Rozprawy doktorskie na temat „Plasma etching”
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Chen, Hsin-Yi. "Inductively coupled plasma etching of InP". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0021/MQ54126.pdf.
Pełny tekst źródłaParks, Joseph Worthy Jr. "Microscopic numerical analysis of semiconductor devices with application to avalnache photodiodes". Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/13539.
Pełny tekst źródłaBaker, Michael Douglas. "In-situ monitoring of reactive ion etching". Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/15352.
Pełny tekst źródłaZhu, Hongbin. "Control of Plasma Etching of Semiconductor Surfaces". Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1354%5F1%5Fm.pdf&type=application/pdf.
Pełny tekst źródłaJamali, Arash. "Etching of wood by glow-discharge plasma". Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/39882.
Pełny tekst źródłaGoodlin, Brian E. 1974. "Multivariate endpoint detection of plasma etching processes". Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8498.
Pełny tekst źródłaIncludes bibliographical references.
In plasma etching process it is critical to know when the film being etched has cleared to the underlying film, i.e. to detect endpoint, in order to achieve the desired device performance in the resulting integrated circuit. The most highly utilized sensor technology for determining endpoint has historically been optical emission spectroscopy (OES), because it is both non-invasive and highly sensitive to chemical changes in the reactor. Historically, the intensity of one emission peak corresponding to a reactant or product in the etch process was tracked over time, leading to a single-wavelength endpoint trace. At endpoint, the concentrations of reactant and product species undergo a step change that is detectable in the optical emission endpoint trace for many plasma etching processes. Unfortunately, for several critical etching steps (contact and via), the exposed area of the film being etched is very low (<1%, with the rest being masked with photoresist),. and this traditional method of endpoint detection has failed because of the low signal-to-noise ratio at endpoint. Our work has provided a way to improve the endpoint detection sensitivity by a factor of approximately 5-6, so that endpoint can be adequately detected for these low open area etching steps. By utilizing CCD array detection for OES sensors, it is possible to rapidly collect (2-10 Hz) full spectral data (200-900 nm in wavelength), consisting of over 1000 discrete wavelength channels from a plasma etching process. By appropriately utilizing this multi-wavelength data, we have been able to achieve significant improvements in sensitivity. Our work has focused on characterizing, analyzing, and developing new multivariate (multi-wavelength) strategies to optimize the sensitivity of the endpoint detector.
(cont.) This thesis provides a thorough comparison of several different multivariate techniques for improving endpoint detection sensitivity and robustness, both experimentally and theoretically. The techniques compared include: 1) multivariate statistical process control metrics such as Hotelling's T2; 2) chemometrics techniques such as principal component analysis (PCA) and T2 and Q statistics based on PCA, evolving window factor analysis (EWFA); 3) discriminant analysis; and 4) a new methodology called the Multi-wavelength statistic weighted by Signal-to-Noise ratio or MSN Statistic. A quantitative methodology based on signal-to-noise analysis was employed to compare the various techniques. Following this type of analysis, the MSN statistic was developed to theoretically provide the optimal improvement in endpoint detection sensitivity given certain assumptions about the nature of the noise in the data. Applying the MSN statistic to experimentally collected endpoint data confirmed that it did give superior results. By utilizing information about the direction (in the multivariate space) of endpoint from prior runs, the MSN statistic showed significant improvement over the traditional multivariate T2 statistic, that does not use any prior knowledge for detection. Another important aspect of the work was in characterizing the nature of multivariate noise, and understanding how different multivariate algorithms treat the different forms of multivariate noise. In general, we found that multivariate noise could be broadly classified into two components ...
by Brian E. Goodlin.
Ph.D.
Fukumoto, Hiroshi. "Model Analysis of Plasma-Surface Interactions during Silicon Oxide Etching in Fluorocarbon Plasmas". 京都大学 (Kyoto University), 2012. http://hdl.handle.net/2433/158076.
Pełny tekst źródłaBrihoum, Mélissa. "Miniaturisation des grilles de transistors : Etude de l'intérêt des plasmas pulsés". Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENT073.
