Parylene film thicknesses of only a few microns were etched and no attempt at har structures was made. The seasoning of plasma etching reactors will be discussed using results from a computational investigation of psi etching in chlorine plasmas. Reactive ion etching was the main technology, but new techniques were developed. Dry etching uses gas reactant species to etch film plasma etching typically high pressure, no ion bombardment substrate placed on grounded electrode reactive ion etching typically lower pressures, ion bombardment substrate placed on powered electrode ion beam methods plasma is generated in a separate chamber and.
The most common plasma etch configurations are reactive ion etch rie, planar etch pe, inductively coupled. Ee143 f2010 lecture 14 1 etching etching terminology etching considerations for ics wet etching reactive ion etching plasma etching professor n cheung, u. This chapter discusses the deep reactive ion etching in detail. Plasma in daily life and ic plasma etching plasma immersion ion implantation piii plasma deposition plasma stripping ashing plasma in ic manufacturing. Ion enhanced etching or reactive ion etching rie it has been observed that chemical and physical components of plasma etching do not always act independently both in terms of net etch rate and in resulting etch profile. In the nineties new techniques, such as electron cyclotron resonance ecr. Plasma etching, dry etching and reactive ion etching rie all describe processing techniques that have in common the fourth state of matter. Introduction to plasma etching willson research group. Reactive ion etching is an anisotropic processreactive ion etching is an anisotropic process. Weve developed a wide range of solutions for plasma cleaning, plasma etching, reactive ion etching rie, plasma treatment, surface modification, and other facets of plasma processing. Mechanisms of silicon etching in fluorine and chlorine. Reactive ion etching rie is a plasma etching technology to fabricate micro and nanostructures. The effect of rf power duty cycle on the ion energy transition is discussed. Accepted manuscript open access factors influencing ion.
Plasma plasma is a partially ionized gas composed of equal numbers of positive and negative charges, as well. Lecture 1 definition of a plasma, examples, plasma temperature, debye shielding, plasma criteria duration. As a difference with ln etching using fluridebased gases the chemical reaction between li ion and the f does not take place and, as a consequence, the production of lif is completely eliminated. New plasma technologies for atomic scale precision etching. Reactive species in plasma found to accelerate dry etching. The surface of the component is usually etched with a reactive process gas which gives both a chemical and physical effect on the surface. Evidence for antisynergism between ionassisted etching and. Reactive ion etching rie is an etching technology used in microfabrication. Plasma etching is a synergistic process of both chemical and physical etching, which makes it distinctive from conventional wet etching. Plasma process monitoring reactive ion etching designed to give better control of selectivity and anisotropy independently. The transport of etch products, passivation of walls. When the ion energy was below the iae threshold, an unexpected substantial etching rate was observed, independent of ion. Usyd senior plasma physics lectures 42,534 views 9. Selfconsistent computations of electric fields efields and ion orbits inside trenches were done in order to verify hashimotos hypothesis of damage that is induced during plasma processing.
The ion energy distributions were measured by retarding field energy analyzer. The sources of metal contamination in production lines have been traced to virtually all tools, including furnaces and epitaxial reactors, ion implanters, plasma and reactive ion etching equipment, wet cleaning and etching chemicals, and wafer handlers and equipment. Ion beam etching or milling is a dry plasma etch method which utilizes a remote broad beam ionplasma source to remove substrate material by physical inert gas andor chemical reactive gas. Lower operating pressures result in higher anisotropy. Reactiveion etching rie vs deep reactiveion etching drie. Publishers pdf, also known as version of record includes final page, issue and volume numbers. Reactive ion etching rie is a high resolution mechanism for etching materials using reactive gas discharges. Plasma etching is widely used for etching nanoscale features because it can produce vertical sidewall profiles with little or no undercut. Plasma etching techniques are typically classed by the configuration of the electrodes. The pe100 is a complete plasma treatment solution capable of reactive ion etching, plasma functionalization, and more. Pdf plasmaetching processes for ulsi semiconductor circuits. The plasma source, known as etch species, can be either charged ions or neutral atoms and radicals.
