JP2010113515A - Production management method and production management system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production management method and a production management method for easily and properly determining the priority of a lot. <P>SOLUTION: On the basis of the finished planning date and time of a first lot when prescribed processing is successively executed in a plurality of processs held by a production line, a current process date and time when the first lot exists in the current process, and the total value of processing time in the residual processs of the first lot, the priority of the first lot is calculated. The priority of the lot is expressed by, for example, residual working magnification, and the residual working magnification is calculated by the following formula (1): the residual working magnification=(finished planning date and time-current process date and time)/the total value of the processing time in the residual processs. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a production management method and a production management system.

A semiconductor device production line usually has several tens to several hundreds of processes, and it takes about one to three months from the introduction of a wafer serving as a substrate of the semiconductor device into the production line until the semiconductor device is completed. . In the meantime, unexpected situations (stagnation) that affect production activities such as insufficient capacity of the process that becomes the bottleneck (also called the neck process), suspension due to maintenance of production facilities, and unexpected troubles may occur. It is not uncommon, and there are many difficulties in completing production without delay in our planned schedule.
In such a production line, various methods have been conventionally employed in order to flow a large number of lots as smoothly as possible. For example, as described in the prior art of Patent Document 1, there are a method focusing on first-in first-out and a method focusing on the neck process. There is also a method of changing and determining the priority of a lot each time according to changing order information and production status. In other words, in order to ensure delivery time and quantity, production results of production lines that require a long time are checked at intermediate specific production points, the difference between the result and the target is calculated, a new production schedule is created, and production is started. It is a way to continue.
JP 10-149205 A

However, changing the priority of each lot according to the production status of the manufacturing process that changes from day to day will cause confusion at the production site, resulting in a decrease in productivity of the entire production line and deterioration of the lead time of the entire production line. As a result, there was a possibility that the customer delivery date could not be kept.
In addition, a large computer was used to calculate and simulate production instructions, and a long time calculation was required. That is, there is a problem that enormous amounts of calculations are required to schedule all the lots in the factory for each process and to determine the priority order for each lot every day.
Accordingly, some aspects of the present invention have been made paying attention to such a problem, and a production management method and a production management system capable of easily and appropriately determining the priority of a lot. For the purpose of provision.

In order to achieve the above object, a production management method according to an aspect of the present invention includes a completion date and time of a first lot on which a predetermined process is sequentially performed in a plurality of steps of a production line, and the first lot Calculating the priority of the first lot based on the current process date and time when the lot exists in the current process and the total processing time in the remaining process of the first lot; It is characterized by having.
Further, in the above production management method, the completion schedule date and time of the second lot sequentially subjected to predetermined processing in a plurality of steps of the production line, and the second lot is the same as the first lot Calculating the priority of the second lot based on the current process date and time when present in the current process and the total processing time in the remaining process of the second lot; and A step of comparing the priority of the first lot with the priority of the second lot, and processing the higher one of the first lot or the second lot first. It may be characterized by including.

In the above production management method, the priority is calculated by dividing a value obtained by subtracting the current process date from the completion plan date by a total value of processing times in the remaining processes. It is also good.
In the above production management method, the priority in the current process may be adjusted according to the status of the process subsequent to the current process.
In the production management system according to another aspect of the present invention, the completion date and time of the first lot on which a predetermined process is sequentially performed in a plurality of processes of the production line, and the first lot exists in the current process Based on the information acquired by the acquisition means, the acquisition means for acquiring information relating to the current process date and time, the total value of the processing time in the remaining process of the first lot, It has a calculation means for calculating the priority of the first lot, and a display means for displaying the priority calculated by the calculation means.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that, in each drawing described below, parts having the same configuration are denoted by the same reference numerals, and redundant description thereof is omitted.
(1) First Embodiment FIG. 1 is a block diagram showing an example of a production management system 100 according to an embodiment of the present invention. A production management system 100 shown in FIG. 1 is a system that calculates the priority of a lot in each process of a production line. Here, the production line is, for example, a production line for semiconductor devices, and includes a pre-process, a post-process, an inspection process, or at least two of these processes. The pre-process is also called a wafer process, and includes an ion implantation process, an oxidation diffusion process, a film formation (CVD: Chemical Vapor Deposition) process, a photolithography process, an etching process, and the like. In the previous step, the above steps are alternately repeated, and the total number of steps is several tens to several hundreds, for example. Further, the post-process includes a dicing process, a die bonding process, a wire bonding process, a packaging process, and the like.