Pełny tekst źródłaMicroelectronics industry is based on the continuous transistor downscaling. By the year 2016, the 16nm technological node would be achieved, so that structures with nanometric dimensions and high aspect ratio would have to be etch. However, traditional etching processes shows major limitations in terms of pattern profiles control and critical dimensions when such structures have to be etch. The encountered problems are related directly to intrinsic limitations of plasmas processes but also to the emergence of new phenomena’s when the dimensions of structures to etch become nanometric. In the framework of this thesis, a new strategy to produce plasma has been evaluated to develop etching plasmas processes adapted to next integration circuit generations: the pulsed plasmas. Over a first phase, the impact of plasma pulsing parameters (frequency and duty cycle) on the plasma physico-chemical characteristics has been highlight. This has been achievable thanks to advanced plasma analyse techniques (VUV broad band absorption spectroscopy, ion flux probe, retarding electrical field analyser…) developed to allow time resolved measurements. For the neutral flux, diagnostics have revealed that duty cycle is THE key control knob to tune the plasma. Indeed, a low duty cycle leads to reduced parent gas fragmentation and thus a reduced chemical reactivity. On the other hand, in electronegative plasmas and for constant RF power, we have demonstrated that ion energy is considerably increased when the ions flux is decreased (i.e. when the duty cycle is decreased). Then, surface analyses (XPS, SEM, Raman spectroscopy…) brought out the mechanisms involved during the plasma-surface interaction. Deeper comprehension of impact of pulsing parameters enables to develop pulsed plasmas processes more easily. These works are focused on the top of the transistor gate and deal with the following steps: HBr cure, Si-ARC etching, poly-silicon etching. HBr cure is an essential pre-treatment of the 193 nm photoresist to decrease the Line Width Roughness (LWR) of transistor gate. During this step, a carbon rich layer is formed on the surface of the resist pattern and degrades the beneficial action of UV plasma light on LWR reduction. Thanks to use of pulsed plasmas, the origin of this carbon rich layer has been highlight: UV induced modifications in polymer bulk lead to outgassing of volatiles carbon-based products in the plasma. These carbon containing moieties are fragmented by electron impact dissociation reaction in the plasma, which create sticking carbon based precursors available for re-deposition on the resist patterns. The impact of this layer on the LWR and resist pattern reflow is studied, and a possible mechanical origin (i.e. buckling instabilities) is highlighted. Finally, we showed that the use of pulsed HBr curing plasma allows to reduce and control the thickness of the graphite-like layer and to obtain LWR reduction that are comparable to VUV treatment only. The Si-ARC layer, used as hard mask, and the poly-silicon gate etching are based on the use of fluorocarbon plasmas. However, in these plasmas, the production of radicals enable for the polymerisation is decreased when the duty cycle is reduced. It leads to loss of both anisotropy and selectivity. Synchronised pulsed plasmas are then not adapted to such etching processes. To overcome this problem, a new way to produce plasma has been studied: the ICP source power is maintained constant and only the bias power is pulsed. Regarding Si-ARC etching, very anisotropic profiles are obtained and the Si-ARC to resist selectivity is enhanced while pulsing the rf bias to the wafer. In the case of poly-silicon etching, the ARDE effects are significantly reduced while the selectivity regarding the oxide is improved. These results are very promising for the development of polymerising plasmas processes
Astell-Burt, P. J. "Studies on etching and polymer deposition in halocarbon plasmas". Thesis, University of Oxford, 1987. http://ora.ox.ac.uk/objects/uuid:d8fd1069-a66b-4372-8ba0-b9ca5367445c.
Pełny tekst źródłaToogood, Matthew John. "Studies of the chemistry of plasmas used for semiconductor etching". Thesis, University of Oxford, 1991. http://ora.ox.ac.uk/objects/uuid:e234bbaa-d6e6-4ac8-a3dd-aa9a2c1b1e39.
Pełny tekst źródłaOhta, Hiroaki. "Molecular dynamics simulation of the plasma-surface interaction during plasma etching processes". Kyoto University, 2004. http://hdl.handle.net/2433/145252.
Pełny tekst źródła0048
新制・課程博士
博士(エネルギー科学)
甲第11119号
エネ博第97号
新制||エネ||27(附属図書館)
22669
UT51-2004-L916
京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻
(主査)教授 近藤 克己, 教授 佐野 史道, 教授 斧 髙一
学位規則第4条第1項該当
Steiner, Pinckney Alston IV. "Anisotropic low-energy electron-enhanced etching of semiconductors in DC plasma". Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/27060.
