Cleaning and liquid contact with solids – Processes – Including application of electrical radiant or wave energy...
Reexamination Certificate
2000-09-21
2001-05-08
Coe, Philip R. (Department: 1746)
Cleaning and liquid contact with solids
Processes
Including application of electrical radiant or wave energy...
C134S003000, C134S028000, C134S033000, C134S034000
Reexamination Certificate
active
06227212
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a semiconductor workpiece cleaning method and apparatus and, more particularly, to a semiconductor workpiece cleaning method and apparatus to be adopted or installed in a semiconductor wafer processing line to clean a semiconductor workpiece.
2. Background Art
The importance of a semiconductor workpiece cleaning process in a semiconductor device fabricating process has been increased with the fine-structured semiconductor devices. Recently, single-tank cleaning apparatus which carries out a plurality of chemical cleaning processes in one tank has often been used to reduce floor space (footprint) necessary for installing the cleaning apparatus.
Wet semiconductor workpiece cleaning apparatuses are classified roughly into immersion cleaning apparatuses which immerse a workpiece in a chemical liquid for cleaning, and spray cleaning apparatuses which spray a chemical liquid on the workpiece for cleaning.
A conventional single-tank dip type cleaning apparatus will be described with reference to FIG.
7
. In this conventional cleaning apparatus, a workpiece
2
is held fixedly on guide members
3
in a chamber
1
defined by a vessel, and a cleaning chemical liquid or pure water is supplied into the chamber
1
through a lower part of the vessel, and discharged from the chamber
1
through an upper part of the vessel to clean the workpiece
2
. Hot pure water and cold pure water are mixed in a line
4
a
to supply pure water of a predetermined temperature at a predetermined flow rate into the chamber
1
. The chemical liquid is supplied from a chemical liquid supply unit
4
b
to the line
4
a
, so that the chemical liquid can be supplied into the chamber
1
simultaneously with pure water.
In this cleaning apparatus, pure water contained in the chamber
1
needs to be replaced with the chemical liquid to immerse the workpiece
2
in the chemical liquid. The chemical liquid contained in the chamber
1
needs to be replaced with pure water for water rinsing after the workpiece
2
has been immersed in the chemical liquid. The process of replacing pure water with the chemical liquid and the process of replacing the chemical liquid with pure water take much time. In particular, the water rinsing process subsequent to the dipping process of immersing the workpiece in the chemical liquid takes considerable time to restore the resistivity of the rinsing water, which reduces processing efficiency (throughput) of the process.
A conventional single-tank spray type cleaning apparatus will be described with reference to FIG.
8
. In this single-tank spray type cleaning apparatus, a workpiece
2
is held by guide members
3
and is turned, and a nozzle
4
sprays a cleaning liquid
5
on the workpiece
2
for cleaning. This single-tank spray type cleaning apparatus, as compared with the single-tank dip type cleaning apparatus, can easily be changed from a chemical cleaning process to a water rinsing process, and hence the throughput of the single-tank spray type cleaning apparatus is higher than that of the single-tank dip type cleaning apparatus. However, when the workpiece is rotated to spin-dry the same after the last rinsing process, water marks, i.e., stains, are formed on the surfaces of the workpiece. Water marks formed on the workpiece affect adversely to the characteristics of a device fabricated by processing the workpiece, and reduce the yield of the device production system remarkably. Thus, formation of water marks on the workpiece is a problem in the spray type cleaning apparatus.
There has been no single-tank cleaning apparatus provided with a single tank in which a plurality of chemical liquids are used for cleaning, and capable of cleaning workpieces at a high throughput and of cleaning the workpieces without forming water marks thereon.
As mentioned above, the conventional semiconductor workpiece cleaning apparatuses require much time for cleaning, and are inefficient, and form water marks on the workpieces during drying after cleaning.
SUMMARY OF THE INVENTION
Accordingly, the objects of the present invention are to solve the above problems, and to provide a semiconductor workpiece cleaning method and apparatus capable of efficiently cleaning semiconductor workpieces, and of preventing the formation of water marks on the semiconductor workpieces.
According to one aspect of the present invention, a semiconductor workpiece cleaning apparatus comprises a cleaning means of a semiconductor workpiece by use of chemical liquid or pure water, charging means of drying liquid, and discharging means of the cleaning liquid. The cleaning means cleans the workpiece by spraying processing chemical liquid and/or pure water in a chamber, and/or by immersing the workpiece in the processing chemical liquid and/or pure water. The charging means takes in drying chemical liquid or vapour into contact with the processing chemical liquid or pure water in which the semiconductor workpiece is immersed. The discharging means discharges the processing chemical liquid or pure water interfaced by the processing chemical liquid or pure water.
In another aspect of the present invention, in the semiconductor workpiece cleaning apparatus, the processing chemical liquid and/or pure water is sprayed to clean the semiconductor workpiece, and then other processing chemical liquid is supplied into the chamber to immerse the semiconductor workpiece.
In another aspect of the present invention, in the semiconductor workpiece cleaning apparatus, the processing chemical liquid or pure water is supplied into and discharged from the chamber through a lower part of the chamber.
In another aspect of the present invention, in the semiconductor workpiece cleaning apparatus, the semiconductor workpiece is inverted when the lower half of the semiconductor workpiece is immersed in the processing chemical liquid while the processing chemical liquid is being supplied into the chamber. Then, the processing chemical liquid is further supplied into the chamber.
In another aspect of the present invention, in the semiconductor workpiece cleaning apparatus, the drying chemical liquid is supplied through an upper part of the chamber, and the drying chemical liquid forms a boundary layer which separates an upper gas phase from a lower liquid phase when the drying chemical liquid comes into contact with or dissolves in the processing chemical liquid or pure water.
In another aspect of the present invention, in the semiconductor workpiece cleaning apparatus, the drying chemical vapor is supplied through an upper part of the chamber so that the drying chemical vapor dissolves or condenses in a surface layer of the processing chemical liquid or pure water to form a blocking boundary layer in the processing chemical liquid or pure water. Preferably, the thickness of the blocking boundary layer is greater than the wave height of surface waves of the processing chemical liquid or the pure water. Further, preferably the thickness of the blocking boundary layer is 2 mm or more.
In another aspect of the present invention, in the semiconductor workpiece cleaning apparatus, the drying chemical liquid is supplied into the chamber through a lower part of the chamber to replace the processing chemical liquid or pure water in which the semiconductor workpiece is immersed with the drying chemical liquid.
In another aspect of the present invention, in the semiconductor workpiece cleaning apparatus, the processing chemical liquid is selected from a group of mixed liquid prepared by mixing ammonia, hydrogen peroxide and water; hydrochloric acid, hydrogen peroxide and water; sulfuric acid, hydrogen peroxide and water; hydrofluoric acid and water; hydrofluoric acid, hydrogen peroxide and water; hydrofluoric acid, ammonium fluoride and water (buffered hydrofluoric acid); or ozone and water; or electrolytic ionic water.
In another aspect of the present invention, in the semiconductor workpiece cleaning apparatus, the processing chemical liquid is selected from a group of mixed liqui
Ban Cozy
Konishi Toko
Coe Philip R.
Mitsubishi Denki & Kabushiki Kaisha
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
LandOfFree
Semiconductor workpiece cleaning method and apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Semiconductor workpiece cleaning method and apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiconductor workpiece cleaning method and apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2567865