The production management system 100 shown in FIG. 1 can be applied to any of the above-described pre-process or post-process, or the pre-process and post-process. For example, the input device group 1 and a host CPU (Central Processing Unit). 2, a database 3, a personal computer (hereinafter referred to as calculation PC) 4 for calculating the priority of the lot, and an output device group 5.
Among these, the input device group 1 is composed of input devices arranged in each process constituting the production line. For example, the A process input device 1a, the B process input device 1b, the C process input device 1c,. Have. When this production management system 100 is applied to the previous process, the A process is, for example, an ion implantation process, the B process is, for example, an oxidation diffusion process, and the C process is, for example, a film forming process.

  As shown in FIG. 1, the A process input device 1a, the B process input device 1b, the C process input device 1c,... Are connected to the host CPU 2 via, for example, wired or wireless connection. Thus, signals including information (ie, data) can be transmitted and received. The host CPU 2 is an electronic device that performs various numerical calculations, information processing, device control, and the like by a program, and manages the progress of all lots flowing through the production line.

  The database 3 is a collection of information on all lots existing on the production line, production status of each process included in the production line, and information on the status of the processing apparatus. For example, the database 3 includes information on the input date and time of the previous process, the history of processes performed in each process, and the process recipe (that is, process conditions) for each lot. In addition, the database 3 includes information on the completion plan date and time in the previous process (that is, the completion date and time in the production plan), the input schedule date and time in the subsequent process, and the delivery deadline to the customer for each lot. included. Further, the database 3 includes information relating to the inventory of each process, such as the lot (ie, inventory) existing in the A process, the inventory of the B process, the inventory of the C process,. Such a collection of information is stored in a storage device such as a hard disk. The storage device is connected to the host CPU 2 via, for example, a wired line, and can exchange signals including information with the host CPU 2.

The calculation PC 4 acquires information from the database 3 via the host CPU 2 and calculates the priority of lots in each process based on the acquired information. Here, the information acquired by the calculation PC 4 includes the completion plan date and time of a lot on which a predetermined process is sequentially performed in a plurality of processes included in the production line, and the lot waits in the current process or is processed. This is information relating to the current process date and time when it is being performed (that is, when it exists) and the total processing time for the remaining process of this lot. Further, the priority of the lot is expressed by, for example, the remaining processing magnification, and the remaining processing magnification is calculated by the following equation (1).
Residual processing magnification = (Completion plan date−Current process date / time) / Total value of processing time in remaining process (1)

As can be seen from this equation, the smaller the remaining machining magnification, the less the margin until the planned completion date, and the higher the order of processing in the current process (that is, the processing order).
Note that the total value of the processing time in the remaining process is, for example, the total value of the “actual” processing time in the remaining process (that is, the actual processing time in the process in which the lot is processed after the current time) And does not include transport time between processes or stagnation time. The actual processing time is the time during which processing for a lot is actually performed. For example, when a lot is started to be transferred to a processing apparatus such as an ion implantation apparatus, a diffusion furnace, or a dry etching apparatus. Until the end of the lot delivery.

  As shown in FIG. 1, the calculation PC 4 includes, for example, a calculation unit 4 that performs calculation of the remaining machining magnification, a program for executing calculation in the calculation unit 4, and a calculation result in the calculation unit 4. And a storage unit 4b for storing. The computing unit 4 is composed of a logic IC, for example. The storage unit 4b is composed of, for example, a ROM and a RAM, a hard disk, or a combination thereof. The calculation PC 4 is connected to the host CPU 2 via, for example, a wired or wireless connection, and can exchange signals including information with the host CPU 2.

  The output device group 5 includes display devices arranged in each process constituting the production line, and includes, for example, an A process display device 5a, a B process display device 5b, a C process display device 5c,. When this production management system 100 is applied to the previous process, like the input device group 1, the A process is, for example, an ion implantation process, the B process is, for example, an oxidation diffusion process, and the C process is, for example, a film forming process. It is. As shown in FIG. 1, the A process display device 5a, the B process display device 5b, the C process display device 5c,... Are connected to the calculation PC 4 through, for example, wired or wireless connection. Signals including information can be exchanged with each display device.