Pełny tekst źródłaSmith, Scott Alan. "INDUCTIVELY COUPLED PLASMA ETCHING OF III-N SEMICONDUCTORS". NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-05082002-162142/.
Pełny tekst źródłaSamara, Vladimir. "Negative ions and neutral beams in plasma etching". Thesis, Open University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534386.
Pełny tekst źródłaCarter, A. J. "The plasma etching of III-V semiconductor materials". Thesis, Cardiff University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305164.
Pełny tekst źródłaRizvi, Syed Shabbar Abbas. "Inductively coupled Ar/Clâ‚‚ plasma etching of GaN". Thesis, University of Ulster, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288895.
Pełny tekst źródłaTao, Benjamin A. (Benjamin Albert). "Non-perfluorocompound chemistries for plasma etching of dielectrics". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40603.
Pełny tekst źródłaDalton, Timothy Joseph. "Pattern dependencies in the plasma etching of polysilicon". Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/11655.
Pełny tekst źródłaKrautschik, Christof Gabriel 1957. "Impedance determination of a RF plasma discharge by external measurements". Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277141.
Pełny tekst źródłaOkpalugo, Osmond A. "Characteristics of argon-chlorine inductively coupled plasmas for plasma surface modification and etching". Thesis, University of Ulster, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399684.
Pełny tekst źródłaFagan, James G. "Reactive ion etching of polymide films using a radio frequency discharge /". Online version of thesis, 1987. http://hdl.handle.net/1850/10284.
Pełny tekst źródłaNakazaki, Nobuya. "A Study of Plasma-Induced Surface Roughness and Ripple Formation during Silicon Etching in Inductively Coupled Chlorine Plasmas". 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215513.
Pełny tekst źródłaPerng, John Kangchun. "High Aspect-Ratio Nanoscale Etching in Silicon using Electron Beam Lithography and Deep Reactive Ion Etching (DRIE) Technique". Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11543.
Pełny tekst źródłaBooth, J. P. "Laser studies of species involved in plasma etching processes". Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233432.
Pełny tekst źródłaRodgers, Seth Thomas 1970. "Multiscale modeling of chemical vapor deposition and plasma etching". Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/28219.
Pełny tekst źródłaIncludes bibliographical references.
In this work, a framework and a set of modeling tools capable of describing systems with key processes occurring on widely separated length and time scales has been developed. The major focus of this work is linking atomistic and continuum descriptions of gas phase transport. This problem is of considerable practical interest, as most etching and CVD processes are run at low pressures ~ 1 torr or less. Under these conditions, the continuum diffusion models used to describe flow and transport in a typical reactor will fail below scales of a few hundred microns, and thus are not useful in describing transport in and around microscale topography. This is a serious limitation, as such topography is present in most microelectronic devices. Two methods for linking discrete particle (or feature scale) and continuum models of precursor transport are presented. The discrete and continuum models are coupled by boundary conditions at their mutual interface (just above any reactive surface with microscale detail) The first approach employs an effective reactivity function e,, which is computed through a hybrid probabilistic-deterministic MC method e. can be interpreted as a representation of the average fate of molecules entering the feature scale domain from the macroscopic model. An example of tungsten CVD over a substrate with surface topography typical of modern microelectronic devices is presented. A second, deterministic technique was also developed as an improvement on the Monte Carlo approach. The deterministic method uses the matrix of transmission probabilities, or shape kernel, to summarize all microscale events in a fashion consistent with a continuum macroscopic model. The deterministic linking algorithm is over 1,000 times faster than the previously presented MC method. The speed advantage enables simulation of detailed chemistry. Plasma etching presents a very similar multiscale problem and a strategy for linked plasma etching simulations is presented. Finally, a study of ionized physical vapor deposition of aluminum is presented as an example of atomistic-continuum linking. Molecular dynamics simulations are used to represent atomistic events. The Molecular Dynamics results are summarized in a manner that allows the combination of atomistic information with a continuum (level -set) model for evolution of the deposited metal film.
by Seth Thomas Rodgers.
Ph.D.
