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Wafer Recovery
Reclaimed Wafers
Noel Technologies, Inc. offers full wafer recovery extending the life of wafers as well as offering a cost effective solution to customers. Reclaimed wafers may be made from prime wafers which have been stripped of photo resist, oxide, poly, nitride and metals. They are mechanically repolished to remove film, surface scratches and residual patterns. After polishing, wafers are cleaned and batch sorted for thickness, bow/warp/flatness and resistivity. Thin film may then be applied to complete the process. The number of times a wafer may be reclaimed is limited, as the process physically reduces the thickness of the substrate. Eventually, test wafers become damaged, too deeply scratched or too thin to be reclaimed.
 Recycled Test Wafers
The wafer recycling process involves a wet chemical etch that will remove many thin films. The process is non-mechanical. No substrate material is removed and surface flatness characteristics are not changed. Unlike wafer reclamation, this process is ineffective for removing scratches or haze. Wafers may be recycled with the proviso that they meet particular incoming specifications. Generally, for successful recycling, wafers must be free of scratches greater than a total of 3cm in length. Haze, ghost patterns and pitting must be minimal. Wafers with cracks, chips or warping cannot be recycled successfully. One of the major benefits of wafer recycling is the repeatability of the process. Wafers processed by Noel may be routinely recycled ten times or more. If recycled wafers become scratched or slightly damaged, they are flagged and may then be reclaimed. The cost-saving implications as well as the environmental benefits of this strategy is beneficial to our customers.
Incoming Inspection
Upon receipt of material, Noel visually inspects wafers for chips and cracks. Wafers with these types of defects will be rejected and returned unprocessed. Noel does not offer particle specs, or surface guarantees on recycled material. Noel is not responsible for wafers broken in process.
| Defects |
Reject |
Accept |
| Finger Prints |
0% |
100% |
| Chips/Cracks |
100% |
0% |
| Water Spots/Slurry |
0% |
100% |
| Haze |
Customer Spec |
Customer Spec |
| Scratches |
Customer Spec |
Customer Spec |
Modifications to Noel’s Standard Specifications must be submitted in writing, prior to acceptance of order. Proprietary information - Not to be disclosed to any third party.
Thin Film Deposition, Wafer Recycling and Wafer Processing
Noel Technologies, Inc. provides specialized wafer foundry services and products. Combining time-proven expertise in the area of thin film deposition, wafer recover and particle measuring services, Noel delivers quality silicon wafers that meet or surpass customer expectations.
Noel Technologies has doubled wafer volume nearly every year since, and delivers high volume, 300mm wafer processing services, such as thermal oxide processing, wafer cleaning processes and wafer recycling services. The company has a normal operating capacity of 5,000 wafers processed per day.
Wafer Recovery/Wafer Recycling
RReclaimed wafers can be created from silicon wafers stripped of photo resist, oxide, poly, nitride and metals. They are mechanically re-polished to remove film, surface scratches and residual patterns. After polishing, wafers are cleaned and sorted for thickness, bow/warp/flatness and resistance. Thin film may then be applied to complete the process.
Noel’s proprietary process removes very little silicon, which allows multiple reclaims or recovery. Other types of reclaim processes take off more silicon than Noel’s proprietary chemical process.
Wafer recycling involves a wet chemical etch for thin film removal. Wafers must meet particular specifications if they are to be successfully recycled, e.g. they must be free of scratches exceeding a total length of 3cm. Haze, ghost patterns and pitting must be minimal. Wafers with cracks, chips or warping cannot be recycled successfully.
Wafers processed by Noel can be regularly reclaimed up to ten times. If recycled wafers become scratched or slightly damaged, they are flagged and may then be reclaimed. The cost-saving implications as well as the environmental benefits of this strategy are obvious.
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| WAFER RECOVERY PROCESS |
4/5” |
6” |
8” |
12” |
Oxide/RESIST Strip (up to 20k)1 with Film Deposition
(price does not include film charge – RCA/SRD Clean)12 |
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Oxide/RESIST Strip (up to 20k)1
with RCA/SRD Clean |
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Oxide/RESIST Strip (up to 20k)
with RCA/RPC™ Clean |
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Wafer Recovering with Film Deposition
(Price does not include film charge – RCA/SRD Clean)12
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Wafer Recovering (Strip Metals, Patterns, Poly, Oxide, Other films)
with RCA/SRD Clean12 |
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Wafer Recovering (Strip Metals, Patterns, Poly, Oxide, Other films)
with RCA/rpc™ Clean2 |
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| Copper Recovery with RCA/RPC™/SCROD Clean3 |
N/A |
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Kiss Polish with Film Strip
Minimum removal (~1-2 microns) |
N/A |
N/A |
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Kiss Polish
Minimum removal (~1-2 microns) |
N/A |
N/A |
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| No Particle Guarantees |
1Clean box = 5” = $3.50 – 6” = $4.00 – 8” = $8.00 – 12” = $35.00. Please add RPC™ (Reduced Particle Clean) for particle sensitive material.
2Multi-Layers = $5.00/Layer. Prior to pickup, noel must be notified of wafers with photo resist.
Non-compliance may result in an additional charge of $250.00 for bath/filter change.
3Spin-cleaning with repetitive use of ionized water and dilute hf.
| WAFER CLEANING |
4/5” |
6” |
8” |
12” |
| RCA/SRD Clean |
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| RCA/SCRUB |
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| RCA/RPC™ (Reduced Particle Clean) |
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| No Particle Guarantees |
| OTHER SERVICES |
4/5” |
6” |
8” |
12” |
Surfscan Service - Bin Counts
Setup Charge $250.00 – additional $1.50 per wafer charge for maps |
N/A |
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N/A |
Film Mapping
Polar Scans, 49-Point Measurements, etc. |
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Bow/Warp Measurements (TTV, TIR)
Minimum Charge $250.00 |
N/A |
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N/A |
Engineering Time
Special Cleans, Chemicals, and Gases will be billed separately |
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Thin Film/Thermal Oxide Deposition on Test Wafers and Monitor Wafers
A cost-effective alternative to prime wafers, test wafers are used for particle monitors, oxide growth monitors, etch rate monitors, implant dosing and for characterizing new and existing equipment and processes. Test and monitor wafers may be used in very high-level work where the use of prime wafers is limited for final evaluation.
Thermal oxide, with a 2% to 4% uniformity variation, can be frown quite easily on test wafers. Other deposited/sputtered thin films may be applied to these wafers as well. Test wafers with low TTV (Total Thickness Variation) are ideal for photolithography.
Prime Wafer Reclaim Processes
Noel Technologies delivers exceptional quality reclaimed prime wafers in 4", 5", 6", 8", and 12" sizes. These wafers meet all SEMI (Semiconductor Equipment and Materials International) specifications for these materials.
Typical reclaim wafer applications include:
- Particle monitors
- Thin film thickness measurements
- Etch rate monitors
- Equipment characterization
- Furnace barrier
High quality reclaim wafers will be used by device manufacturers and equipment suppliers. Noel Technologies routinely monitors metal contamination and trace metals in the low E10 atoms/Cm2.
Thin Film/Reclaimed Wafer Particle Measurement Services
Noel Technologies can provide customers with very tight particle specifications for thin films and reclaimed wafers, utilizing a Tencor particle-measuring tool. We accept full responsibility for the quality of a customer’s reclamation process and customized thin film.
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