Next, a method for calculating the remaining processing magnification of a lot existing on the production line using the production management system 100 and determining the lot processing order based on the calculated remaining processing magnification will be described.
FIG. 2 is a flowchart showing an example of the production management method according to the embodiment of the present invention.
In step (S) 1 in FIG. 2, information for calculating the remaining machining magnification is captured. For example, when a lot (hereinafter also referred to as a first lot) reaches the step A, the ID of the first lot (that is, the lot ID), the number of wafers included in the first lot, Information about the date and time when one lot arrives at the A process (hereinafter referred to as arrival date and time), status (for example, standby), and the like are input to the A process input device. Information input to the A process is transmitted to the host CPU 2 and added to the database 3. The database 3 includes several tens to several hundreds of process names to be processed for the first lot, processing conditions in each of these processes, usable processing apparatuses (for example, number machine), and the first lot. The date and time of completion and the final customer delivery date are recorded.

  Next, the calculation PC 4 takes in the information from the database 3 in which such information is recorded. The information to be fetched is, for example, the lot ID, the arrival date / time, the completion plan date / time, and the total processing time in the remaining process for the first lot. In step (S) 1, not only the first lot but also other lots that reach the process A are captured. For example, for the second lot that has reached the A process at the same time as or before or after the first lot, the lot ID, the arrival date and time, the completion plan date and time, and the total value of the processing time in the remaining process Are taken in by the calculation PC 4.

Next, in step (S) 2 of FIG. 2, the remaining machining magnification is calculated using the calculation PC 4.
For example, the arrival date / time for the first lot is the current process date / time, and the current process date / time for the first lot, the completion plan date / time, and the total value of the processing time in the remaining process are expressed by the above equation (1). Substituting each, the remaining machining magnification is calculated. As an example, for the first lot that has reached process A, the current process date and time (in this example, the same as the arrival date and time) is 12:00 pm on January 15, and the completion plan date and time is January 30. Is 12:00 pm, and the total processing time in the remaining process is 168 hours. In this case, since the completion plan date-current process date is (30-15) × 24 = 360 hours, the remaining processing magnification of the first lot is 360 / 168≈2. 1 is calculated.

Similarly, the remaining processing magnification is calculated for the second lot. As an example, for the second lot that has reached process A, the current process date and time (in this example, the same as the arrival date and time) is 12:00 pm on January 15, and the completion plan date and time is January 25. Is 12:00 pm, and the total processing time in the remaining process is 120 hours. In this case, since the completion plan date-current process date is (25-15) × 24 = 240 hours, the remaining machining magnification of the second lot is 240/120 = 2. Calculated as zero. Such calculation is performed by the calculation unit 4 of the calculation PC 4, and the calculated remaining machining magnification is stored in the storage unit 4 b of the calculation PC 4.
Next, in step (S) 3 of FIG. 2, the remaining machining magnification calculated by the calculation PC 4 is displayed. For example, information relating to the remaining machining magnification of the first lot and information relating to the remaining machining magnification of the second lot are transmitted from the calculation PC 4 to the A process display device 5a. In addition, other information related to each lot is transmitted from the host CPU 2 to the A process display device 5a via the calculation PC 4 (or directly from the host CPU 2).

  FIG. 3 is a diagram illustrating an example of a screen display by the process display device. As shown in FIG. 3, for example, on the screen of the A process display device 5a, the process name of the A process (process I), the process name (process II) that further classifies the process I, and the model of the first lot (Product type) name, lot ID, number of wafers constituting the lot, status (state), processing condition, number of the processing apparatus used, remaining processing magnification, lot priority, Is displayed. As shown in FIG. 3, when viewing this screen display, it is possible to easily grasp the status of each of the A process inventory (that is, a plurality of lots reaching the A process) together with the remaining processing magnification. .

  In FIG. 3, P + S / D in the column of Step II indicates an ion implantation step for forming the source and drain of the P-channel MOS transistor, and N + S / D indicates the source of the N-channel MOS transistor. The ion implantation process for forming a drain is shown. PWell in the same column indicates an ion implantation process for forming a P-type well diffusion layer, and NWell indicates an ion implantation process for forming an N-type well diffusion layer. Further, in FIG. 3, for a status of standby (that is, unprocessed), the number 0 (zero) is displayed in the column of the machine number of the processing apparatus.

