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.

·Lam Autoetcher 590

·Lam AutoEtch Lam 490

·Lam Rainbow 4420 Plasma Etch

·Lam Rainbow 4428 for Plasma Etch

·Lam Rainbow 4520 Oxide Etch

·Refurbished Tegal 901e

·Refurbished Tegal 903e

·Refurbished Matrix 303

·Refurbished Matrix 403

·Refurbished Gasonics AE 2001

                                   

 Refurbished  Gasonics AE2001           Refurbished Matrix303   

 Allwin21 Corp. can also provide  Allwin21 Corp proprietary AW Control Software and Superior Temperature Control Technology  to upgrade the refurbished equipment which provides the following significant advantages

• Integrated process control system
• Real time graphics display
• Real time process data acquisition, display, and analysis
• Programmed comprehensive calibration and diagnostic functions
• Better performance and maintenance than the original systems

 TM:
Gasonics  is a Registered Trademark of Novellus Corp.
Matrix is a Registered Trademark of Matrix Integrated Systems, Inc.
Heatpulse  is a Registered Trademark of AG Associates.
Branson is a Registered Trademark of  Novellus Corp.