Unity II E 855 DD Dry

The Tokyo Electron Unity II is a modular cluster platform designed for dry etching processes in semiconductor fabrication. The system integrates multiple process chambers around a central wafer handling robot to enable sequential etch steps without breaking vacuum.

Dry etchers use a plasma discharge to generate reactive ions and radicals that chemically and physically remove material from the wafer surface. The plasma is typically created by applying radio-frequency (RF) power to a process gas mixture inside a low-pressure vacuum chamber.

In a cluster tool like the Unity II, wafers are loaded through an atmospheric interface and transferred under vacuum to one or more etch chambers. Each chamber can be tuned for a specific film type and etch profile by controlling gas composition, RF power, pressure, and temperature.

Dry etch tools are used in both front-end-of-line (FEOL) and back-end-of-line (BEOL) process steps. In FEOL, they pattern polysilicon gates and silicon trenches; in BEOL, they define metal lines and via holes in interlayer dielectrics.

The Unity II platform sits between lithography and subsequent deposition or cleaning steps. After photoresist is patterned, the etcher transfers the pattern into the underlying film, and the remaining resist is then removed by ashing or wet stripping.

Dry etchers are employed to etch a wide range of thin-film materials, including silicon dioxide, silicon nitride, polysilicon, and various metals such as aluminum and tungsten. The choice of process chemistry and hardware configuration determines the etch selectivity, profile, and uniformity.