KR100223961B1 - Accumulation control system and method in the semiconductor manufacture - Google Patents

Abstract

The present invention relates to a congestion management system and congestion management method between semiconductor manufacturing processes that automatically checks the stall time required when a unit quantity of wafers move between two different process facilities to control the loading of wafers.

The present invention includes a controller for controlling wafer transfer in a lot unit, a cleaner for treating the surface of the wafer, and a diffusion path for performing a specific process when the surface-treated wafer is transferred. It is configured to be re-transferred to the cleaner, so that the first step of storing the unique code for the lot treated in the cleaner and the end time of the process associated with the cleaner and backing up the unique number before the wafer is introduced into the diffusion furnace. The second step is to calculate the required retention time and return the wafer having the retention time equal to or greater than the predetermined reference time to the cleaner.

Therefore, since the wafer is introduced into the facility in an optimal state to perform a specific process, productivity and yield are improved, and efficient management of the automated process system is possible due to accurate congestion management.

Description

Stagnation management system and stagnation control method between semiconductor manufacturing processes

1 is a process chart by the conventional semiconductor process management system.

2 is a block diagram illustrating an embodiment of a semiconductor interprocess identity management system according to the present invention.

3 is a flowchart illustrating an operation performed while the controller and the cleaner are interfaced as an embodiment of the method for managing congestion between semiconductor manufacturing processes according to the present invention.

4 is a flowchart of an operation performed while the control unit and the loading unit are interfaced as an embodiment of the method for managing congestion between semiconductor manufacturing processes according to the present invention.

5 is a flowchart illustrating an operation performed while the control unit and the diffusion path are interfaced as an embodiment of the method for managing congestion between semiconductor manufacturing processes according to the present invention.

* Explanation of symbols for main parts of the drawings

10 cleaner 12 loading unit

14: diffusion path 16: control unit

The present invention relates to a congestion management system and a congestion management method between semiconductor manufacturing processes, and more particularly, to control the loading of wafers by automatically checking the stall time required when a unit quantity of wafers moves between two different process facilities. It relates to a congestion management system and a congestion management method between semiconductor manufacturing processes.

In general, a semiconductor device in which a wafer is made of a substrate is sequentially subjected to a plurality of multi-step processes such as oxidation, diffusion, deposition, ion implantation, and photolithography. Equipment is installed for each manufacturing line.

Each individual fixture is usually processed by statistical process control method, and the operator writes process characteristics, process start and end time on the run sheet, and manages and continues the equipment with reference to the description. The process is taking place.

After the process is completed in these individual fixing facilities, the wafer is transferred to the facility for subsequent processing, and the delay time of loading due to the transfer or accumulation occurs for the specific wafer. As a result, the surface of the wafer may be a major cause of changing the state of a given wafer by performing a pre-process.

A concrete example is demonstrated with reference to FIG.

In the semiconductor wafer, processes for forming films such as gate oxide, gate poly, pocl, nitride, cap, s-poly, and p-poly are continuously performed.

The same process as described above occurs almost in the diffusion furnace, and the wafer is cleaned before being introduced into the diffusion furnace.

That is, after cleaning the surface of the wafer with a pre-diffusion cleaner (S2), the operator writes the cleaning time on the run sheet for the specific wafer (in the case of the lot unit) and waits (S4). Means the time taken for the transfer to be comprehensive and includes loading time according to the accumulation of wafers to be processed in the diffusion furnace. Generally, about 30 minutes is set as the time limit after the cleaning before performing the diffusion process or the oxide film growth. The restriction of the retention time is managed to prevent the oxide film from growing by the nitride film rather than the oxide film by the interlayer heat treatment.

Therefore, when the wafer is introduced into the diffusion furnace, the operator checks the corresponding cleaning time described in the run sheet in step S6, calculates the waiting time, and determines whether the wafer is suitable for performing the process.

If it is determined by the subjective judgment of the worker that the stagnation time has not exceeded the time limit, the worker inputs the wafer into the diffusion path in step S8 to proceed with the process. It is judged that an unnecessary metal film or oxynitride film is formed and is recleaned in step S10.

As described above, the determination of the conventional recleaning depends on the subjective judgment of the operator, and even when a standard of its own is set, error of calculation, error of process, etc. may occur, so that the change of characteristics of the semiconductor device or the decrease of the yield may occur. There was a problem that occurred.

SUMMARY OF THE INVENTION An object of the present invention is to provide a congestion management system between semiconductor manufacturing processes for checking the stagnation time occurring in the middle of the transfer from the specific process to the subsequent process so as not to affect the wafer during the subsequent process.

Another object of the present invention is to check the stagnation time required during the transfer to the diffusion furnace after cleaning the wafer, and to manage the stagnation between semiconductor manufacturing processes to prevent the stagnation of the wafer for a certain time or more. To provide a way.

