Plasma etcher

One way to fabricate such a reactor is by deep reactive ion etching (DRIE) with a time-multiplexed inductively coupled plasma etcher (most details on fabrication are given in [77]) [7, 77, 78]. Regions of major importance such as the retainers are etched through to avoid differences in stmctural depth which may cause uneven flow. To generate various channel depths in one design, both front-side and back-... 

Figure 3. Potential distribution in a parallel plate plasma etcher with grounded surface area larger than powered electrode area, (Reproduced with permission from Ref 12 J...

Fig. 1 Prototype single wafer parallel plate plasma etcher.

The models for a plasma etcher are usually onedimensional (direction perpendicular to the electrodes in parallel plate geometry), use mobility limited description of the velocity field, use one energy equation that only involves the electron temperature, and write the electric potential in terms of Poisson s... 

Fortunately, many improvements in plasma etcher designs and plasma etching applications can and are done through experimentation and development. This approach proceeds in concert with improvements in modeling and leads to the next generation designs for plasma etchers. Some fundamental considerations for plasma etcher performance are taken up in the next section. 

Plasma diagnostics consists of tools that can be used to characterize the plasma and thus provide information on the processes that are occurring with the plasma etcher. The main tools employed are spectroscopy, emission spectroscopy, mass spectrometry, and plasma probes. A detailed discussion on how each tool works is beyond the scope of this review. However, these tools are used to identify the species present in the plasma etcher, determine the temperature of the species, and determine the electron density. 

For e-beam exposure, the resist films were spin coated on Si02 (2000 Angstroms), prebaked and exposed at 20 kV in a Cambridge e-beam microfabricator. For our initial studies, an IPC 4005 barrel plasma etcher was used to develop the resist patterns. In our recent studies, a Plasma-Therm PK-1250 planar plasma etcher was used to develop the resist patterns. 

In plasma etchers, specific radicals are selected from the mix of the species generated within the chamber to effect the etching action. For the specific case of species generated from CF4 gas within a plasma chamber, for example, the fluorine radical (F) is selected by means of an appropriately configured perforated aluminum shield or other contraption that blocks the other species from reaching the wafer. In this way, etching of the wafer proceeds only by the reaction of the fluorine radical. Substrates such as silicon, silicon dioxide, and silicon nitride are readily etched by this technique. ... 

Following the phosphorus ion implantation, the resist layer is stripped off in an oxygen-plasma etcher, and subsequently cleaned hy a wet chemical process to remove residual resists and polymers created hy the plasma process. The silicon dioxide on the wafer surface is also removed during this step. 

For certain applications a highly porous free-surface might be of importance, thus the possibility to etch the semiporous layer using a plasma etcher (Diener MRC 100) was tested. Figure7.5b,c show the successful results obtained after a 10 and 20s air plasma treatment ignited at a pressure of 0.4mbar and with the generator power set to 20 %. 

Ayon A, Braff R, Lin CC, Sawin HH, Schmidt MA (1999) Characterization of a time multiplexed inductively coupled plasma etcher. J Electrochem Soc 146(1 ) 339-349... 

As mentioned above, the spm is mostly limited to sampling the near-sinface region of a polymer system. A new technique based on tmafm has been developed to enable volume imaging with the spm. This study tracked a series of height and phase images of a styrene-butadiene-styrene (SBS) triblock polymer microdomain as the surface was being removed 7.5 nm at a time with a plasma etcher. These data are illustrated in Figure 10 (65). 

Reactive ion etching experiments were carried out in a plasma etcher P300 (Plasma Electronics). The power was set at 100 W. The pressme inside the etching chamber and the etching time were varied. The samples for plasma etching were prepared by spin coating of the micelle solution onto cleaned Si substrates. 

Various parent compounds, operating characteristics, and plasma etchers are used in etching operations. This results in diverse concentrations and compounds in the breathing zone of the maintenance technician. Currently no procedure exists to determine what reaction products will form in a particular plasma etcher. Information from past plasma etcher surveys can be used to partially determine a sampling strategy for a particular etch system. However, to a certain extent, each different system must be approached as an unknown. Therefore, two separate surveys are usually necessary to evaluate a plasma etcher maintenance operation. 

Radiofrequeney (RF)/mierowave radiation is a potential hazard that does not have good warning properties. Therefore, baseline data should be obtained for all routine operations with a potential for RF/mierowave radiation exposure above applieable standards, and baseline RF surveys of new equipment may be required. As a practical matter, a lower frequeney limit needs to be drawn to assess when baseline surveys are neeessary. Since the body is fairly transparent to RF frequencies in the kilohertz region, and standard RF/mierowave radiation meters have a lower limit of 300 or 500 kHz (depending on the meter), 500 kHz is sometimes used as a cutoff for the lower limit for thermal effeets. Most RF/microwave equipment used in semiconductor manufacturing operate at or above a frequency of 13.56 MHz. This equipment includes plasma etchers and ashers, sputtering units, mold pre-heaters, microwave ovens, and plasma enhanced CVD units. 

Etching Plasma Etching Plasma Etcher Maint. RF Radiation RF Radiation >4.9mW/cm2 12.9mW/cm2 [19][20] [17][18]... 

A plasma etcher has a number of MVs that can be adjusted in order to achieve the desired chip geometry. By applying Guidelines 6 and 8, several input variables can be selected from the four possible MVs etch time. 

A plasma etcher has a yield of good chips that is influ-... 

Plasma etchers and strippers typically use more aggressive reactant gases such as chlorine or fluorine and are constructed to withstand corrosion and pump the particulates that are often formed in the etching and stripping process. 

Plasma etcher (semiconductor processing) A vapor etching system that uses a plasma to... 

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