Patent Application
20070010905
The present invention relates to fabrication processes and particularly to a system and method for detecting non-SECS (Semiconductor Equipment Communications Standard) processing events in processing equipments.
During semiconductor manufacture, a large amount of process data is generated. Most process or metrology equipment would generate and store process data. The described process data may specify process conditions within equipment (for example, process duration, process temperature, or process gas flow), operating conditions of the equipment (for example, alarm states, input/output (I/O) signal traces, and vacuum or pressure levels), and/or general historical data for the equipment (for example, last preventive maintenance (PM) or next PM date). Process data may also comprise various substrate feature measurements, such as film thickness mapping, particle mapping, die-to-database correlations, step height values, and line-width measurements.
Semiconductor Equipment Communications Standard (SECS) protocol is a widely used international consensus-based standard produced by SEMI (Semiconductor Equipment and Materials International). Typically, the SECS protocol communicates actively via the equipment serial port. Data available using a SECS protocol provides equipment and material information such as wafer information, wafer lot number, cassette slot number being processed, recipe name, and process parameters.
However, beyond the basic data defined in the SECS, the ability to monitor processing equipment in real time has been limited. Many processing events cannot be detected using SECS-defined process data.
Hence, there is a need for a process monitoring system that addresses the inefficiency arising from the existing technology.
A system is provided to electronically collecting and processing data obtained from processing equipment. The system comprises a data collecting device and a processor. The data collecting device collects process data obtained from equipment via a network, wherein the process data is not defined in a SECS (semiconductor equipment communication standard) protocol. The processor determines whether the collected process data conforms to a preset rule based on a historical record of process data.
A manufacturing system is provided. The manufacturing system comprises equipment, a monitoring device, and a controller. The equipment processes an article. The monitoring device, coupled to the equipment, collects non-SECS process data generated by the equipment, and screens event data from the collected non-SECS process data based on a historical record of non-SECS process data generated in preceding processing runs of the equipment. The controller receives the event data from the monitoring device, and adjusting operation of the equipment according to the event data.
A method is also provided, electronically collecting and processing data obtained from processing equipment. First, process data is obtained from processing equipment, the process data not defined in a SECS (semiconductor equipment communication standard) protocol. Next, it is determined whether the collected process data conforms to a preset rule based on historical process data.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
Exemplary embodiments of the invention will now be described with reference to
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration of specific embodiments. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. The leading digit(s) of reference numbers appearing in the Figures corresponds to the Figure number, with the exception that the same reference number is used throughout to refer to an identical component which appears in multiple Figures.
Processing tools 11 and 13 each is capable of processing at least one wafer at a time. Processing tools 11 and 13 can be any instrument, machine, or device used to perform a task or measure a characteristic or quality of a substrate or the like.
Each processing tool has an associated equipment interface connected to a network 12, such as a local area network (LAN) For example, processing tools 11 and 13 have associated equipment interfaces 111 and 131, respectively. Process data 115a and 135a generated during operation is stored in local storage unit 115 and 135 of the processing tools 11 and 13, respectively. For example, central processing unit (CPU) 113 of processing tool 11 stores process data 115a generated during operation in local storage unit 115. Similarly, central processing unit (CPU) 133 of processing tool 13 stores process data 135a generated during operation in local storage 135. When a process run is performed by a processing tool, corresponding process data is generated and stored in a local storage unit of the processing tool. When the process run is completed, the stored process data 115a is transferred to the monitoring device 15, via the network 12, for further processing.
Processing tools 11 and 13 may also comprise associated SECS interfaces (not shown). The SECS interface may be a communication port, such as an RS-232 serial port, running a SECS protocol. The SECS protocol defines details for the electronic transmission of messages between the plurality of tools and other devices within the manufacturing system 10. The SECS interface allows a limited set of process data relevant to the corresponding tool to be transmitted electronically, such as tool identifier, module identifier, wafer information, wafer lot number, cassette slot number being processed, recipe name, and process parameters etc. According to the embodiment, process data not defined in the SECS is collected and processed by the monitoring device 15 and other pertaining device, therefore, collecting and processing the SECS-defined process data is not detailed here.
The network 12 is part of a communications network within the manufacturing system 10. In one exemplary embodiment, the NETWORK 12 allows communication using Ethernet packets transmitted between the processing tools.
The monitoring device 15 is coupled to processing tools 11 and 13 via the NETWORK 12 via tool interfaces 111 and 131. When a process run is completed, the stored process data 115a is transferred to the monitoring device 15, via the NETWORK 12, for further processing. Here, the process data 115a comprises a large amount of non-SECS data, transferred according to a file transfer protocol (FTP). Historical record of process data 152 generated in a plurality of processing runs is stored in storage device 151. When process data 115a generated during a new processing run is received, the historical record of process data 152 is regarded as historical process data and used to determine whether the process data 115a comprises data specifying a processing event (hereinafter referred to as event data). When event data is detected, the event data is transferred to MES 17, and used as a reference for tool control. Additionally, the event data is transferred to an alarm system 19, whereby an alarm is generated and output via e-mail message or phone or other suitable means.
Referring to
Here, monitoring of a stepper is described as an example. For a stepper, exposure dose is a critical factor for production yield, and the exposure dose is affected by operating status of an energy sensor and spot sensor in the exposure equipment. Spot sensor and energy sensor status is typically recorded as illumination automatic calibration (ILAC) data. The ILAC data can be recorded in many types of stepper, and is generally stored in a local hard disk of the stepper. Many steppers, however, cannot report the ILAC data to an external device via a SECS protocol. The ILAC data is recorded during exposure, and stored in a local hard disk of a stepper. After exposure is performed, the stored ILAC data is transferred to a monitoring device via a network, such as a TCP/IP network using a file transfer protocol. ILAC data obtained in a plurality of preceding processes is used as a basis for statistical analysis of ILAC data of a current processing run. For example, 40 entries of ILAC data obtained during preceding processing runs of a particular illumination mode are retrieved, and a mean value thereof calculated. When the difference between the ILAC data of the current processing run and the calculated mean value exceeds a preset value, the ILAC data of the current processing run is regarded as abnormal data specifying a process event in the current processing run. When event data is identified, an alarm signal is generated. Wafers for subsequent processing may be held until the stepper is adjusted properly. The event data is stored but excluded from the historical process data, whereby the event data does not serve as a basis for a statistical analysis for a subsequent processing run.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. Those skilled in this technology can still make various alterations and modifications without departing from the scope and spirit of this invention. Therefore, the scope of the present invention shall be defined and protected by the following claims and their equivalents.
