Coating apparatus – Gas or vapor deposition – With treating means
Reexamination Certificate
1998-10-30
2001-03-13
Jones, Deborah (Department: 1775)
Coating apparatus
Gas or vapor deposition
With treating means
C239S008000, C239S010000, C239S338000, C239S339000, C118S715000, C118S722000
Reexamination Certificate
active
06200387
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and system is invented for substrates chemical treatment and more particularly for semiconductor wafers and flat panel displays (FPD) wet processing.
2. Description of the Prior Art
Methods and systems are invented for substrates and more particularly for semiconductor wafers and flat panel displays (FPD) chemical treatment using nebulized chemicals created and carried by heated chemical gases. A nebulizer and a process chamber with novel invented design features have been provided in the prior art that are adapted to be used. Even though these innovations may be suitable for the specific individual purposes to which they address, they would not be suitable for the purposes of the present invention as heretofore described.
SUMMARY OF THE INVENTION
This method and system is invented for substrates chemical treatment and more particularly for semiconductor wafers and flat panel displays (FPD) wet processing.
The wet chemical process has been key semiconductor processing technologies since the beginning of these products fabrication. It serves both to remove micro metal and none metal contaminants introduced by any previous processing steps and to prepare an optimum surface for the next processing step. It accounts for more than thirty percent (30%) of the total VLSI (very larger scale integrated circuit) manufacturing steps. Improper wet processing can cause substrate surface damage, circuit failure, huge process chemicals and deionized water usage, which negatively effect the product yield.
The most popular wet processing chemical is still the hydrogen peroxide (H
2
O
2
) based RCA Standard Clean which consists of SC-1 (ammonium hydroxide NH
4
OH/hydrogen peroxide H
2
O
2
/DI water H
2
O mixture) and SC-2 (hydrochloric acid HCL/hydrogen peroxide H
2
O
2
/DI water H
2
O mixture) clean. SC-1 is used for light organic particle removal and SC-2 is used for metal particle removal. Other popular wet processing chemicals are SPM (sulfuric acid H
2
SO
4
/hydrogen peroxide H
2
O
2
) and SOM (sulfuric acid H
2
SO
4
/ozone gas O
2
) clean. Both SPM and SOM are mainly used to remove heavy organic contaminants. Other modified and alternative processing chemicals are being proposed and used. For examples, people use liquid hydrogen peroxide (H
2
O
2
) added liquid hydrofluoric (HF) to prevent copper adhesion to the silicon surface. Ozonated water (O
2
—H
2
O) to replace the SPM or SOM clean, etc.
Currently available prevalent wet processing method and equipment include bench processing (using different liquid chemical baths), single vessel processing (different liquid chemicals passing through the vessel), and centrifugal spray processing (different liquid chemicals spraying to substrates in a rotating chamber).
In the wet bench processing, wafers or FPD are processed and moved through a series of different liquid process chemical and rinse DI water bathes. Its main shortage is using most complicated automation controls, chemical pH value and filtration control. It also consumes most chemicals, rinse DI water and bigger footprint compare to other processing technologies. In the single vessel wet processing, wafers or FPD stay in a processing vessel (or bath) and different liquid process chemicals and rinse DI water sequentially flow through the vessel. It has smaller footprint, but it still uses considerable chemicals and rinse DI water (even less compare to the wet bench). In the centrifugal spray processing, wafers or FPD are rotating in a processing chamber while process liquid chemicals and rinse DI water sequentially spray onto the substrates. It also has smaller footprint but it uses more complicated chamber rotating mechanism and control.
Other wet processing technologies are also used in semiconductor wafer and flat panel displays (FPD) clean process, for example, very higher pressure (2000-3000 psig) liquid process chemical and rinse DI water jet clean, hydrophilic fiber scrubbing clean, etc. They are mainly used for post CMP (chemical mechanical polish) clean for wafers and single substrate processing for FPD. The shortage of higher pressure liquid jet clean is to generate higher stress inside the substrates, and the scrubbing clean could scratch the surface of the substrates.
As semiconductor wafer and flat panel display (FPD) keeps shifting toward larger sizes, companies, scientists and engineers in these industries become more concerned to the Cost Of Ownership (COO) to the processing equipment and technologies. In other words, they are more care of the process dollar cost per substrate (wafer or FPD). In the wet processing area, the rinse DI water and liquid chemical cost counts the most percentage in any cost of ownership (COO) analysis. Cordon D. Ching and Robert B. Murtha from Intel disclosed in their COO study paper that DI water is the highest cost (32%) and liquid chemicals is the third cost (16%) in an entire 200 mm diameter wafer wet process. The capital equipment cost is the second (23%). Reducing DI water and chemical consumption would be a tremendous benefit not only to the cost of ownership (COO), but also to the more heightened environment these days.
People have been looking for new process methods and technologies to reduce the COO without compromising the importance of minimizing contamination, increasing uniformity and throughput. The dry (vapor or gas) cleaning which use much more less chemicals was proposed and developed to replace certain wet processes (wet processes has been largely replaced by plasma etching) as the permissible concentrations of contaminants scale down with the increasing density of IC (integrated circuit). But such clean processes can only remove specific types of contaminants, but also leave some particles and metallic contaminants from the dry process. They may also cause some substrates surface damages with ultraviolet excited or plasma-assisted dry cleaning. The dry cleaning process doesn't have certain particle removal results which wet process cleaning phase, since it can not use certain well developed cleaning chemical mixtures since they do not exist in their vapor or gas phase (for example SC-1, NH
2
OH+H
2
O
2
+H
2
O) mixtures). Thus, the wet chemical processing technologies will continue to be the dominant technologies for years to come in the industries.
Accordingly there is a need for a new method and system which will satisfy the continuing improvements in performance and cost effectiveness both in the wet process technologies and equipment designs. The present invention can meet the need. The main object of the invention is to design a new wet process method and system with minimum chemical and DI water consumption, minimum waste chemical disposal, and simple equipment structure.
The method and system would also be used for numerous processes in the substrates (wafer and FPD) fabrication, like nebulized chemical deposition (NCD), nebulized photo resistor coating (NPC), nebulized chemical platting (NCP), etc.
According to the embodiment of the present invention, a method and system for treating substrates is provided. It uses nebulized chemicals created and carried by heated chemical gases to treat the substrates.
The substrates to be processed will be loaded into the carrier section of the process chamber by a robot (it is preferred to use the robot, but they can also be loaded manually, or semi-automatically). The loaded chamber carrier section will be transferred by automation into the system. Then the lid and bottom section of the process chamber will be sealed together with the carried section by a mechanical structure.
Based on each process requirement, an inert gas said nitrogen (N
2
) with preset temperature control flow into the process chamber first for the substrate temperature conditioning, then different heated and pressurized nebulized chemicals are bringing into the process chamber and circulating inside. The micro nebulized chemicals would penetrate the intricate topologies on the substrates with he
Jones Deborah
Miranda Lymarie
St Landau Norman
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