An Ultradilute to Near Zero Ammonia Process for Removing Particle and Metal Ions

Technology Highlights

A new process has been developed as an alternative to the traditional SC-1 or SC-2 cleaning process. In contrast to the present cleaning processes, the new process does not rely on surface etching to remove particles. Particle detachment occurs primarily by using megasonic energy and by creating “clusters.”

This new process essentially requires no chemicals, except for DI water, ammonia gas, and nitrogen. The new process is very efficient at removing particles and metal ion contamination--without changing the surface roughness.


As the semiconductor industry develops processes for narrow nodes, the following key challenges emerge in cleaning wafers--for both Front End Operation Line (FEOL) And Back End Operation Line (BEOL):

  • Fragile device structures and materials
  • Stringent requirements for cleanliness and loss of material

What Is the Problem?

Current “etching” cleaning methods cause pattern damage and excessive material loss—and are not environment friendly.

What Is the Solution Developed by Nano Green Technology, Inc?

Nano Green Technology, Inc. has developed the following breakthrough innovative wafer-cleaning paradigm for wafer wet processing:

  • Uses a “charged solution” of NH3 to form clusters that attract particles at the molecular level--as particle “scavengers.”
  • Establishes a radical new approach to ultra dilute wafer cleaning.
  • Cleans the surface of the wafer, in the most “green” environmentally friendly way.
  • The charged solution can be used for wafers cleaning--at any point in the fab--where DI water is used as a solvent.
  • Combines the most critical features of any chemical cleaning technology on the market. Features include the following:
    • A simple, easy-to-use gas injection system that uses familiar and available gas and Megasonic devices.
    • Environmentally “green” technology that uses extremely dilute (next to zero) chemistry, so that waste treatment, bulk deliveries, or Voc measurements are not required.
    • You can use Nano Green’s “charged solution” for Single Wafer Processing (SWP), which requires a fast surface treatment in either a vertical or horizontal position.

Technology Introduction

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