Mechanisms for plasma and reactive ion etchfront roughening. In the plasmaetching mode, the electrons accelerated by the applied rf. Weve developed a wide range of solutions for plasma cleaning, plasma etching, reactive ion etching rie. Kushner iowa state university department of electrical and computer engineering. Dry etching overview the college of engineering at the. Reactive ion etching of silicon using lowpower plasma etcher. Rem, voor een commissie aangewezen door het college voor promoties in het openbaar te verdedigen op maandag december 1999 om 16. Ion enhanced etching or reactive ion etching rie it has been observed that chemical and physical components of plasma etching do not always act independently both in terms of net etch rate and in. Evidence for antisynergism between ionassisted etching. Reactive ion etching of silicon using fbased chemistry. Dry etching substrates are immersed in a reactive gas plasma. This model is perfect for manufacturers, medical facilities, universities, research facilities, or any other company in need of a costeffective, productiongrade plasma processing solution. Reactive ion etching of gaas and algaas has been performed by using ccl2f202ar 2 and cc12f2he mixtures 3, while plasma etching at higher pressures than are typically associated with.
Etching different etching processes are selected depending upon the particular material to be removed. Highenergy ions from the plasma attack the wafer surface and react with it. Dry etching uses gas reactant species to etch film plasma etching typically high pressure, no ion bombardment substrate placed on grounded electrode reactive ion etching typically lower. Crystallographic orientation dependent reactive ion. Plasma etch technologies for the development of ultrasmall feature. Rie uses chemically reactive plasma to remove deposited material on the wafer. Ion beam etching or milling is a dry plasma etch method which utilizes a remote broad beam ion plasma source to remove substrate material by physical inert gas andor chemical reactive gas means. Ee143 f2010 lecture 14 etching university of california. Handbook of plasma processing technology 1st edition fundamental, etching, deposition and surface interactions. Plasma etching of materials can proceed via a combination of physical and chemical mechanisms. In this way, energetic ions work in synergy with neutral chemical species from the plasma to remove film from the wafer surface. The ion energies should be t1, where t1 is the threshold for etching the passivated top monolayer. Such anisotropy is maximized in deep reactive ion etching. Argon plasma inductively coupled plasma reactive ion.
Pdf the role of plasma etching in the semiconductor technology upon switching from the microscale to. Berkeley ee143 f2010 lecture 15 1 reactive ion etching r ie plasma wafers rf. Silicon etching in fluorine and chlorinecontaining plasmas 1711 as pressure is decreased below about loomtorr, the potential across the discharge characteristically increases, and with this there is a corresponding rise in sheath potentials. Reactiveion etching rie vs deep reactiveion etching drie reactiveion etching rie and deep reactiveion etching drie are both dry etching techniques used in microelectromechanical systems. On the contrary, the reactive ion etching and the neutral plasma chemical etching are found to be efficient for the preferential removal of one. Reactive ion etching systems rie plasma etching samco inc.
Like other dry plasma etch techniques, the typical. A plasma is a quasineutral gas of charged and neutral particles quasineutral means that overall the net charge of the plasma is approximately zero, because fluctuations in charge density in the plasma are small in magnitude and short in duration a plasma is created whenever gases are forced to conduct electric current. It involves a highspeed stream of glow discharge plasma of an appropriate gas mixture being shot in pulses at a sample. Ion orbits in plasma etching of semiconductors request pdf. Etching is used in microfabrication to chemically remove layers from the surface of a wafer during manufacturing. Introduction to plasma etching university of texas at austin.
Rie is a type of dry etching which has different characteristics than wet etching. Plasma removal previously, plasma 14, 15, reactive ion beam ribe 16, and reactive ion 17, 18 etching of parylene in oxygen environments has been reported. Reactive ion etching of gaas and algaas has been performed by using ccl2f202ar 2 and cc12f2he mixtures 3, while plasma etching at higher pressures than are typically associated with rie has been reported for using ccl4, bcc12, and cl 2 0 2 46. Physical etching chemical etching reactive ion etching rie deep reactive ion etching drie plasma plasma partially ionized gas consisting of equal. Rie uses chemically reactive plasma to remove material deposited on wafers. Etchant additives inert gas purpose primary etchant selectivity control stablize plasma, dilute etchant examples see. The paper is devoted to the study of deep reactive ion etching of silicon using diode plasma etcher system with a lowpower source. Oxygen plasmas have been used to texture teflon 62 and other polymer materials 63,64. In partial fulfillment of the requirements for the degree of. Multiple mechanisms can lead to arde in plasma etching neutral shadowing ion shadowing differential charging knudsen transport solution to arde issues can depend on which mechanisms isare responsible in previous dielectric etch study, we observed that differential charging was a primary mechanism for classical arde. Plasma based dry etching rf power is used to drive chemical reactions plasma takes place of elevated temperatures or very reactive chemicals types. Silicon wafers were etched in a sulfur hexafluoride plasma and sulfur hexafluorideoxygen plasma.
