Data processing: generic control systems or specific application – Specific application – apparatus or process – Product assembly or manufacturing
Reexamination Certificate
2002-01-18
2003-12-16
Picard, Leo (Department: 2125)
Data processing: generic control systems or specific application
Specific application, apparatus or process
Product assembly or manufacturing
C700S087000, C713S152000, C717S170000
Reexamination Certificate
active
06665575
ABSTRACT:
BACKGROUND OF INVENTION
This invention relates to software editors, and more particularly to systems for editing semiconductor-process recipes from different semiconductor-processing machines.
Advances in semiconductor manufacturing are the driving force behind increases in productivity in almost all areas of today's economy. Powerful computers and networks rely on inexpensive semiconductor integrated circuits or chips. Semiconductors are mass produced as batches of silicon wafers. The batches of wafers move through various steps of a semiconductor fabrication plant or “fab”. Each wafer may contain hundreds of thousands of individual chips.
A batch of wafers is produced by a sequence of various processing steps. Furnaces are used to grow silicon-dioxide (oxide) layers on the silicon surface of the wafers. Steppers and other photolithgraphy machines expose a layer or photo-resist on the wafer surface, while chemical baths wash away either the exposed or un-exposed photo-resist to form circuit and device patterns on the wafer. Chemical-vapor-deposition (CVD) machines and metal-vapor deposition machines deposit thin yet uniform layers on the wafer. Ion implanters drive high-energy beams of ions into the wafer, forming doped regions. Wafers processed in a fab also undergo various tests and measurements for durability, defects, and conformance with original design and process requirements. Various wafer inspection, metrology, test, and measurements tools are used.
Each of these semiconductor-processing, inspection, metrology, and measurement machines requires a set of operating instructions (a processing program) or a recipe. Recipes vary of each kind of machine, and even among different machine manufacturers for the same kind of machine. For example, and etch system manufactured by Applied Materials of Santa Clara, Calif. may require a 10-minute reaction time with a certain flow of gases, while the reaction chamber is kept at a certain elevated temperature. At the end of the 10-minute reaction time, the flow of reactive gasses are gradually reduced and replaced with inert gasses as the temperature is lowered. Another etch system manufactured by Lam Research of Fremont, Calif. may require a 15-minute reaction time in reaction chamber, with different mixture of gasses and a different temperature.
Other kinds of semiconductor-processing equipment require vastly different recipes. A furnace recipe may specify how rapidly a tray of wafers is pushed into the furnace tube while inert gas is pumped through the furnace. Then the temperature is raised to a first target. Next a reactive gas such as oxygen or silane is pumped through the furnace tube to form an oxide or poly-silicon layer. Finally some nitrogen or nitrogen-oxide may be introduced to form a capping layer of a nitride over the oxide or polysilicon. Then after a specified time, inert gas is pumped through the furnace as it cools down to a second target temperature over a specified time interval. Finally the tray of wafers are pulled out of the furnace tube at a specified rate and allowed to cool before being moved to the next process machine.
These recipes can become quite complex and varied as process engineers attempt to tweak the process for desired electrical and manufacturing-yield results. Different semiconductor products may require different recipes or combinations of steps. A dynamic-RAM process may require lighter ion-implant doses than a process for logic chips. Different oxide thicknesses require different reaction times in the furnaces.
Wide Variety of Semiconductor-Process Equipment
FIG. 1
FIG. 1
illustrates some of the semiconductor-process equipment in a wafer-fab clean room. Semiconductor-manufacturing equipment
10
includes low-pressure and plasma reaction chambers, lithography equipment, ion implanters, wafer wash stations, and furnaces, among others. Each piece of equipment
10
typically includes an embedded computer or controller for operating the equipment. The embedded computer controls reaction times, gas flow rates, temperatures, ion-implant doses and energy, and perhaps robotic movement of wafers through the equipment's reaction chambers. A video display may be included to alert equipment operators when steps have completed, and keyboards allow the operators to select recipes for use with a current batch of wafers. Bar-code readers may also be used as an input device, reading a bar code on each box of wafers.
Each of the different pieces of semiconductor-manufacturing equipment
10
has a different user interface, requiring special training for the operators and process engineers. Few, if any engineers, can operate all equipment in a fab, requiring that process engineers specialize in one or a few types of semiconductor-manufacturing equipment. Some machines may provide recipe-editing and display features, allowing a process engineer to view and edit a recipe, and manage many different recipes on the embedded computer's storage. However, the lack of a standard user interface among the different machines limits an engineer to editing recipes on just a few of the many machines.
Other kinds of factories have established file standards. See U.S. Pat. Nos. 5,828,851 and 5,838,563. Unfortunately, the extremely competitive environment for semiconductor-manufacturing equipment has prevented adoption of such standards. Instead, separate workstation computers are often used in the fab in conjunction with each process station. See U.S. Pat. Nos. 5,432,702 and 5,105,362.
While such recipe editing is useful, the editing feature of semiconductor-manufacturing equipment has been called the world's most expensive word processor. Semiconductor-manufacturing equipment can cost as much as a million dollars per machine. Use of the editing features may prevent the semiconductor-manufacturing equipment from processing wafers. This down-time is quite expensive in terms of lost wafer revenue and depreciation of the equipment. Thus is it very undesirable to edit recipes on the semiconductor-manufacturing equipment itself.
The semiconductor-manufacturing equipment is usually located inside a low-particle-density environment called a clean room. To maintain the low particle density, all persons are required to wear special clothing known as a “bunny suit”. Gloves, masks, and even breathing filters are required in some clean rooms. Typing in a recipe while wearing gloves is cumbersome, and engineers sometimes may be tempted to remove the gloves, generating particles in the clean room.
Offline Editing on a PC
FIG. 2
FIG. 2
shows transferring a recipe from a clean room to a personal computer (PC). Since editing a recipe on the semiconductor-manufacturing equipment (on line editing) is so expensive, recipes are often copied to a diskette and edited on a PC (off-line editing). Semiconductor-manufacturing equipment
10
is located in a clean-room fab and is almost continuously used for manufacturing operations. Little time on equipment
10
is available for use by the process engineer.
Semiconductor-manufacturing equipment
10
has a user interface, allowing recipes to be edited on the machine. An engineer could type in a recipe on keyboard
12
and view recipes on video display
14
, but it is more convenient to copy recipes to a floppy diskette in floppy drive
16
on equipment
10
. Diskette
18
can then be carried out of the clean-room fab and inserted into PC
20
at the engineer's office. The engineer can then edit the recipes and create new recipes, using a standard text editor or a proprietary recipe editor provided by the semiconductor-manufacturing equipment manufacturer.
These recipes can be printed on the office printer
22
. The new recipes can be copied to diskette
18
and then carried into the clean-room fab. The new recipes on diskette
18
can then be copied to the embedded computer in semiconductor-manufacturing equipment
10
using floppy drive
16
.
Different Machines Use Different Recipe Formats, Need Different Editors
Other semiconductor-manufacturing equipment
10
′ uses a
Betawar Manoj
Bhagwat Vrunda
Goradia Dinesh
Mehta Manish
Parekh Nitin
FabCentric, Inc.
Picard Leo
Rodriguez Paul
Sierra Patent Group Ltd.
LandOfFree
Recipe editor for editing and creating process recipes with... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Recipe editor for editing and creating process recipes with..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Recipe editor for editing and creating process recipes with... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3179176