Reduced Time for Uniform Etching of Cu Power Planes during FIB Editing

2003 ◽  
Vol 766 ◽  
Author(s):  
V.V. Makarov ◽  
W.B. Thompson ◽  
T.R. Lundquist
Keyword(s):  
Etch Rate ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Ion Bombardment ◽  
Dry Etching ◽  
Reduced Time

AbstractDry etching of Cu challenges the Focused Ion Beam (FIB) removal of metallizations. Cu metallizations are comprised of numerous, randomly orientated crystallites. Each orientation shows a different etch rate under ion bombardment, leading to unacceptable damage to underlying dielectric. An improved methodology for uniform Cu etching over dielectric consists of three steps: 1) Exposure, 2) Initial off-normal bombardment and 3) Chemistry assisted ion bombardment. Comparison is made with and without preliminary off-normal bombardment. It is shown that Cu etching preceded by off-normal bombardment was completed ∼50% sooner with decreased dielectric over-etch.

Roughness Effects During Focused Ion Beam Repair of X-Ray Masks with Polycrystalline Tungsten Absorbers

1992 ◽  
Vol 279 ◽  
Author(s):  
R. R. Kola ◽  
G. K. Celler ◽  
L R. Harriott
Keyword(s):  
Material Removal ◽  
Etch Rate ◽  
Focused Ion Beam ◽  
Removal Rate ◽  
Ion Beam ◽  
Sidewall Roughness ◽  
X Ray ◽  
Polycrystalline Tungsten ◽  
Absorber Material ◽  
Defect Repair

ABSTRACTTungsten is emerging as the absorber material of choice for x-ray masks due to recent advances in the deposition of low stress films. For a practical technology, the masks must be free from defects. These defects may be in the form of excess or missing absorber. Finely focused ion beams have been used for defect repair on x-ray masks, both for removal of excess absorber material by physical sputtering and for addition of absorber material by ion-induced deposition. The eifect of ion channeling in polycrystalline tungsten films is spatially nonuniform material removal during sputtering. Different grains will have significantly different sputtering yields, depending on their orientation with respect to the direction of the ion beam. The repaired features then suffer from roughness on the bottoms and sidewalls of the sputter craters. We have investigated the use of XeF2 assisted sputtering with a 20 keV Ga+ focused ion beam to reduce this roughness. The chemical etching component of the material removal lessens the directional dependence and therefore the roughness during defect repair. It was also found that chromium etch rate was reduced in the presence of XeF2 gas while the etch rate of W was enhanced so that the removal rate of Cr is much less than that of W. We can take advantage of this etch selectivity by using a thin Cr layer under the W absorber as an etch stop layer to eliminate the roughness at the bottom of the features and a thin layer of Cr on top of the W as an etch mask for reducing the sidewall roughness.

scholarly journals Surface Rippling & Ion Etch Yields of Diamond Using a Focused Ion Beam: With or Without Enhanced-Chemistry, Aspect Ratio Regulates Ion Etching

2006 ◽  
Vol 14 (6) ◽  
pp. 28-35 ◽  
Author(s):  
W. J. MoberlyChan ◽  
T. E. Felter ◽  
M. A. Wall
Keyword(s):  
Aspect Ratio ◽  
Surface Finish ◽  
Etch Rate ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Processing Parameters ◽  
Specimen Preparation ◽  
Surface Topographies ◽  
Target Sample ◽  
Small Parts

The Focused Ion Beam (FIB) instrument, originally designed for semiconductor circuit modification and repair, has found considerable utility as a tool for specimen preparation in several microscopy disciplines and for micromachining small parts. Essentially, a FIB makes very small and precise cuts into a target sample, which implies well-controlled etch rates and close tolerances of surface finish. However, redeposition can affect etch rate and final surface topographies. This work quantifies this redeposition as it modifies yields for different parameters of etching; models the influence of redeposition as applicable to all ion beam processing; and optimizes FIB processing parameters for enhanced yields.

Photothermally Assisted Dry Etching Of GaN

1996 ◽  
Vol 423 ◽  
Author(s):  
R. T. Leonard ◽  
S. M. Bedair
Keyword(s):  
Activation Energy ◽  
Laser Fluence ◽  
Etch Rate ◽  
Ion Beam ◽  
Sample Surface ◽  
Dry Etching ◽  
Process Conditions ◽  
Ion Damage ◽  
Arf Excimer Laser ◽  
193 Nm

AbstractPhotoassisted dry etching of GaN in HC1 by 193 nm ArF excimer laser is developed as apotential alternative process to eliminate the ion damage and surface roughness which occur inetching techniques that involve an energetic ion beam impinging the surface. A directed stream ofHC1 etchant with background pressure of ∼ 5 × 10−4 Torr, sample surface temperature between 200 to 400°C, and laser fluence of 10 to 20 mJ/ pulse combine to produce etching. The photoassistedetching reaction under these process conditions is thermal in nature, with activation energy near 1.2kcal/ mol. Increases in laser fluence results in increase of etch rate, but the surface also becomesrougher. Distinct etch features can be produced with smooth surfaces at expense of etch rate.

