Chemically Assisted Ion Beam Etching of SiGe

1990 ◽  
Vol 204 ◽  
Author(s):  
O.J. Glembocki ◽  
S.M. Prokes ◽  
R.E. Stahlbush

ABSTRACTChemically assisted ion beam etching (CAIBE) of Si1−Gex films is reported. Ar+ ion sputtering in the presence of Cl2 background gas has been used to etch epitaxial films of Si1−xGex, with x ranging between 0 and 0.5. It is found that Si1−xGex, sputters more rapidly than Si, but less than Ge. The use of C12 gas enhances the sputter rates of SiGe as in the case of Si. Analysis of the etch rates indicates that the etch rate increase is due to an enhancement of the sputtering process, rather than a chemical effect.

1990 ◽  
Vol 203 ◽  
Author(s):  
Kyung W. Paik ◽  
Richard J. Saia ◽  
John J. Chera

ABSTRACTThe etch rates of BCB film in a reactive ion etcher(RIE) were measured using Ar, O2, O2+CF4, and O2+SF6 gas mixtures. Faster etch rates were obtained when CF4 and SF6 were added to oxygen, since the presence of atomic fluorine enhances the etch rate of organics, while also etching Si and SiO2 formed by exposure to oxygen gas. Surface compositional changes on the BCB film were observed by XPS after plasma modification. Pure O2 and O2+CF4 plasma oxidized the carbo-siloxane linkage (C-Si-O) of the BCB, resulting in the formation of SiO2 on the surface. The O2 +SF6 plasma, however, did not produce the surface SiO2, because of its faster Si and SiO2 etch rates. Ar ion sputtering following the plasma modification, restored the surface chemical composition to a state similar to the initial BCB surface.


MRS Advances ◽  
2017 ◽  
Vol 2 (4) ◽  
pp. 247-252
Author(s):  
Narasimhan Srinivasan ◽  
Katrina Rook ◽  
Ivan Berry ◽  
Binyamin Rubin ◽  
Frank Cerio

ABSTRACTWe investigate the feasibility of inert ion beam etch (IBE) for subtractive patterning of ReRAM-type structures. We report on the role of the angle-dependent ion beam etch rates in device area control and the minimization of sidewall re-deposition. The etch rates of key ReRAM materials are presented versus incidence angle and ion beam energy. As the ion beam voltage is increased, we demonstrate a significant enhancement in the relative etch rate at glancing incidence (for example, by a factor of 2 for HfO2). Since the feature sidewall is typically exposed to glancing incidence, this energy-dependence plays a role in optimization of the feature shape and in sidewall re-deposition removal.We present results of SRIM simulations to estimate depth of ion-bombardment damage to the TMO sidewall. Damage is minimized by minimizing ion energy; its depth can be reduced by roughly a factor of 5 over typical IBE energy ranges. For example, ion energies of less than ∼250 eV are indicated to maintain damage below ∼1nm. Multi-angle and multi-energy etch schemes are proposed to maximize sidewall angle and minimize damage, while eliminating re-deposition across the TMO. We utilize 2-D geometry/3-D etch model to simulate IBE patterning of tight-pitched ReRAM features, and generate etched feature shapes.


2002 ◽  
Vol 750 ◽  
Author(s):  
Patrick W. Leech ◽  
Geoffrey K. Reeves ◽  
Anthony S. Holland ◽  
Mark C. Ridgway

ABSTRACTDiamond films were implanted with Au or O ions at multiple energies in order to produce a uniform region of C vacancies. Analysis of the implanted films by Raman spectroscopy has shown that the proportion of non-diamond or amorphous carbon increased with dose (5 × 1013 − 5 × 1015 ions/cm2). For implantation with Au ions, a complete amorphisation near to the surface was evident at a dose of 5 × 1015 ions/cm2. We have examined the ion beam etch (IBE) rate of the films as a function of the implant species and dose. The etching experiments were performed using either Ar or Ar/O2 gases at a bias energy of 500 -1,000 eV. In Ar gas, the process of sputter etching has produced a similar increase in etch rate with dose for both the Au and O implants. In Ar/ O2 gases, the process of ion-enhanced chemical etching produced greater etch rates than obtained in Ar gas with higher rates for the Au than the O implants.