In order to achieve the above object, the congestion control system between semiconductor manufacturing processes includes a cleaner for cleaning a surface of a wafer to perform a subsequent process, a diffusion furnace for diffusing or oxidizing a wafer loaded from the cleaner, The loading unit for holding the wafer taken out from the cleaner in the standby state and selectively loading the cleaner or the diffusion furnace under the control of the control means, and the stagnation time from the cleaner to just before being taken out into the diffusion furnace is determined by the reference retention time. In contrast, a control means for controlling the operation of the loading unit such that the wafer is returned to the cleaner when the stagnation time elapses and the wafer is loaded into the diffusion furnace when the stagnation time has not elapsed.

The control means registers the process completion time of the cleaner in a code marked for wafer classification or lot classification of the wafer, so that the predetermined reference dwell time is calculated and controlled by the difference between the current time and the process completion time. This is preferred.

The control unit may further include an alarm unit configured to perform an alarm when the waiting time of the wafer passes the reference stagnation time.

In the semiconductor manufacturing process according to the present invention, the congestion control method, a control unit for controlling the transfer of the lot, a cleaner for treating the surface of the wafer for each lot, and the diffusion to perform a specific process when the lot is transferred after the wafer surface treatment A method for managing congestion between semiconductor manufacturing processes including a furnace and controlling the transfer of the diffusion furnace from the cleaner, the method comprising: storing a unique code for a lot surface-treated in the cleaner and a process termination time in the cleaner; A first step and a second step of returning the lot to the cleaner if the stagnation time is longer than a predetermined reference time by calculating the stagnation time required for the transfer by backing up the lot number before the lot is introduced into the diffusion path. It is made.

The method may further include a third step of checking the process end time while the cleaner is being loaded into the diffusion furnace and returning the corresponding lot to the cleaner when the stagnation time is longer than a predetermined reference time.

In the second step, when the stall time of the corresponding lot is greater than or equal to a predetermined reference time, the operation of the diffusion path may be interlocked.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 2, an embodiment of the identity management system between semiconductor manufacturing processes according to the present invention is configured such that a lot of wafers are cleaned in the cleaner 10 and then transferred to the loading unit 12. In 12), the stagnant and standby wafers are configured to be re-transferred to the cleaner 10 or transferred to the diffusion path 14.

The control unit 16 is configured to interface with the cleaner 10, the loading unit 12, and the diffusion path 14. That is, the controller 16 backs up the unique number of the cleaned wafer from the cleaner 10, and re-cleans the cleaner 10 for exceeding the time limit among the wafers of the lot loaded in the loading unit 12. It controls the transfer, and checks the unique number of the wafer of one lot that is transferred into the diffusion path 14, and interlocks the operation of the diffusion path 14 when the wafer exceeding the time limit is transferred inside. It is configured to.

With the above-described configuration, the implementation of the method for managing congestion between semiconductor manufacturing processes according to the present disclosure is also performed as shown in FIGS. 3 to 5.

First, a lot of wafers for forming a film, such as gate oxide, gate poly, gate poly, pdcl, nitride, cap, s-poly or p-poly, are cleaner 10. The surface is cleaned at, and when the cleaning is completed, the cleaner 10 reads the code for the corresponding lot and transmits the code to the controller 16. At this time, the code for the lot may be marked so as to be divided into a wafer carrier (not shown), and the cleaner 10 reads the code marked on the wafer carrier and transmits the code to the controller 16.

Then, when the controller 16 determines that there is a cleaning lot by performing the drawing S22 that interfaces with the cleaner 10 in step S20 as shown in the third diagram, the controller 16 backs up the lot number when the cleaning is completed by performing step S24. In step S26, the cleaning completion time for the corresponding lot is stored.

In the cleaner 10, the waiter of the lot unit in which the cleaning is finished is transferred to the diffusion furnace 14 immediately if there is no lot in process in the diffusion path 14, but the lot in process in the diffusion path 14 is removed. If there is, it is accumulated in the standby state in the loading unit 12.

In the loading unit 12, the lots are stacked in the order of loading from the cleaner 10, and when the process preparation for the other wafers in the diffusion path 14 is completed, the lots are transferred in the stacked lot order. The lot number of the wafer in the lot unit accumulated in the loading unit 12 is frequently checked and transmitted to the control unit 16.

Then, the controller 16 checks the cleaning completion time for the lot number transmitted from the loading unit 12 in step S30 as in the fourth diagram, and calculates the waiting time in step S32. The waiting time is the time that the cleaning completion time is subtracted from the current time.

As described above, the standby time is a reference time determined for congestion management, which may be set in consideration of the time when the unnecessary metal film or oxynitride film is formed on the wafer rather than the oxide film by the interlayer heat treatment.

