[0001] This application claims the benefit of U.S. Provisional Application Serial No. 60/365,782 filed Mar. 21, 2002, expressly incorporated herein by reference; and U.S. Provisional Application Ser. No. 60/298,878 filed Jun. 19, 2001, expressly incorporated herein by reference.
[0002] 1. Field of the Invention
[0003] The present invention concerns computer-implemented and/or computer assisted methods, systems and mediums for enabling improved control (e.g., parallel control) during advanced process control. More specifically, one or more embodiments of the present invention relate to enhanced control of the processing of products, such as semi-conductor wafers, on comparably configured processing devices, such as chambers, utilizing behavior information.
[0004] 2. Related Art
[0005] Microelectronic products, such as semi-conductor chips, are fabricated in foundries. In a foundry, batches of products are typically fabricated in parallel on assembly lines using identically configured components such as, e.g., chambers, tools, and modules (e.g., a grouping of tools). The intention is that these assembly lines will produce batches of identical products. Typically, each of these products are made by utilizing a multitude of recipes, where each recipe may be thought of as a set of predefined process parameters required to effectuate a processing outcome.
[0006] It is also often the case that a batch of products, such as a small lot of specialized chips, are produced, and then the next batch of the same type of product is produced minutes, hours, days, weeks or even months later. This later parallel batch could be produced on the same or different assembly line. Despite the time lapse, it is intended that the products in these batches will be identical.
[0007] Though it may be desired that, in the situations mentioned above, the results of a particular recipe (and, where the sum total of the recipes are the same, the final products themselves) be identical from batch to batch, this in fact might not necessarily occur. One reason is because differences in the raw materials that are used from one batch of wafers to another may emerge. For example, one shipment of a raw material may contain chemical impurities that do not exist in a subsequent shipment.
[0008] Another reason for lack of identical results concerns those situations where the manufacture of two different products happens to involve the use of at least one recipe in common (but where, e.g., the recipes used prior to the common recipe for each product differs). Though two different end products may be the ultimate goal, it is still desirable for the specific common recipe to have the same specific result when used in the course of manufacturing each of the two products. However, in reality, the effect of the common recipes may differ somewhat, due to the fact that the processing tools had, prior to the common recipe steps, been performing different tasks in the course of manufacturing each of the two products. E.g., prior to implementing the common recipe, a tool manufacturing product X may have been tasked to provide a relatively deep etch, whereas a tool manufacturing product Y may have been tasked to provide a relatively shallow etch prior to implementing the common recipe. Thus, the ability of a processing tool to reset itself to perform a specific task may be affected by the type of task it had previously been performing.
[0009] When situations such as those mentioned above occur and cause the tools to produce results not otherwise desired by the recipes, techniques exist to allow appropriate modifications to be made to the tool settings. However, if one were to contemplate conveying those modification settings to, e.g., other tools on another assembly line making the same product, a problem one would encounter is that each component of an assembly line, e.g., chambers, tools and modules, is adjusted separately and independently, even though the same product is being fabricated in parallel on another assembly line. While modifications made to one tool or chamber on, e.g., one assembly line could be manually matched in another tool or chamber on, e.g., another assembly line (or re-used on the same assembly line at a later time), no method or process currently exists to provide for automated communication of the modification. These types of communication problems also exist with regard to components on the same assembly line, as well as sub-components on the same component (and even regarding use of the same component or sub-component at different times).
[0010] Consequently, what is needed is an improved scheme for capturing desired behaviors (e.g., parameter settings) of components, and communicating those behaviors to other (and/or later used) components to, e.g., improve consistency of the results of given recipes (or other instruction-based entities).
[0011] The present invention addresses the deficiencies of the conventional technology described above by, e.g., capturing behaviors of one or more assembly line components, and communicating those behaviors to appropriate components of, e.g., other assembly lines within a foundry to, e.g., improve the consistency of the results of a given recipe(s) from use to use. Thus, aspects of the present invention provide for a better form of control among comparably configured processing devices handling parallel workstreams. Accordingly, one or more embodiments of the present invention provide for sharing and/or reuse of behavior information for better control of, e.g., foundry components, even when parallel processing is spaced apart time wise.