  Next, in step (S) 4 of FIG. 2, the in-process order (ie, priority order) in the A process is determined based on the remaining machining magnification displayed on the screen of the A process display device 5a. As the numerical value of the remaining machining magnification is smaller, the margin until the planned completion date is less. Therefore, in this step (S) 4, in principle, the processing is performed from the smallest remaining machining magnification first. For example, if the remaining processing magnification of the second lot is 2.0 and the remaining processing magnification of the first lot is 2.1, the remaining processing magnification of the second lot is higher than that of the first lot. Since it is smaller, the second lot is processed before the first lot. Such comparison of the remaining processing magnification in step (S) 4 and determination of the in-process order based on the result of this comparison are performed by, for example, an operator of the A process.

  Note that the flowchart shown in FIG. 2 can be applied not only to the A process but also to the B process, the C process,. Further, the screen display example shown in FIG. 3 is applicable not only to the A process display device 5a but also to the B process display device 5b and the C process display device 5c. For example, when the example of the screen display shown in FIG. 3 is applied to the B process, the column of the process I is displayed as “oxidation diffusion”, and the column of the process II is “Well annealing”, “gate oxidation”, “S / D”. “Annealing” is displayed. As for the lots existing in each of the B process, the C process,..., The remaining machining magnification is calculated similarly to the case of the A process, and the in-process order is determined based on the calculated remaining machining magnification. Can do.

As described above, according to the embodiment of the present invention, since the priority of the lot is calculated based on the completion plan date and time, the delivery date can be observed. Further, as shown in the expression (1), the remaining machining magnification is calculated by simple calculation, so that the calculation can be completed in a short time even at the PC level. Further, in the case of the PC level, the hardware is simple and software development is easy. For this reason, the cost (namely, introduction cost) at the time of introduce | transducing said production management method or the production management system 100 into a production line can be suppressed low. Further, since it is an index having a simple meaning of the remaining processing magnification, it is easy for the operator to understand, and the priority of lots and the order of work in each process can be determined easily and appropriately.
In this embodiment, the calculation PC 4 corresponds to the “acquisition means” of the present invention, and the calculation unit 4 of the calculation PC 4 corresponds to the “calculation means” of the present invention. The output device group 5 corresponds to the “display unit” of the present invention.

(2) Second Embodiment In the first embodiment described above, in Equation (1), “the total value of processing time in the remaining process” is described as the total value of actual processing time in the remaining process. . However, the present invention is not limited to this. For example, the “total value of processing time in the remaining process” indicates the loss time (for example, the transfer time between processes and the stagnation time generated in the remaining process) in addition to the total value of the actual processing time in the remaining process. It may be included. The transport time and stagnation time are not necessarily constant values and can be shortened by improvement activities, etc., but if the loss time can be predicted to some extent accurately (for example, past experience) If the loss time in the remaining process for each lot can be predicted from the statistics), add the expected loss time to the total value of the actual processing time to obtain the value of the remaining processing magnification of the production line. Can be close to the entity.

(3) Third Embodiment In the first embodiment described above, the case has been described in which the “current process date / time” is the arrival date / time of the lot in the equation (1). However, the present invention is not limited to this. The current process date and time may be set as follows.
FIGS. 4A and 4B are diagrams illustrating examples of timings that can be set as the current process date and time. FIG. 4A shows a lot whose status is standby (that is, unprocessed), and FIG. 4B shows a lot whose status is being processed.
As shown in FIG. 4A, for the lot whose status is standby, the “current process date and time” may be the date and time when the remaining processing magnification is calculated (ie, real time). When the "current process date" is the lot arrival date or real time, all the actual process time of the current process can be included in the process time of the remaining process (solid arrows marked along the time axis) See).

  On the other hand, as shown in FIG. 4B, for the lot whose status is being processed, the “current process date and time” may be the date and time when the remaining processing magnification is calculated (ie, real time), Further, it may be the date and time when the process is started, or may be a scheduled date and time when the process is finished. When the “current process date” is the lot arrival date or the date when processing started, all the actual processing time of the current process can be included in the remaining process time (along the time axis) (See solid arrows marked as Further, when the “current process date / time” is set to real time, the remainder of the actual process time of the process can be included in the process time of the remaining process (see the broken-line arrows written along the time axis). Furthermore, when the “current process date / time” is set as the scheduled date / time for the process to be completed, the actual processing time of the process can be excluded from the processing time of the remaining process (indicated along the time axis). (See double-dotted arrows).