Kong, Yung 1967. "Particle contamination in sulfur-hexafluoride/argon plasma etching process". Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/277919.
Pełny tekst źródłaHaque, Yasmeen. "Deposition of plasma polymerized thin films /". Thesis, Connect to this title online; UW restricted, 1985. http://hdl.handle.net/1773/9848.
Pełny tekst źródłaVas̆eková, Eva. "Spectroscopic studies of etching gases and microwave diagnostics of plasmas related to the semiconductor industry". n.p, 2006. http://physics.open.ac.uk/~ev295/!MASTER_THESIS.pdf.
Pełny tekst źródłaSucksmith, John Peter. "Studies of plasmas used for semiconductor etching". Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335818.
Pełny tekst źródłaSlapelis, Linda. "Plasma modification of poly(ester sulfonic) acid anionomeric membranes /". Online version of thesis, 1994. http://hdl.handle.net/1850/11445.
Pełny tekst źródłaBose, Abhijit Frank. "Diagnostics and control of plasma etching reactors for semiconductor manufacturing /". [S.l.] : [s.n.], 1995. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=11224.
Pełny tekst źródłaNishimoto, Keane T. (Keane Takeshi) 1981. "A study of plasma etching for use on active metals". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33914.
Pełny tekst źródłaIncludes bibliographical references (leaves 62-63).
Active metals can be used as a getter pump, removing impurities in ultra-pure high vacuum environments. To relieve the difficulties involved with the transportation, storage and handling of these metals, a process is being developed to create a protective coating by removing the active metal component from the surface of a mixture of the active metal and a stable element via immersion in a wet chemical bath. It is the purpose of this thesis to investigate the utility of a plasma etching process in the removal of the active metal. A decision tree for the selection of a suitable etchant gas was developed and experiments were conducted to validate the process. Magnesium coated glass slides were etched with chlorine, fluorine, and fluorocarbon gasses alone and in the presence of argon to determine which chemistry would etch the fastest. Magnesium was chosen because it was the easiest to handle among the active metals. It was determined that chlorine gas with argon provided the highest etch rate. Next, a set of factorial experiments were conducted to determine the sensitivity of the etch process to changing radio frequency power input, chamber pressure, and the ratio of chlorine to argon.
(cont.) Factor levels were arranged in an orthogonal array and the main effects of each parameter were estimated using analysis of means. It was found that the etch rate increases strongly with increasing power and decreasing amounts of chlorine. Dependence on pressure was less pronounced. These results indicate that the etching mechanism is dependent on physical sputtering. Etch rates of up to 30 nm/min were achieved at 350 W power, 20 mTorr chamber pressure, and a 10%/90% chlorine to argon ratio. In conclusion, although the etch rate is not currently high enough for practical use, the steps in the decision tree were validated by the first set of experiments while the second set was able to characterize the basic mechanism of the etch process.
by Keane T. Nishimoto.
S.M.
Tsuda, Mutsumi. "A Study of Plasma-Surface Interactions in Plasma Etching with Chlorine-and Bromine-based Chemistries". 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/147670.
Pełny tekst źródłaHaass, Moritz. "Développement de procédés de gravure à base de plasmas réactifs pulsés Pulsed plasmas for etch applications". Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00820065.
Pełny tekst źródłaYeager, John David. "Design and development of metal-polymer film systems for flexible electrodes used in cortical mapping in rats". Pullman, Wash. : Washington State University, 2008. http://www.dissertations.wsu.edu/Thesis/Summer2008/j_yeager_070908.pdf.
Pełny tekst źródłaTitle from PDF title page (viewed on Mar. 11, 2009). "School of Mechanical and Materials Engineering." Includes bibliographical references.
Boysen, Christopher J. "An analysis and development of controls for exposures to maintenance personnel working on the plasma metal etchers". Online version, 1998. http://www.uwstout.edu/lib/thesis/1998/1998boysenc.pdf.
Pełny tekst źródłaXuan, Guangchi. "Plasmaless automated xenon difluoride MEMS etching system development and application". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 71 p, 2006. http://proquest.umi.com/pqdweb?did=1163250891&sid=1&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Pełny tekst źródłaShustin, E. G., N. V. Isaev, I. L. Klykov i V. V. Peskov. "Plasma Processing Reactor on a Base of Beam Plasma Discharge for Producing and Processing Nanomaterials". Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35407.