[0012] It is envisioned (by one or more embodiments of the present invention) that the present invention can be used in the production of a micro-electronic device using a series of “parallel” assembly lines, where each assembly line includes one or more entities being and/or containing one or more components (e.g., chambers, tools and/or modules) that are configured identically to components of at least one other assembly line. In operation, for example, the component behaviors and the model and/or recipe parameters for converging the results of processing are collected as a first batch is processed by one of a number of components in an assembly line to produce at least one type of micro-electronic device. The information relating to the collected behavior is then shared among identically configured components in another assembly line to produce a second batch of that type of micro-electronic device(s). In one or more embodiments of the present invention, the aforementioned second batch may also be produced later in time (using the behaviors and model parameters collected during production of the first batch) by one or more components of the same assembly line (or same stand-alone component) as produced the first batch. The present invention also provides, according to one or more embodiments, for extrapolating model parameters for a portion of the assembly line, such as one of the processing devices, to a product (whether same, similar or different) with a similar initial model for that part of the assembly line.
[0013] In accordance with one or more embodiments of the present invention, there are provided methods, systems and computer programs for converging, to a target setting, results generated by one or more semi-conductor processing entities including (or itself acting as the) at least one comparably configured component. The present invention includes collecting data representative of one or more behaviors of at least one of the one or more processing entities, said one or more behaviors being collected in the course of the results of the one or more processing entities converging to (or attempting to maintain proximity with) the target setting. The present invention also includes sharing information relating to the data representative of the one or more behaviors with the one or more processing entities from which the data was collected, wherein the sharing of the information facilitates the one or more processing entities receiving the data to converge to (or to attempt to maintain proximity with) the target setting.
[0014] In accordance with one or more embodiments of the present invention, the sharing of the information is performed on a wafer-to-wafer basis, and/or performed on a run-to-run basis.
[0015] Collecting data may optionally include measuring the at least one device on a metrology tool. Converging may optionally include adjusting a process parameter for at least one of the comparably configured components subsequent to measuring of the at least one device and prior to processing of a next device.
[0016] According to one or more embodiments of the present invention, collecting data includes measuring the at least one device in a batch of devices on a metrology tool, and sharing includes adjusting a process parameter for at least one of the comparably configured components subsequent to measuring of the batch and prior to processing of a next batch.
[0017] According to one or more embodiments of the present invention, the comparably configured components are on a same semi-conductor processing entity; and/or the comparably configured components are on at least two semi-conductor processing entities.
[0018] Optionally, the adjustment is performed on a same processing entity at substantially different processing times. Optionally, the adjustment is performed on a different processing entity, at a substantially different processing time and/or a substantially same processing time.
[0019] Optionally, sharing includes modifying a recipe for at least one of the comparably configured components subsequent to measuring of the batch and prior to processing of a next batch.
[0020] Optionally, the semi-conductor processing entity includes an integrated metrology tool, and/or a separate metrology tool is provided for the semi-conductor processing entity.
[0021] According to one or more embodiments of the present invention, the at least one semiconductor processing entity may be controlled from a controller.
[0022] The above mentioned and other advantages and features of the present invention will become more readily apparent from the following detailed description and the accompanying drawings, in which:
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[0044] The following detailed description includes many specific details. The inclusion of such details is for the purpose of illustration only and should not be understood to limit the invention. Throughout this discussion, similar elements are referred to by similar numbers in the various figures for ease of reference. In addition, features in one embodiment may be combined with features in other embodiments of the invention.
[0045] A process control system, such as a semi-conductor fabrication plant, may include process tools each perhaps with multiple chambers, wherein each of the chambers is intended to work in parallel on a stream of products, to produce essentially identical products or products where at least some of the processing is essentially identical. One or more embodiments of the present invention concern matching (e.g., imparting the behavior information of one component to another component) between one or more comparably configured components (e.g., chambers on one or more process tools) where products are processed in parallel. One or more embodiments of the present invention also provides for matching where the products are processed at different times, perhaps on the same or different process tool(s). The designation “parallel” is used to indicate that two (or more) streams of products are being subjected to at least some comparable processing (e.g., parallel assembly lines), whether at more or less the same time or at different times.
[0046]
[0047] A batch of wafers processed by the process tool
[0048] With some process control to control and/or coordinate the configuration of the chambers
[0049]
[0050] Reference is made to
[0051] The match could be at the chamber level or it could be at the tool level. That is, it could be matching just a chamber, it could be matching any two or more chambers on the same tool or any two or more chambers on different tools or the same chamber on the same tool at a later time, providing they are the same kind of chamber running the same kind of process. Also, one can match the whole tool performance to two (or more) separate tools of the same type, provided they are identical copies.