1989 ◽  
Vol 154 ◽  
Author(s):  
Kyung W. Paik ◽  
Arthur L. Ruoff

AbstractTwo kinds of ion beam etching techniques, Ar gas ion beam etching (IBE) and oxygen gas reactive ion beam etching (RIBE), were used for adhesion enhancement of the PI/Cu and Cu/PI interface, respectively.Ar gas IBE on Cu followed by deposition of PI film on the modified Cu surface can double the adhesion strength of spin-coated PI on Cu compared with unmodified Cu. The adhesion enhancement is due to increasing the surface contact area of the rough Cu surface to PI. However, a corrosion reaction happens at the polyamic acid (PAA) and Cu interface, resulting in the dissolution of Cu into the PI film and Cu oxide layer growth during curing of PI film. A Cr layer between Cu and spin-coated polyamic acid(PAA) is necessary to keep the Cu from dissolving in PAA and diffusing into PI. Ar IBE modification on Cu followed by deposition of a thin Cr layer on the modified Cu surface is recommended to enhance the adhesion strength of spin-coated PI on Cr.O2 RIBE on PI followed by evaporation of Cu on a modified PI increases the peel strength of Cu/PI by more than 25 times. The maximum peel strength of Cu on the PI modified by O2 RIBE is almost 70 grams/mm. The increase of adhesion is due to the mechanical interlocking of a unique structure of modified PI - a grass-like structure. This structure occurs because of the inhomogeniety of PI film - the presence of ordered and disordered phases in a PI film. In addition, the Cu/PI interface exhibits stability with thermal cycling and humidity, because the adhesion enhancement is mostly due to a mechanical effect and not a chemical effect. The diffusion of Cu into PI at various temperatures is not significant. Typically, Cu atoms can diffuse up to 300 at 400 °C in 1 hour. Another advantage of O2 RIBE on PI is the capability of enhancing the adhesion of the second PI layer on a first PI layer.These technologies allow the precise control of the adhesion strength of the PI/Cr/Cu and Cu/PI interfaces by independent variation of the beam energies, ion doses and angle of beam incidence. Also the ion source is easily installed in the same vacuum chamber for Cr and Cu evaporation. This provides low cost and simple operation.


1988 ◽  
Vol 128 ◽  
Author(s):  
J. M. E. Harper ◽  
S. E. Hörnström ◽  
P. J. Rudeck ◽  
R. M. Bradley

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.


1986 ◽  
Vol 75 ◽  
Author(s):  
Charles Garner

A chemically assisted ion beam etching (CAIBE) technique is described which employs an ion beam from an electron bombardment ion source and a directed flux of ClF3 neutrals. This technique enables the etching of tungsten foils and films in excess of 40 μm thick with good anisotropy and pattern definition over areas 5 mm2, and with a high degree of selectivity. (100) tungsten foils etched with this process exhibit preferred orientation etching, while polycrystalline tungsten films exhibit high etch rates approximately 80% that of (100) orientation tungsten.


Author(s):  
M. Spector ◽  
A. C. Brown

Ion beam etching and freeze fracture techniques were utilized in conjunction with scanning electron microscopy to study the ultrastructure of normal and diseased human hair. Topographical differences in the cuticular scale of normal and diseased hair were demonstrated in previous scanning electron microscope studies. In the present study, ion beam etching and freeze fracture techniques were utilized to reveal subsurface ultrastructural features of the cuticle and cortex.Samples of normal and diseased hair including monilethrix, pili torti, pili annulati, and hidrotic ectodermal dysplasia were cut from areas near the base of the hair. In preparation for ion beam etching, untreated hairs were mounted on conducting tape on a conducting silicon substrate. The hairs were ion beam etched by an 18 ky argon ion beam (5μA ion current) from an ETEC ion beam etching device. The ion beam was oriented perpendicular to the substrate. The specimen remained stationary in the beam for exposures of 6 to 8 minutes.


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