As an embodiment according to the present invention, the limit of the waiting time is set to 30 minutes on the assumption that general oxidation and diffusion are performed in the diffusion furnace 14.

Accordingly, the controller 16 checks whether the calculated waiting time is 30 minutes or more, which is a preset waiting time, in step S34. When 30 minutes or more have elapsed, the controller 16 controls the loading unit 12 to perform the corresponding step in step S36. Transfer the lot to the cleaner (10). The wafer transferred to the cleaner 10 is then recleaned and loaded back into the diffusion path 14.

In addition, the wafers that do not exceed the preset waiting time in the loading unit 12 are sequentially transferred into the diffusion path 14 for process progress, wherein the diffusion path 14 and the control unit 16 are interfaced to the last standby. Check the time.

That is, the control unit 16 interfaces with the diffusion arc 14 in step S40 to back up the unique number of the wafer of the specific lot transferred into the diffusion path 14, and the uniqueness of the input wafer as it is interfaced in step S40. After checking the cleaning completion time for the number in step S42, the waiting time is calculated as the difference between the current time and the cleaning completion time in step S44.

If the waiting time calculated in step S44 has passed 30 minutes, which is a preset reference time, and the control unit 16 checks in step S46, and when 30 minutes, which is a preset reference time, passes, step S48, the controller 16 diffuses. A control signal is output to the furnace 14 to intercross the operation of the diffusion path 14. Then, the controller 16 continuously performs S50 to generate an alarm.

The operator can then acknowledge the alarm and take appropriate action on the diffusion path 14.

Of course, it may be configured to return the specific lot to the cleaner 10 in accordance with the intention of the manufacturer in place of the alarm operation made in step S50.

In the embodiment, the process of cleaning the wafer before the process is performed in the diffusion furnace to form a film such as a gate oxide, a gate poly, a fockle, a nitride film, a cap, an S-poly or a P-poly has been described. If a plurality of processes are made in series, and a lot of accumulation time is taken as the accumulation occurs in the transfer of the process equipment, the same may be applied to all cases affecting subsequent processes.

Then, since the wafer is introduced into the facility in an optimal state to perform a specific process, productivity and yield are improved, and efficient management of the automated process system is possible due to accurate congestion management.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications are within the scope of the appended claims.

Claims (11)

(Cleaning) A cleaner for cleaning the surface of a wafer to perform a subsequent process, comprising: a diffusion furnace for diffusing or oxidizing a wafer loaded from the cleaner; A loading unit for holding the wafer taken out from the cleaner in an atmospheric state and selectively loading the cleaner or diffusion path under the control of a control means; And the wafer is returned to the cleaner when the stagnation time elapses from the stagnation time to the stagnation time compared to the stagnation time until the withdrawal time from the cleaner and immediately before being loaded into the diffusion furnace. And control means for controlling the operation of the loading unit to load the wafer into the diffusion furnace. delete delete delete delete (Correction) The method according to claim 1, wherein the control means lists the process completion time in the cleaner in a first code marked for distinguishing wafers by wafer, so that the predetermined reference dwell time is equal to the current time and the process completion. Identity management system between the semiconductor manufacturing process, characterized in that the control is calculated by the difference in time. (Correction) The method according to claim 1, wherein the control means registers the process completion time in the cleaner in a first code marked for the lot-by-lot division of the wafer, whereby the predetermined reference dwell time is the current time and the process completion. Identity management system between the semiconductor manufacturing process, characterized in that the control is calculated by the difference in time. 2. The identity management system of claim 1, wherein the control means further comprises an alarm means for alarming when the waiting time of the wafer passes the reference stagnation time. A control unit for controlling the transfer of the lot, a cleaner for treating the surface of the wafer for each lot, and a diffusion path for performing a specific process when the lot is transferred after the wafer is surface treated, thereby transferring the cleaner to the diffusion path. A method for controlling identity among semiconductor manufacturing processes to control, comprising: a first step of storing a unique code for a lot surface treated in the cleaner and a process end time in the cleaner associated with the unique code; And a second step of backing up the corresponding lot number before inputting the lot into the diffusion path, calculating a stagnation time required for the transfer, and returning the lot to the cleaner if the stagnation time is equal to or greater than a predetermined reference time. Congestion control method between the semiconductor manufacturing process, characterized in that made. 10. The method of claim 9, further comprising the step of returning the lot to the cleaner if the stagnation time is greater than a predetermined reference time by checking the end time of the process during loading from the cleaner to the diffusion furnace. Stagnation control method between the semiconductor manufacturing process. 10. The method of claim 9, wherein the second step interlocks the operation of the diffusion path when the stall time of the corresponding lot is equal to or greater than a predetermined reference time.