[0052] Reference is made to
[0053] Reference is made to
[0054] The APC
[0055]
[0056] Reference is made to
[0057] The SMC software that performs the actual process control computation, according to these implementations, is on a stand alone computer
[0058] Whether or not the process tool
[0059] In the second implementation
[0060] The third implementation
[0061] Reference is made to
[0062] Reference is made to
[0063] As illustrated in
[0064] There are up to three chambers on a typical Producer (TM) tool; therefore there are up to six processing stations. So using one or more embodiments of the present invention, one could cause any combination of two or more of those processing stations, even all six processing stations, to converge to the target. Other tools with which the invention might be used might have any number of chambers, with single, double or more wafer processing capacity. The measured stress results are an indication of film integrity. If there is a high stress in the film, the film is more likely to crack or peel or have other defects; hence, typically there is a target stress value as well as a target thickness. There is also a target refractive index (RI) value. While adjusting the thickness under control it is preferable not to negatively affect some other target film property such as stress or RI.
[0065] The results in the graph of
[0066] The left axis of the graph shows thickness measurements in angstroms that are taken from wafer pairs from different matched chambers. The right axis shows processing time consumed for RF processing of each wafer, the processing time being the parameter that is being adjusted.
[0067] The RF time,
[0068] In order to match these two chambers, the system adjusts the right and left RF time
[0069] Still referring to
[0070] When new lot
[0071] In this particular example, the system can affect the RF time to adjust the film thickness. (RF is a wafer treatment for depositing film wherein the chamber energizes certain gases therein for a period of time to cause the deposition of film on the wafer.) In other types of processing, other model or recipe parameters would be adjusted to achieve desired different results. Although the example of
[0072] Reference is made to
[0073] In this example, the spacing between the wafer and the shower head is being adjusted to achieve the match. In the previous example, time was adjusted to achieve the match. As shown in the graph of
[0074] The APC determines the amount of adjustment to be made, according to one or more embodiments, by use of any available model that describes the process. One appropriate model that determines an adjustment is the iAPC configuration option, available from Applied Materials, in connection with tools sold under trademarks including Producer(TM), Centura(TM), Mirra (TM), Reflexion (TM) or Endura(TM). According to one such model, the first wafer is run on the process tool and then the result is measured on the first wafer; the measured result is entered into the model. The model computes what the result should have been, compares it to the actual result, and determines a different set of processing conditions, if any, that would theoretically meet the target. That information includes an adjustment in the recipe for the next wafer. In the time it takes the robot to move the next wafer into the chamber, the calculations are done, the new recipe set point (including the adjustment) is determined, and the adjustment to the process tool is made.
[0075] Reference is made to
[0076] A unique model is built for each process and subsequently stored and made available for later reference. Hence, the model illustrated here would be different for other devices. For example, the input parameters could differ. On an etch tool, as one example, the typical adjusted parameters could include RF time, power, and/or one or more gas flow rates. There might be three or four or even more different input parameters, and likewise the outputs that are measured will differ. These and other models for determining adjustments are commercially available, as mentioned above.
[0077] Reference is made to
[0078] Reference is made to
[0079] Reference is now made to
[0080] Reference is now made to
[0081] Reference is now made to
[0082] Reference is made to
[0083] Reference is now made to
[0084] Reference is now made to
[0085] Reference is now made to
[0086] According to one or more embodiments, steps
[0087] The behavior information has been provided in some manner, such as a broadcast from a parallel processing tool, or central storage for example. If there is appropriate behavior information, at step
[0088] At step
[0089] At step
[0090] In connection with the flow chart of
[0091] While this invention has been described in conjunction with the specific embodiments outlined above, many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth are intended to be illustrative and not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the following claims.
[0092] The invention has been described in connection with specific process tools, although other examples of process tools have been provided. It is not intended to limit the invention to these specified process tools. More specifically, this invention is intended to accommodate any process tool, including any type of process tool used in manufacturing semi-conductors.
[0093] As another example, the advanced process control may be implemented on a general purpose computer or on a specially programmed computer. It may also be implemented as a distributed computer system, rather than a single computer system. Further, some of the distributed systems might include embedded systems; the programming may be distributed among processing devices and/or metrology tools and/or other parts of the process control system.
[0094] Similarly, the processing may be controlled by software on one or more computer systems and/or processors and/or process tools, or could be partially or wholly implemented in hardware. Moreover, the advanced process control may communicate directly or indirectly with relevant metrology tools and processing tools, or the metrology tools and processing tools may communicate directly or indirectly with each other and the advanced process control.
[0095] Further, the invention has been described as being implemented on a closed network. It is possible that the invention could be implemented over a more complex network, such as an Intranet, the Internet, or it could be implemented on a single computer system. Moreover, portions of the system maybe distributed (or not) over one or more computers, and some functions maybe distributed to other hardware, such as tools, and still remain within the scope of the invention.