A quick dump rinse (QDR) tank provides fast rinse operation for semiconductor wafers and other parts while conserving ultrapure or deionized (DI) water. Also called a DI rinse tank, a quick dump rinse tank helps prevent over-processing of semiconductors in wet chemical process equipment.
Cleaning, etching and stripping applications for semiconductor wafers often use potent chemicals such as potassium hydroxide (KOH) and hydrogen fluoride (HF). These and other chemical residues must be completely removed, including in blind holes and pockets, to ensure that chemicals do not continue to process (etch, strip, etc.). Continued chemical processing after removal from wet process equipment can result in over-etching, stripping, failed wafer patterns and other semiconductor failures.
How a Quick Dump Tank Works
The quick dump rinser fills deionized (DI) or ultrapure water from the bottom of the bath through nozzle manifold ports that direct the flow upward and around the wafer part surface. The upward spray-under immersion removes particles and chemicals from the part. The top of the tank has an overflow weir to discard the removed particulate and chemistry.
When overflow is complete, the bottom quick dump door opens and the rinse water drains from the tank in a matter of seconds. Meanwhile, nozzle sprayers on top of the tank keep the product wet with fresh, clean DI water during the dumping process. For high precision applications requiring extremely clean wafers, post-process high-flow cascade overflow rinse tanks provide an even higher level of chemical and particulate removal.
Quick Dump Rinse Tank
Proper rinsing using a quick dump rinse tank achieves the following functions:
- Stopping chemical reactions such as etching, stripping, etc.
- Applying clean rinse water on parts after chemical wet processes.
- Complete removal of contaminants, particulates and chemistry from wafers or parts.
DI Rinse Types for Semiconductor Manufacturing
The following three types of rinsing are typically used in semiconductor manufacturing, depending on the application:
- Cascade overflow rinsing – Wafers and parts are completely immersed in the rinse tank and a continuous overflow of fresh DI water from a bottom inlet overflows at the surface.
- Spray rinsing – An operator uses a spray wand to spray DI or ultrapure water, or a spray manifold at the top and sides of the tank sprays parts.
- Quick dump rinsing – Utilizes both spray and overflow rinsing. Water is quickly evacuated from the tank, flushing particulate and contaminants away from wafer parts.
Cascade Overflow Rinse Tanks
Features and Options of Quick Dump Rinse Tanks
- Four-sided cascading overflow weir helps break surface tension and removes particles from the process area.
- Minimal welds, corners, and sloped edges to prevent particle entrapment on tank surfaces.
- Nitrogen N2 agitation bubbler
- Materials of Construction (application dependent): Polypropylene, Stainless Steel, PVDF, Teflon PTFE / PFA, PVC
- Resistivity monitoring for water quality and to ensure that semiconductor wafers, cassettes, and parts are properly rinsed.
- DI water reclamation, recycling and reuse
- Flowmeter for volumetric control
- Hot DI Water compatible
- Standalone tank, or build into full wet bench process line
- A touch-screen PLC allows part-specific rinsing programs controlling the number of rinse, high-flow cascade and dump cycles.
Cascade Overflow Rinse – Top View
Quick Dump Rinse Tank Advantages for Wet Process Equipment
- Up to 80% reduction in DI water consumption compared to overflow rinsing alone.
- Up to 75% faster process times, by rinsing chemistry from the wafer and cassette surfaces more rapidly.
- Superior rinse performance of QDR tanks using surface spraying with less time and water.
All of our quick dump rinse tanks are sized to the customer application. Contact us to learn more about how quick dump rinse tanks can benefit your process.