open only long enough for a monolayer of the reactant to be deposited on the surface of the substrate. Keeping the valve open longer wastes both time and gas. The amount of time each valve is opened and closed ranges from less than 0.1 seconds to a few seconds or more, depending on the design of the process. Typically, only one valve is open at once and all valves are closed in between each valve being open, but other valve sequences are possible. A pressure monitor P 120 monitors the pressure within the reaction chamber 102 during operation. The pressure monitor P 120 is a high-speed pressure monitor, gathering pressure data from 10 to 1000 or more times per second.
In an exemplary ALD process, an aluminum oxide (Al2O3) coating is deposited on the substrate 104. To deposit this coating, a first valve 112 of a first gas inlet 106 is opened and a first gas including Aluminum, such as trimethylaluminum (TMA) Al(CH3)3 flows into the reaction chamber 102. When the first gas contacts the substrate 104, a monolayer of reactant is deposited on the surface of the substrate 104. When the desired time has been reached, the first valve 112 is closed and the first gas is removed from the reaction chamber 102 via the pumping system outlet 118. In an example, the first valve 112 is open for 0.2 seconds.
A second valve 114 (purge valve) of the second gas inlet 108 is opened, releasing a purge gas through the second gas inlet 108 into the reaction chamber 102. The purge gas is typically a gas that does not react with the other gases and is intended to remove any traces of the first gas that may remain in the reaction chamber 102, preventing the remaining first gas from reacting to the second gas upon release of the second gas into the reaction chamber 102. The second valve 114 is closed and the purge gas is removed from the reaction chamber via the pumping system outlet 118. In an example, the second valve 114 is open for 0.1 seconds.
Following removal of the purge gas, the third valve 116 is opened and a second gas, such as Oxygen gas O2 is released into the chamber 102 via the third gas inlet 110. The Oxygen gas deposits the second half of the coating layer on the substrate surface, resulting in a single molecular layer of aluminum oxide. In an example, the third valve 116 is open for 0.3 seconds. After deposition, the third valve 116 is closed and the third gas is removed from the reaction chamber 102 via the pumping system outlet 118. The purge gas can be introduced to the system before and/or after each of the first gas and the second gas is introduced and removed. The deposition cycle can be repeated until the desired coating thickness is reached, which may require only a few cycles or hundreds or thousands of cycles, depending on the desired thickness.
The quick opening and closing of the valves 112, 114, 116 results in sudden large changes in pressure in the reaction chamber 102. These changes in pressure are monitored by a high-speed pressure monitor P 120 coupled to the reaction chamber 102. The pressure monitor P 120 can collect the pressure data at a high rate. For example, the pressure monitor P 120 can collect pressure data recordings 1000 times per second. The pressure data collected by the pressure monitor 120 can be transmitted to a processor 121. The processor 121 can analyze the pressure data to generate a plurality of pressure readings. In an embodiment, these pressure readings can be in the form of a pressure data waveform. Each pulse in the waveform corresponds to hardware operation, for example, referring to the valves, opening and closing of a valve. The waveform is analyzed to determine the size and shape of each pulse and other characteristics of the waveform. This information is then compared to the characteristics of a waveform recorded during known normal operation to determine if operation of the valve, or any other type of hardware being analyzed, is abnormal.
The frequent opening and closing of the valves causes them to wear quickly. When the valves begin to wear, the valves can malfunction in a variety of ways. Examples of valve malfunctions include the valve failing to open and/or close quickly enough, the valve failing to open and/or close fully, the valve failing to open at all, and a valve opening out of order, among others. By monitoring the pressure in the reaction chamber 102, hardware malfunctions, such as valve malfunctions, can be identified. For example, malfunctions related to gas delivery hardware, such as mass flow controller malfunctions and outward pumping system malfunctions, are identifiable as described herein. Incorrect valve sequencing can also be identified, whether it is due to malfunction or to improper design of the valve sequence controller.
