Data processing: generic control systems or specific application – Specific application – apparatus or process – Product assembly or manufacturing
Reexamination Certificate
1998-09-04
2001-05-01
Grant, William (Department: 2121)
Data processing: generic control systems or specific application
Specific application, apparatus or process
Product assembly or manufacturing
C438S014000
Reexamination Certificate
active
06226563
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for controlling equipment in a semiconductor manufacturing system, and more particularly, to a method for automatically controlling process conditions that reflect actual operational capabilities of units within the equipment, through an unit monitoring module, to maximize the productivity of the system.
2. Description of the Related Art
Generally, the fabrication of semiconductor devices involves highly precise processes that require finely tuned precision equipment. Several pieces of precision equipment are typically employed in sequence and arranged on a semiconductor processing line. The operation of each piece of precision equipment on the line is closely monitored by operators to maintain and enhance the efficiency of the processing line.
As shown in
FIG. 1
, conventional fabrication equipment
3
are disposed on a conventional processing line. When a lot (not shown) of workpieces, such as wafers, are introduced into the equipment
3
, the equipment
3
performs a fabrication process on the lot. The equipment
3
is connected on-line to a host computer
1
through an equipment server
4
. An operator interface (O/I)
2
, for example an operator interface personal computer (O/I PC), is also connected on-line to the host computer
1
. Through the O/I
2
, an operator informs the host computer
1
that a process using the equipment
3
is about to commence. The operator inputs basic manufacture data into the host computer
1
, e.g., the identification number (ID) of the lot to be processed in the equipment
3
and the ID of the equipment
3
for performing the process with the lot.
Then, based on the input basic manufacture data, the host computer
1
searches its data base for the process condition data to be applied to the process on the lot. The host computer
1
immediately downloads these process condition data, including preset process settings, to the equipment. Process settings may include, for example, a desired process time duration or a desired process temperature.
Thereafter, the operator checks the process condition data and inputs a process commencing command or a process terminating command. The lot is then automatically and rapidly routed into and out of the equipment
3
. In this manner, the process equipment
3
performs on the workpieces of each lot based on the process settings received.
The equipment
3
performs the processes on the lots by operating units or components of the equipment
3
, e.g., loading and unloading ports (not shown), and chambers
5
. While the equipment
3
performs the process on the lots, the operator closely monitors the operations of the units of the equipment
3
continuously. If it is recognized that a particular unit, e.g., a particular chamber
5
, of the equipment
3
is in an non-operational state, because, for example, the particular unit is undergoing preventative maintenance or it is out of order, then the whole equipment is determined to be in the non-operational state. Consequently, the equipment is turned off to prevent production problems associated with introducing lots into non-operational chambers.
In the processing line, a transferring apparatus, e.g., an auto guided vehicle (AGV)
6
, is included to automatically transfer lots among the equipment
3
and between bays of the fabrication facility. The AGV
6
is controlled by commands communicated from the host computer
1
to an on-line transfer apparatus server
7
and then transmitted by the transfer apparatus server to the AGV
6
via a communications link. The host computer
1
continuously communicates operational commands to the AGV
6
so that the AGV
6
can rapidly respond to perform the lot transferring function.
However, such a conventional controlling system suffers from several problems. First, even when only some of the units of the equipment
3
are non-operational and other units are operational, the operator considers the whole equipment
3
to be in the non-operational state. As a result, the equipment
3
is not fully utilized and the productivity of the processing line is not efficiently controlled.
Secondly, since it is very difficult for the operator to recognize the actual operating states of units in real time, equipment
3
with non-operational units may be considered to be in the operational state for some period of time. During this time delay, the operator may introduce lots into the equipment with process condition data designed for normal operations. In this case, an excessive number of lots may be introduced into the equipment compared to the number the equipment can actually handle. This over-introduction of lots may result in the accumulation of lots in the equipment. When lots accumulate in the equipment, the efficiency of the entire processing line is reduced.
Thirdly, even when the operator recognizes that some units are non-operational, the AGV is operated without any intervention of the operator, so that the over-introduction and accumulation of lots in the equipment may still occur, thus increasing the chances of over-introduction.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to efficiently control the overall productivity of the equipment arranged in a processing line by recognizing the operating states of the units of the equipment automatically, in real time, and providing process condition data to the equipment according to the actual operational capability of the equipment.
It is another object of the present invention to prevent lots from being over-introduced and accumulated in the equipment by controlling the number of the lots to be introduced into the equipment according to the actual operational capability of the equipment.
To achieve the above objects and other objects and advantages of the present invention, the method for controlling equipment in a semiconductor fabrication system includes automatically receiving operational state data from equipment in a semiconductor fabrication system and determining whether the operational state data corresponding to any of the equipment is abnormal. If the operational state data is abnormal for certain equipment, it is determined whether the operational state data indicate all units of the certain equipment are in non-operational states. If all units of the certain equipment are in the non-operational states, all process condition data corresponding to the certain equipment is blocked off in the host computer, whereby the equipment is isolated from a fabrication processing flow. If all units are not non-operational, non-operational units of the certain equipment are identified, indicated by respective parameters of the operational state data having non-operational state values, and a subset of the process condition data corresponding to the non-operational unit is blocked off in the host computer, whereby the non-operational units are isolated from the fabrication processing flow.
In another aspect of the invention, the method also includes downloading an equipment state message into the certain equipment; and downloading a transferring equipment control message whereby the number of lots delivered by the transferring equipment to the non-operational units is changed.
Therefore, the present invention controls the productivity of the processing line with appropriate process conditions corresponding to the actual operational capabilities of the equipment and units thereof.
REFERENCES:
patent: 4829445 (1989-05-01), Burney
patent: 5696689 (1997-12-01), Okumura
patent: 5751582 (1998-05-01), Saxena
patent: 5862054 (1999-01-01), Li
patent: 5923553 (1999-07-01), Yi
Grant William
Hartman Jr. Ronald D
Jones Volentine, LLC
Samsung Electronics Co,. Ltd.
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