Pełny tekst źródłaEden, Samuel Peter. "Spectroscopic and electron impact studies of molecules relevant to plasma etching". Thesis, University College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407575.
Pełny tekst źródłaLane, Jennifer M. (Jennifer Marie) 1977. "A fundamental study of feature evolution during high density plasma etching". Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80245.
Pełny tekst źródłaIncludes bibliographical references (leaves 91-94).
by Jennifer M. Lane.
M.Eng.and S.B.
Mahorowala, Arpan P. (Arpan Pravin) 1970. "Feature profile evolution during the high density plasma etching of polysilicon". Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/50514.
Pełny tekst źródłaIncludes bibliographical references (p. 185-191).
This thesis work deals with one of the critical steps in the manufacturing of modem integrated circuits - the plasma etching of thin polysilicon films used to form the metaloxide- semiconductor transistor gate. The etching of very small features (-0.25 jim) in the -2500 A thick films, performed at low operating pressures (-10 mTorr), must be accompanied with minimal etching artifacts that can degrade device performance. This thesis aims to understand the causes for the etching artifacts observed during the etching of polysilicon line-and-space features in C12 and HBr plasmas so that better etching recipes can be developed. The second goal of this work was to develop a generalized simulator capable of predicting the feature profile evolution for the above plasma etching system as well as systems involving other materials and chemistries. The 2V2-dimensional simulator developed used Monte Carlo techniques to compute the transport and surface kinetics combined with a cellular representation of the feature. Using the Monte Carlo algorithm permitted the incorporation of all dominant physical and chemical mechanisms of the etching process such as angle-dependent ionenhanced etching, physical sputtering, ion scattering, surface recombination, plasma deposition, and line-of-sight re-deposition without encountering numerical difficulties. The technique allowed the calculation of surface kinetics rates based on the surface composition; simultaneous composition-dependent etching and deposition could be handled easily. A modification of the cellular representation of the feature was developed to determine neutral species interactions with the surface correctly. A surface normal calculation algorithm involving least-squares fitting of the surface was developed to handle specular ion scattering. Designed sets of plasma etching experiments were performed on photoresist masked and silicon oxide-masked polysilicon samples using C12 and HBr chemistries varying the inductive power (controls the ion density, radical concentrations), the rf biasing power (controls the ion energy) and the gas flowrate (controls the reactant and product concentrations). The interesting features exhibited in the experimental profiles included: 1) the increased sidewall deposition associated with photoresist-masking and isolated features, 2) the greater curvature of the sidewalls associated with the combination of photoresist and Cl2 plasmas, 3) the more vertical sidewalls achieved with HBr, 4) the double faceting of the feature sidewalls under etching conditions accompanied by significant deposition, 5) the delay in the onset of microtrenching at the feature bottom while etching photoresist-masked samples with C12, 6) the greater microtrenching exhibited with silicon oxide-masking and C12 plasmas, and 7) the lack of microtrenching for the HBr etching. The experimental results suggested strong dependencies of microtrenching, tapered sidewall profiles and photoresist-mask faceting on the feature aspect ratio, product formation rate and product residence time in the etching chamber. The etching artifacts were explained using the profile evolution simulator. The microtrenching was associated with two mechanisms - ion scattering from tapered sidewalls and the focussing of directional ions by bowed sidewalls onto the feature bottom. The former mechanism led to trenching initially while the latter mechanism gained importance midway during the etching. The absence of tapered sidewalls initially and the relatively straight sidewall profiles developed during the etching explained the non-occurrence of microtrenches when using HBr. Under processing conditions accompanied by significant deposition, facets at two distinct angles were predicted. The top facet depended on the composition of the material on the photoresist-mask line and its etching angular dependence. The lower facet angle and the polysilicon sidewall profile were governed by the feature aspect ratio, the sticking probabilities and fluxes of the depositing material, and the depositing material etching angular dependence. The phenomenon of feature charging was incorporated in the Monte Carlo simulator to understand its role in the profile evolution. Two electrical approximations were made for the feature - the perfectly insulating and a novel resistive approximation. With an insulating feature, the potential profiles were obtained by determining the space charge on the feature surface and solving Poisson's equation over the entire simulation domain. Calculation of the potential profiles with the resistive feature representation involved treating the feature as a large resistive network, determining the steady-state currents to the feature surface and solving the conductivity equation and Laplace's equation in the solid and gas, respectively. The role surface and bulk conductivities played on the potential profiles were studied. The potential profile in a completely etched polysilicon (conducting) feature with a silicon oxide (insulating) feature bottom was generated. Higher ion currents were calculated at the lower part of the polysilicon sidewall. These currents can etch the passivating material deposited at lower portion of the sidewall enabling spontaneous etching of the sidewall, and cause notching of the sidewall.