Once the waveform diagram is generated 302 from the pressure data, in block 304, a pressure pulse for each valve operation instance (valve opening and closing) is identified. At block 306, each identified pulse is associated with the respective valve whose operation instance is represented by the pulse. For example, the pulse can be identified with the respective valve by determining which valve was operating when the pressure pulse was recorded.
At block 308, a maximum amplitude Amax-normal of each pulse is identified. The maximum amplitude A is the maximum height reached by the pulse. At block 310, a time to plateau tplateau-normal is identified for each pressure pulse. At block 312, the amplitude Aplateau-normal of each pulse plateau is identified. At block 314, the lowest pressure plateau level Pmin-normal reached after each pulse is identified. At block 316, the information identified in the foregoing blocks is determined to be normal, expected pulse parameters and the information is saved in memory as said normal, expected parameters to which subsequent data will be compared. In another example, the identified pulse parameters are used to determine a range of acceptable values, such as an acceptable threshold value.
At block 506, the size and shape of each pulse is determined. At block 508, the determined size and shape of each pulse is compared to the normal, expected pulse parameters. For example, the determined pulse parameters can be compared to the normal pulse parameters determined as discussed regarding
At block 706, the size and shape of each pulse is determined. The size and shape include the maximum amplitude, the plateau amplitude, the pulse width, etc. At block 708, the determined size and shape of each pulse is compared to the normal, expected pulse parameters. For example, the determined pulse parameters can be compared to the normal pulse parameters determined as discussed regarding
At block 906, the size and shape of each pulse is determined. The size and shape include the maximum amplitude, the plateau amplitude, the pulse width, etc. At block 908, the determined size and shape of each pulse is compared to the normal, expected pulse parameters. For example, the determined pulse parameters can be compared to the normal pulse parameters determined as discussed above regarding
During comparison of these pulse parameters, the maximum amplitude Amax of each pulse is compared to the normal, expected maximum pulse amplitude Amax-normal. At block 910, the maximum pulse amplitudes Amax for pulses 802 and 804 are identified as larger than the normal, expected maximum pulse amplitude Amax-normal. Also during comparison of the pulse parameters, the lowest pressure Pmin following each pulse is identified. At block 912, lack of a low pressure plateau following operation of the purge valve is identified. At block 914, based on the identified larger than normal maximum pulse amplitude of pulses 802 and 804 and the lack of a low pressure plateau following purge valve operation, the purge valve is identified as malfunctioning. In particular, the purge valve is identified as failing to close quickly enough and remaining open during the beginning of operation of valve B.
Based on pressure data gathered from the reaction chamber, at block 1002, a pressure waveform is generated, representing pressure changes within the reaction chamber during operation. At block 1004, a pulse of the waveform is identified. At block 1006, the maximum amplitude of the pulse is identified. At block 1008, the processor 121 (
At block 1012, the time for the pulse to plateau is determined. At block 1014, the processor 121 (
At block 1016, the amplitude of the pulse plateau is determined. At block 1018, the processor 121 (
At block 1020, the amplitude of the lowest pressure plateau following each pressure pulse is determined. At block 1022, the processor determines if the amplitude of the lowest pressure plateau following each pressure pulse falls within the predetermined range. If the lowest pressure plateau following each pressure pulse does not fall within the predetermined range, operation malfunction is determined at block 1010. If the lowest pressure plateau following each pressure pulse does fall within the predetermined range, the method continues at block 1024. Upon identification of an operation malfunction, the processor 121 (
Methods other than those described in
In view of the foregoing, embodiments of the invention provide a method for identifying malfunctioning valves in a reaction chamber. A technical effect is to enable early repair or replacement of the malfunctioning valves and prevent an increase in production of defective thin film samples.
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method, or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.), or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “service,” “circuit,” “circuitry,” “module,” and/or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
Any combination of one or more tangible, non-transitory, computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code and/or executable instructions embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer (device), partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
This application claims the benefit and priority of U.S. Patent Application Ser. No. 62/129,402, filed Mar. 6, 2015 and entitled MONITORING OPERATION OF A REACTION CHAMBER, the entirety of which is incorporated herein by reference.
Number | Date | Country | |
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62129402 | Mar 2015 | US |