Si Nanostructure Fabrication by Ga+ FIB Selective Doping and Anisotropic Etching

1991 ◽  
Vol 256 ◽  
Author(s):  
A. J. Steckl ◽  
H. C. Mogul ◽  
S. Mogren
Keyword(s):  
Etch Rate ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Anisotropic Etching ◽  
Wet Etching ◽  
Fabrication Technique ◽  
Nanostructure Fabrication ◽  
Implantation Energy ◽  
Si Substrates ◽  
Si Nanostructures

ABSTRACTA novel fabrication technique involving the use of focused ion beam (FIB) selective implantation to fabricate nanostructures on crystalline Si substrates in conjunction with anisotropic etching is described. Using this maskless & resistless approach, Si nanostructures were fabricated by FIB implantation of Ga+ at doses from 1015 to 1016/cm 2. Wet etching in KOH/IPA does not attack the implanted region, while it removes the underlying Si anisotropically, with a very low etch rate on the {111} planes. The result is a cantilever-like structure whose thickness is dependent on the implantation energy and dose. Pre-etching rapid thermal annealing at 600°C for 30 sec does not prevent structure fabrication and post-etching RTA does not affect the shape of the structures.

High-Aspect-Ratio Micromachining of Fluoropolymers Using Focused Ion Beam

2007 ◽  
Vol 1020 ◽  
Author(s):  
Yoshinori Matsui ◽  
Nozomi Miyoshi ◽  
Akihiro Oshima ◽  
Shu Seki ◽  
Masakazu Washio ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Etch Rate ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Etch Rate ◽  
Etched Surface

AbstractPoly(tetrafluoroethylene) (PTFE) microstructure with high aspect ratio (> 200) and without solid debris along the edge was fabricated with high etch rate by using FIB. Gasification of PTFE by FIB is responsible for the high aspect ratio, the high etch rate, and the no solid debris. Roughness of etched surface of the PTFE increases with fluence, although edge of the etched area has good profiles. The etch mechanism seems to be complicated.

Angle of Incidence Effects in Ion Beam Processing

1988 ◽  
Vol 128 ◽  
Author(s):  
J. M. E. Harper ◽  
S. E. Hörnström ◽  
P. J. Rudeck ◽  
R. M. Bradley
Keyword(s):  
Etch Rate ◽  
Ion Beam ◽  
Etching Rate ◽  
Normal Incidence ◽  
Ion Bombardment ◽  
Angle Of Incidence ◽  
Processing Parameter ◽  
Ion Beam Etching ◽  
Characteristic Wavelength ◽  
Glancing Angle

ABSTRACTThe angle of incidence of ion bombardment is an important processing parameter, which can strongly affect the shape, composition and microstructure of bombarded surfaces. We describe several phenomena directly related to the angle of ion incidence during ion beam etching and ion beam assisted deposition. First, the development of surface ripple topography during ion beam etching is modeled. Surface perturbations are shown to grow under ion bombardment, while surface selfdiffusion acts to select a characteristic wavelength. The orientation of these characteristic ripples changes by 90° as the angle of ion incidence is varied from near-normal to near-glancing angle. The second example is the effect of angle of incidence on the etching rate of Ta under mixed Ar-O2 ion bombardment. For pure Ar bombardment, the sputtering yield of Ta increases with angle of ion incidence slower than secθ, producing a maximum etch rate at normal incidence. Above a critical pressure of O2, however, the yield increases faster than secθ dependence, producing a maximum etch rate at a non-normal angle of incidence. The third example is the effect of angle of incidence on the preferential sputtering of Al relative to Cu in Al-5% Cu thin films. Films deposited by evaporation with simultaneous Ar ion bombardment at 500 eV show a depletion of Al relative to Cu. This composition change is enhanced by increasing the angle of incidence away from normal, resulting in a higher Cu concentration in a film deposited on a tilted surface. Finally, a mechanism is described for the generation of oriented microstructure in films deposited under simultaneous glancing-angle ion bombardment, demonstrated previously for Nb. Grain orientations are selected which allow channelling of the ion beam. These results show that the shape, composition and microstructure of films deposited under ion bombardment respond to changes in angle of incidence, and that these effects need further study and modeling.

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