The Effective Free Classifieds

Manufacture:Tel

Condition:Used, good condition, complete Vintage:1994

Price:$22,500.00,­ AS IS, WHERE IS, Advanced Payment.

It is not tested or refurbished.It is sold *AS-IS WHERE IS*.Allwin21 accepts no responsibility or liability for the use

and/or functionality of the system.

Amount:1 set

No:AW-00021-01

More information: sales@allwin21.com­

Plasma Etch

Etching is used in microfabrication to chemically remove layers from the surface of a wafer during manufacturing. Etching is a critically important process module, and every wafer undergoes many etching steps before it is complete.
If the etch is intended to make a cavity in a material, the depth of the cavity may be controlled approximately using the etching time and the known etch rate. More often, though, etching must entirely remove the top layer of a multilayer structure, without damaging the underlying or masking layers. The etching system's ability to do this depends on the ratio of etch rates in the two materials (selectivity).
Some etches undercut the masking layer and form cavities with sloping sidewalls. The distance of undercutting is called bias. Etchants with large bias are called isotropic.
Modern VLSI processes avoid wet etching, and use plasma etching instead. Plasma systems can operate in several modes by adjusting the parameters of the plasma. Ordinary plasma etching operates between 0.1 and 5 Torr. (This unit of pressure, commonly used in vacuum engineering, equals approximately 133.3 pascals) The plasma produces energetic free radicals, neutrally charged, that react at the surface of the wafer. Since neutral particles attack the wafer from all angles, this process is isotropic.
The source gas for the plasma usually contains small molecules rich in chlorine or fluorine. For instance, carbon tetrachloride (CCl4) etches silicon and aluminium, and trifluoromethane etches silicon dioxide and silicon nitride. A plasma containing oxygen is used to oxidize ("ash") photoresist and facilitate its removal.

Allwin21 Corp can provide the following refurbished Etcher equipment.

Refurbished Matrix303
Refurbished Matrix403
Refurbished Gasonics AE2001
Refurbished Gasonics PEP3510
Used Lam Rainbow 4520 Oxide Etch
Used Lam 4428 for Plasma Etch

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