Passive Aerosol Dryer^TM PAD-45
45 nm Clean Drying Process
50mm to 450mm Wafers &
Larger Substrates

Applications OEM Kits For Chamber or Bench Integration FEOL/BEOL High Aspect Ratio/Deep Trench Drying MEMS and other Sensitive Devices/Substrates Hydrophopic Surfaces Features/Benefits 45 nm Particle Neutral Drying High Reliability and Low COO Consistent and Repeatable Results Proprietary Venturi Aerosol MakerTM Patent-Pending Passive Aerosol Drying Super-Efficient IPA Usage @ I-6 ml Per Cycle IPA Liquid Diffusion TechnologyTM Watermark Free Environmentally Friendly, US-EPA Effluent Compliant Always CleanTM Proprietary IPA Filtration & Dispense

Liquid Diffusion Technology

ChemAcoustic's LIQUID DIFFUSION TECHNOLOGY (LDT) provides enhanced drying performance for a variety of substrates and material sufaces. This proprietary drying process and its subsystems control the creation of an ultra-pure IPA aerosol layer that moves across a substrate to diffusively remove water, without leaving watermarks.

The VENTURI AEROSOL MAKER and its subsystem very efficiently creates the ultra-pure IPA aerosol layer with the robust process flexibility necessary to dry high aspect ratio/deep trench topography, half-pitch wafer spacing, and a wide variety of other applications. This subsystem uses no energy to passively create a unique range of IPA aerosols that other aerosol dryers simply cannot create. Furthermore, using an IPA aerosol in itself eliminates the safety hazard of IPA vapor dryers.

The ALWAYS CLEAN subsystem moniters the filtration and level of IPA to insure that the IPA delivery path is always wet and the filter pressure is nominal. This eliminates the inconsistent performance of other aerosol dryers using a sonic head that dries out every cycle and then "self cleans" into the process bath

The EZ-FRONT FILL subsystem is a combination of a front panel fill and IPA reservoir. This system enables non-intrusive, quick and easy IPA fills without removing panels or replacing storage bottles.

ChemAcoustic's PASSIVE AEROSOL DRYERS use all of the aforementioned proprietary subsystems to provide an efficient and clean drying system that is safe and environmentally friendly.

Typical Process Sequence

IMMERSION PROCESS -
1) Wafer process cassette is loaded into a DIW filled/unfilled ultraclean N2 purged tank.
2) DIW rinse for time or resistivity.
3) VENTURI AEROSOL MAKER creates IPA aerosol layer on DIW surface.
4) Controlled drain of DIW/IPA layer from tank dries using LDT.
5) Temperature and flow controlled N2 assures complete drying.
6)Clean, dry wafers unloaded. Typical drying process time after immersion and rinse is 6-10 mins. per batch.

SINGLE WAFER PROCESS - A horizontally positioned wafer is rotated at low speed while ultraclean DIW and IPA aerosol from the VENTURI AEROSOL MAKER are dispensed onto the DIW surface to dry the wafer using LDT. Typical drying process time is 15-30 seconds per 300-450mm wafer.

The Passive Aerosol Dryer (PAD-45) dries with a particle neutral performance or better at 45 nm that is watermark free. These particle performance results were obtained and tested for particle performance at a customer?s site while running actual CMP application processes. The PAD-45 dryer was integrated as a kit into an OEM single wafer process chamber running 300mm wafers for these tests. The PAD-45 dryer also dries 450mm wafers with comparable performance results.