Tegal 901e Tegal 903e Plasma Etch Equipment

Posted on 1/23/2013
8024 days to go

by Peter Chen (peterchen@allwin21.com) in CA,United States 


sales@allwin21.com

http://www.allwin21.com/tegal-plasma-etcher.asp


Allwin21 Corp. focuses on and professionally provides the following fully refurbished and customized Tegal 900 (Tegal 9XX) Plasma Etcher/Etching/Descum equipment with highQuality,rightCost,quick Delivery and excelentService for Semiconductor industry,MEMS, Biomedical, Nanotechnology,Solar,LEDs etc.

Tegal 901e | Tegal 903e |Tegal 901e TTW | Tegal 903e TTW


The TEGAL 9XX Plasma/RlE Etch Systems are used by the Semiconductor Industry for integrated circuit fabrication. The systems are used in one part of the sequence of manufacturing steps that transfer a pattern formed from a layer of photosensitive material, the photoresist, to a layer that makes up a permanent part of the finished device. The process of defining a pattern with photoresist is known as photolithography, while the etch process transfers the photoresist pattern to the permanent layer.

The materials used in semiconductor device fabrication may be etched in two ways, either wet or dry. In wet etching, the material to be etched comes into contact with a liquid, in which the material dissolves. The action of the liquid solvent removes material that is exposed to the solution. Material that is masked, or covered, by the photoresist remains after etching as a permanent pattern. Dry etching, also termed plasma etching, substitutes a reactive gas mixture for the liquid solvent to accomplish the same result, that of pattern transference. Dry etching is capable of transferring smaller features into the permanent layer than wet etching, with greater control over the variation in feature size. The current
requirements of the Semiconductor Industry necessitate the use of dry etching for most of the pattern-transfer steps. As semiconductor devices become denser and faster, the shift to dry etching will continue.
Dry etching systems are divided into two broad categories: batch etchers and single-wafer etchers. Batch etching systems etch more than one wafer at a time, while single-wafer systems process just one wafer to completion before proceeding to the next.

The TEGAL 9XX Plasma/RlE Systems are dry, single-wafer etchers. Wafers in the 9XX are transported to a Reaction Chamber. A gas mixture is introduced into the Reaction Chamber, and the gas mixture is caused to become reactive by the application of radio frequency (RF) electromagnetic radiation. The reactive mixture, or plasma, etches away material that is not covered by the masking photoresist. The etch process is terminated at an appropriate time, the wafer is unloaded from the Reaction Chamber, and a new wafer is introduced. The cycle repeats. The general mechanisms by which etching proceeds in a plasma etching system are as follows: RF power accelerates free electrons in a low-pressure gas mixture. The accelerated electrons undergo collisions with gas molecules and these collisions result in the generation of several new species. If the gas molecules are broken apart, or dissociated, free radicals are formed. Free radicals are
chemically reactive molecule fragments with no net electrical charge. Radicals that come into contact with material on the wafer surface may be sufficiently reactive chemically to combine with the surface to form volatile reaction products. The gas molecules may be dissociated and ionized. If they are, the molecule fragments have a net electrical charge and respond to electrical fields present in the reactor. Ions accelerated to the wafer surface may provide sufficient energy to activate chemical reactions between the surface and gas radicals or the surface and neutral gas species. This results in etching of the surface material. Finally, gas molecules may capture energy from the accelerated electrons and release the
captured energy as a photon, or light. This last process accounts for the glow that is characteristic of plasmas.
The TEGAL 9XX System Plasma/RlE etchers have been configured to take advantage of the characteristics of plasmas for etching various films. Each of the models in the 9XX family has been optimized for specific etches of specific films. All models have the common ability to implement multistep etch recipes using multiple process gases. An optical monitoring system provides a means for determining etch completion so the etch process can be terminated.
The 9XX plasma etch process chamber is a capacitively-coupled diode operated in the RIE mode. The lower electrode is powered by 13.56 MHz RF energy and incorporates a grounded upper electrode. The simple fixed-gap design ensures repeatable process results and offers simplified cleaning and preventive maintenance. The fixed-gap electrode spacing is available in two configurations: a 6mm or 38mm gap between upper and lower electrodes.

The 6mm-gap reactor (9x3) confines the plasma very closely between the electrodes, providing the plasma potentials and ion densities necessary to break oxide bonds at reasonable rates. This configuration is optimum for etching silicon dioxide and other dielectric materials. Typical etchants used are CHF3, CF4, SF6, and He.

The 38mm-gap reactor (9X1) causes the reactive ions to travel further, so the plasma expands, spreading the energy throughout the full volume of the reactor and decreasing the plasma potential. Etching in the 38mm-gap reactor, compared
to the 6mm-gap reactor, is accomplished more by the chemistries involved. The 38mm-gap reactor is typically operated with SF6 or CF4/O2 etch gases. It is cleaner and minimizes plasma-induced damage. This configuration is ideal
for isotropic, polysilicon, and silicon nitride applications, as it is inherently selective to oxide.

Although these configurations are optimized for specific films, most etch applications can be successfully performed in either of the chamber configurations. The application mix and specific production requirements dictate which chamber is used.

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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.

Reactive-ion etching (RIE) is an etching technology used in microfabrication. It uses chemically reactive plasma to remove material deposited on wafers. The plasma is generated under low pressure (vacuum) by an electromagnetic field. High-energy ions from the plasma attack the wafer surface and react with it.

An inductively coupled plasma (ICP) is a type of plasma source in which the energy is supplied by electric currents which are produced by electromagnetic induction, that is, by time-varying magnetic fields.

Allwin21 Corp. professionally provides the following plasma Etch/RIE/ICP semionductor equipment with high Quality,right Cost,quick Delivery and excelent Service.

Tegal 901e | Tegal 903e |Tegal 901e TTW | Tegal 903e TTW | Lam Rainbow 4420/4428 | Lam Rainbow 4520/4528 | Lam Rainbow 4620/4628 |


Lam Rainbow 4720/4728 | Lam AutoEtch 490 | Lam AutoEtch 590 | Lam AutoEtch 690 | Lam AutoEtch 790 | Matrix 303 | Gasonics AE 2001 | STS Multiplex I