(4) Fourth Embodiment In the first embodiment described above, the case where the “completion plan date and time” is set as the completion plan date and time in the previous process is illustrated. Here, the completion plan date and time in the previous process means the date and time when the last process of the wafer process process is completed and the process can move to the subsequent process.
However, in the present invention, the completion plan date and time is not limited to the above example. The completion plan date and time of the present invention may be the completion plan date and time of the post-process, the customer shipping plan date, or the customer delivery date. In addition, for products that are manufactured before the wiring process, such as gate array devices, and the wiring is customized according to order specifications, the planned date and time to arrive before the wiring process of the wafer process process is provisionally set as the completion planned date and time. Also good.
In this way, the completion plan date and time of the present invention can be arbitrarily determined from, for example, the nature of the product, the customer's order form, and the production line status.

(5) Fifth Embodiment In the first embodiment described above, the calculation of the remaining machining magnification is described using Expression (1). However, in the present invention, the remaining processing magnification in the current process may be finely adjusted in accordance with the inventory status in the process subsequent to the current process, the operating status of the processing apparatus, and the like.
That is, for the first lot, it is assumed that the current process is the A process and the process processed after the A process (that is, the next process) is the B process. Even if the first lot is preferentially processed in the A process and proceeds to the B process, there are many lots in the B process having a smaller remaining processing magnification than the first lot, When the apparatus is stopped due to maintenance or the like, the first lot is stagnated for a while in the B process. In this case, processing preferentially in step A may result in waste.

  Therefore, in order to reduce such waste, before processing the first lot in the A process, the inventory status of the B process, the operating status of the processing apparatus, and the like are confirmed, and the first result is based on the result of this confirmation. The remaining processing magnification of the lot may be adjusted. For example, if many lots with a smaller remaining machining ratio than the first lot are waiting in the B process, or if the processing apparatus for the B process is stopped, + α is added to the remaining machining magnification of the first lot. Then, temporarily adjust the remaining processing magnification. Here, α is a value arbitrarily set according to the stock status of the B process and the operating status of the processing apparatus, and can be stored in advance in the storage unit 4b of the calculation PC 4.

  As an example, in the process B, when the number of lots whose remaining processing magnification is larger than that of the first lot and whose status is standby (hereinafter referred to as a third lot) exceeds a predetermined number, Α = 1 is added to the remaining machining magnification of the first lot shown in FIG. 3, and the value is changed from 2.1 to 3.1. Thereby, the priority of the first lot is lowered, and the in-process order of the first lot in the process A (that is, the current process) is lowered. After the process in the process A is completed for the first lot, + α is removed from the remaining machining magnification of the first lot, and the adjustment of the remaining machining magnification is cancelled. As a result, the above-mentioned waste can be reduced, and a large number of lots can flow more smoothly in the production line.

The figure which shows an example of the production management system 100 which concerns on embodiment of this invention. The flowchart which shows an example of the production management method which concerns on embodiment of this invention. The figure which shows an example of the screen display by a process display apparatus The figure which shows the example of the timing which can be set as the present process date.

Explanation of symbols

  1 input device group, 1a A process input device, 1b B process input device, 1c C process input device, 2 host CPU, 3 database, 4 calculation PC, 5 output device group, 5a A process display device, 5b B process display Device, 5c C process display device

Claims (5)

  Completion plan date and time of a first lot on which a predetermined process is sequentially performed in a plurality of processes of the production line, the current process date and time when the first lot exists in the current process, and the first And a step of calculating the priority of the first lot based on the total processing time in the remaining process of the lot. The completion schedule date and time of the second lot on which the predetermined processing is sequentially performed in a plurality of processes of the production line, and the second lot exists in the same current process as the first lot Calculating the priority of the second lot based on the current process date and time and the total processing time in the remaining process of the second lot;
Comparing the priority of the first lot with the priority of the second lot and processing the higher one of the first lot or the second lot first; The production management method according to claim 1, further comprising:   3. The priority is calculated by dividing a value obtained by subtracting the current process date and time from the completion plan date and time by a total value of processing times in the remaining processes. The production management method described in 1.   The production management method according to any one of claims 1 to 3, wherein the priority in the current process is adjusted according to a status of a process subsequent to the current process. Completion plan date and time of a first lot on which a predetermined process is sequentially performed in a plurality of processes of the production line, a current process date and time when the first lot exists in a current process, and the first A total value of the processing time in the remaining processes of the lot, and an acquisition means for acquiring information about
Calculation means for calculating the priority of the first lot based on the information acquired by the acquisition means;
And a display unit for displaying the priority calculated by the calculation unit.

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