by Arpan P. Mahorowala.
Ph.D.
Lu, Kan P. "Surface modulation of fluoropolymers for the improvement of adhesion : O₂-CF₄-Ar radio frequency plasma modification of poly (tetrafluoroethylene) /". Online version of thesis, 1994. http://hdl.handle.net/1850/11696.
Pełny tekst źródłaBlanc, Romuald. "Développement et caractérisation de procédés de gravure des espaceurs Si3N4 pour les technologies FDSOI". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT036/document.
Pełny tekst źródłaIn CMOS technologies on FDSOI substrate, the silicon recess in transistor's source/drain regions caused by multiple etch steps is a critical parameter. The plasma etching of Si3N4 spacers, which occurs after the gate etch step, must allow the fabrication of straight spacer profiles which will define the effective channel length under the gate, while minimizing the consumption of the underlying silicon thin film. Moreover, the silicon surface state generated by the spacers etching must not prevent the epitaxial silicon growth used for the realization of raised source/drain regions.The study of current spacers etch processes based on CHxFy/O2 chemistries shows that silicon is consummated by oxidation when the plasma lands on the silicon surface. Furthermore, the XPS analysis shows that carbon is implanted in the silicon substrate by plasma ions, and that it inhibits the silicon epitaxial regrowth. We are able to reduce the implanted carbon concentration without any additional silicon recess by using non-oxidizing plasma post-treatments based on hydrogen.After identifying the limitations of current etch processes, we developed and characterized Si3N4 spacers etch processes using synchronously pulsed CH3F/O2/He plasmas. The modulation in short pulses with low duty cycles decreases the dose of high energy ions bombarding the substrate, which allows to reduce the oxidized silicon thickness as well as the concentration of implanted carbon. The addition in the plasma of a Si-containing gas, SiCl4 or SiF4, also leads to a reduction of the silicon consumption thanks to the deposition of a SiOxFy layer by radicals from the gas phase. The best result is obtained with a CH3F/O2/He plasmas pulsed at 1 kHz and 10% duty cycle with the addition of 5 or 10 sccm of SiF4 : the silicon recess is then almost zero.We also developed and evaluated an alternative etching technique, based on the implantation of He+ and H+ ions followed by a HF wet etch, for the etching of Si3N4 spacers. This innovative etch process does not generate any silicon recess and shows some promising results
Choi, Tae-Seop. "Copper, silver, and gold etching with H₂ and CH₄ based plasmas". Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53043.
Pełny tekst źródłaSteel, William H. "On the properties of plasma crystals". Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326021.
Pełny tekst źródłaJin, Weidong 1975. "Study of plasma-surface kinetics and feature profile simulation of poly-silicon etching in Cl²/HBr plasma". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/28357.
Pełny tekst źródłaIncludes bibliographical references.
This work characterized the Cl2/HBr ion enhanced plasma-surface interactions with poly-silicon as a function of the gas composition, ion energy, ion incident angle and other important process parameters. A realistic inductively coupled plasma beam apparatus capable of generating ions and neutrals representative of real commercial etcher was constructed and utilized to simulate accurately a high density plasma environment. Etching rate of poly- silicon, the oxygen effect and loading effect are quantified to better describe the etching of patterned poly-silicon in fabricating the gate electrode of a transistor in VLSI manufacturing process. The kinetics model derived from these measurements are incorporated into a Monte Carlo based feature profile simulator, and profile evolution has been simulated under various processing conditions. The realistic plasma beam was used to measure the etching yields of poly-silicon with Cl2/HBr chemistry at different ion energies. The etching yields were found to scale linearly with ... where the threshold energies, Eth are 10 eV for both Cl2 and HBr. The etching yields at different neutral-to-ion flux ratio were measured and the sticking coefficients are derived for reactive neutrals for Cl2 and HBr. The sticking coefficient for HBr system is lower probably due to the relatively larger size of bromine atom compared with chlorine and its relatively lower chemical reactivity. The etching yields for mixed Cl2+HBr plasma at different compositions were also measured.