The ion energies should be t1, where t1 is the threshold for etching. Types of plasma etching include inductively coupled plasma, reaction ion and plasma enhanced etching. Handbook of plasma processing technology 1st edition. Steve sirard technical director lam research corporation. Reactive ion etching rie vs deep reactive ion etching drie reactive ion etching rie and deep reactive ion etching drie are both dry etching techniques used in microelectromechanical systems memes fabrication. In plasma etch, the chemical etchant is introduced in the gas phase. During rie etching processes, volatile compounds are formed in interaction of sample surfaces and high. Ion energy distributions average plasma potential vp dc bias potential v bias 0 20. Dynamics of ionassisted etchingby petrus gerardus maria sebel. Reactive ion etching rie of sic in fluorinated plasmas has been developed to the. With the decrease of rf power duty cycle, the increase of ion energy and energy spread is observed and ion energy distribution changes from single peaked to bimodal. Deep reactive ion etching of silicon was studied in a sulfur hexafluoride plasma and sulfur hexafluorideoxygen plasma.
Lower ion energies, however, result in the lower etch rates and reduced g. Selective plasma etching of polymeric substrates for advanced. The plasma state describes a condition where one or more gases are held at a certain pressure and submitted to. It is a highly controllable process that can process a wide variety of materials, including. The plasma is generated under low pressure vacuum by an electromagnetic field. Jan 12, 2009 lecture 1 definition of a plasma, examples, plasma temperature, debye shielding, plasma criteria duration. Reactive ion etching systems rie etch process plasma. Figure 9 shows the roughening of teflon using oxygen plasma as the etching time is increased. Types of plasma etching include inductively coupled plasma, reaction ion and plasma. The most common plasma etch configurations are reactive ion etch rie, planar etch pe, inductively coupled plasma etch icp etch, or deep reactive ion etch drie etch. A dc bias enhances ion bombardment energy, resulting in some. Chamber pressure y pressure torr chemical plasma etching physical sputtering ion assisted etching 0. This anisotropic feature can be further enhanced by allowing the deposition of certain passivating films to occur along vertical sidewalls during the plasma reaction.
Plasma plasma is a partially ionized gas composed of equal numbers of positive and negative. The second step is exposure of the passivated layer to an etching plasma to remove. Etch rate uniformity across wafer key etch variables. Etching is a critically important process module, and every wafer undergoes many. Plasma etching is one of the main applications of plasma treatment and the plasma system known as a plasma etcher is commonly used in production of semiconductor devices. Tadigadapaplasma etching without ion bombardment, f 2 radicals etch sio 2 veryyy slowly since. The key applications and benefits of using ion beam technology for etching processes in comparison to technology such as plasma etching will be presented. At very low pressure, the ion energy is high, reactant.
Lower operating pressures result in higher anisotropy longer mean free path allows more directed acceleration of ions 2. Reactive ion etching systems rie etch process plasma etch. Plasma etching is an essential tool in todays world, enabling many of the technologies we take for granted. The surface of the component is usually etched with a reactive process gas which gives both a chemical and physical. The plasma is generated under low pressure by an electromagnetic field.
Reactive ion etching rie, also known as plasma etching or dry etching, and its extension deep reactive ion etching drie are. Plasma etching techniques including rie, pe, icp, and drie. An overview of ion beam generation is described, which will be followed by a discussion and presentation of some beneficial applications of ion beam technology. Plasma rie etching birck nanotechnology center fundamentals and applicationsfundamentals and applications 1. The layer to be etched is removed by chemical reactions andor physical means ion. Plasma etching is a form of plasma processing used to fabricate integrated circuits. Plasma atomic layer etching using conventional plasma. Plasma atomic layer etching using conventional plasma equipment.590 704 771 335 199 1361 563 985 432 1553 1523 904 451 165 347 557 1136 245 651 976 1400 72 436 1470 1296 1444 577 159 390 1553 1329 846 567 864 543 771 829 1233 635 135 1034 486 996 317 810 577