(cont.) The etching yield by the HBr plasma beam is similar to the C12 plasma beam, although the etching rate by the HBr plasma is about 40% lower due to the lower ion flux. The angular dependence of etching yield by both Cl2 and HBr strongly suggests the mechanism of ion enhanced chemical etching. With Cl2 plasma beam, the etching yield almost keeps constant until the off-normal ion incident angle increased to 45⁰, while with the HBr plasma beam, the etching yield starts dropping even with small off-normal angle. The etching yield by Cl2+HBr plasma at different composition exhibits a similar trend as pure HBr. The difference of angular dependent etching yield between Cl2 and HBr might contribute to the difference of feature profile evolution in these two chemistries, i.e., more anisotropic etching in HBr plasma, as suggested by Monte Carlo feature profile evolution simulation. The XPS peak for Cl(2p), Br(3d), and Si(2p) are integrated to quantify the relative concentration of different species on the sample surface after exposure to the plasma beam. The Cl coverage after etching with pure Cl2 plasma beam is about 1.4 times higher than the Br coverage after etching with pure HBr plasma beam. The lower Br coverage is likely due to site blocking by coadsorbed H and adjacent adsorption site blocking by the larger Br atom. The Si(2p) was deconvoluted to differentiate Si(bulk), SiCl, SiCl2 and SiCl3. About 70% of the chlorine adsorbed onto the surface is in the form of di- and tri-chloride. Similar results are observed for bromine. Inversion method was used to extract the depth profile from the angular resolved XPS measurement. The halogenation layer is about 15 - 25 [Angstroms] thick, and the concentration of halogen decays exponentially as depth increases ...
by Weidong Jin.
Ph.D.
Laudrel, Edouard. "Gravure de titane pour applications biomédicales". Thesis, Orléans, 2017. http://www.theses.fr/2017ORLE2035.
Pełny tekst źródłaMiniaturization efforts are required in the field of implantable active devices in order to limit invasiveness and reduce the risks of complications following surgical operations. Progression margins for the reduction of dimensions tend to be reduced for current systems such as cardiac pacemakers, neurostimulators or in vivo autonomous sensors. A technological break is needed to push the limits of current systems. Titanium is a material with biocompatibility properties. It is stable and inert in contact with the human tissues.Moreover, its mechanical characteristics make it a promising material for the development of implantable microsystems. As a part of the MISTIC R&D project (Micro-Structuring of Titanium for Innovations in Cardiology), the main objective of this PhD thesis is to develop a technological brick on the deep etching of titanium for the integration of microsystems in active implantable devices. Studies on the deep etching of titanium into Cl₂ plasma have been carried out in order to determine the mechanisms involved. Further, by adding fluorinated species in the process through the creation of a new reaction pathway, an increase in the titanium etch rate and an improvement of the selectivity with the nickel hard mask were achieved. A process for titanium etching over a depth of 300 μm has been developed on 100 mm diameter wafers. The application of the results of these studies and the transfer of the process to the full wafer etching made it possible to produce the demonstrators with titanium-based electrical feedthrough
Morris, Bryan George Oneal. "In situ monitoring of reactive ion etching". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31688.
Pełny tekst źródłaCommittee Chair: May, Gary; Committee Member: Brand,Oliver; Committee Member: Hasler,Paul; Committee Member: Kohl,Paul; Committee Member: Shamma,Jeff. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Little, Thomas William. "Surface science studies on the interaction of nitrogen trifluoride ion beams and plasmas with silicon /". Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/10613.
Pełny tekst źródłaWohlfart, Ellen [Verfasser]. "Nanopatterning of poly(ethylene terephthalate) by plasma etching / vorgelegt von Ellen Wohlfart". Stuttgart : Max-Planck-Inst. für Metallforschung, 2010. http://d-nb.info/1012342662/34.
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