Fabrication and application of selfmasked silicon nanostructures. This paper examines the use of deep reactive ion etching drie of silicon with fluorine highdensity plasmas at cryogenic temperatures to produce silicon master molds for vertical microcantilever arrays used for controlling substrate stiffness for culturing living cells. Deepreactive ion etching enables highly anisotropic silicon etching with highselectivity relative to photoresists, making it feasible to fabricate structures with highaspect ratios i. Deep reactive ion etching of grassfree widelyspaced. Deep reactive ion etch deep reactive ion etch is a process where the kinetic energy from a plasma is used to activate a chemical reaction that carries out the etching. Deep reactive ion etching as a tool for nanostructure. Samples were carefully examined by xray photoelectron spectroscopy xps, energydispersive xray spectroscopy. A nonsequential pulsedmode deep reactive ion etching of silicon is reported that employs continuous etching and passivation based on sf 6 and h 2 gases. Rapier deep reactive ion etching system drie standard operating procedure revision. This method permits the fabrication of deep trenches with reduced surface roughness. Tilt free, high aspect etching with industry leading. Three step deep reactive ion etch for high density. Effects of deep reactive ion etching parameters on etching rate and.
Deep reactive ion etching drie is a type of reactive ion etching aimed at creating very deep, high aspect ratio structures. Deep dry etching of silica is used for patterning of waveguides for optoelectronic applications. A high etching rate is always a high priority, since it can save time and cost in the etching process and can enhance the possibility of mass production within this process. The fabrication of patternable silicon nanotips using deep. Control of trenching and surface roughness in deep reactive ion etched 4h and 6h sic glenn m.
Fua department of engineering, university of cambridge, 9 j. Control of trenching and surface roughness in deep. Deep reactive ion etching drie is used to create deep, steep sided features in silicon wafers with aspect ratios etch depthfeature width beyond 10. Rie is a type of dry etching which has different characteristics than wet etching. While deep reactive ion etching using an inductively coupled plasma icp source has proven to be a boon to the fabrication of siliconbased microelectromechanical systems, the process is highly. Polyimidedamagefree, cmoscompatible removal of polymer. It is designed to provide high aspect ratio etching using inductive coupled plasma icp. Deep reactive ion etching request pdf researchgate. The icp source generates a highdensity plasma due to inductive coupling between the rf antenna and plasma. Reactive ion etching rie deep reactive ion etching drie r. Deep reactive ion etching an overview sciencedirect topics. The plasma is generated under low pressure by an electromagnetic field.
Evans nasa glenn research center, 2 brookpark rd, cleveland, oh, 445 abstract an optimized deep reactive ion etching drie process for the fabrication of sic microstructures has been developed. The method combines dry oxygen plasma ashing and conventional photoresist wet stripping. Silicon drie systems deep reactive ion etching samco inc. The technique is developed and licensed by robert bosch gmbh 1 and relies on the repeated alternation of isotropic silicon etching and passivation steps to obtain anisotropic pro les. Shannona department of mechanical and industrial engineering, university of illinois at urbanachampaign. First, 5 h etching experiments using etching gases with 0%, 5%, 10% and 20% oxygen. Comparison is often made to anisotropic wet etching because sometimes drie and koh can both be used, and selection has to be reasoned. The bosch process is explained in detail as is cryogenic drie with details on the various etch masks for silicon. Reactive ion etching rie is a high resolution mechanism for etching materials using reactive gas discharges. In order to achieve feature sizes that cannot be obtained through conventional photolithography, nanobioengineers have reached for advanced manufacturing techniques, everything from xray lithography, deep reactiveion etching, and electronbeam lithography to scanningprobe lithography, twophoton polymerization, pulsed laser deposition, and focused ion beam. This study empirically investigates the influences of several parameters on surface morphology and etch rate in a highaspectratio silicon.
Etching enabled high aspect ratio complex geometry legolike silicon electronics pdf. Deep reactive ion etch, drie, bosch process, conditioning recipe, seasoning recipe 1. Pdf a three step deep reactive ion etch drie process is developed to etch. The sts deep reactive ion etch drie system uses sf6 for etching and c4f8 for passivation or deposition steps. Maximum achievable aspect ratio in deep reactive ion. Deep reactive ion etch drie and silicon direct bonding.
Drie system rie800ipb is a high performance inductively coupled plasma icp etching system that uses highdensity plasma to perform deep silicon etching required by mems and tsv applications. It was developed for microelectromechanical systems mems, which require these features, but is also used to excavate trenches for highdensity capacitors for dram and more recently for creating through. Our systems have the ability to be used both with cryo etch and bosch processes that can create deep penetration, steepsided holes and trenches in wafers with high aspect ratios. Fabrication of sharp silicon hollow microneedles by deepreactive. Highenergy ions from the plasma attack the wafer surface and react. There are three important parameters in deep reactive ion etching drie. Layout controlled onestep dry etch and release of mems using deep rie on soi wafer. This chapter also discusses the applications of drie such as free shape.
Ion bombardment removes the passivation layer from horizontal. Translation find a translation for deep reactive ion etched in other languages. While reactive ion etching of diamond has been reported previously, precision structuring of freestanding micromechanical components in single crystal diamond by deep reactive ion etching has hitherto remained elusive, related to limitations in the etch processes, such as the need of thick hard masks, micromasking effects, and limited etch rates. Deep reactiveion etching drie is a type of plasma etching which allows creation of. The passivation layer, as an important step for deep vertical etching of silicon, is feasible by hydrogen pulses in proper timeslots. Darling ee527 winter 20 the need for anisotropy for precise micromachining, it is highly desirable for the. Fabrication of sharp silicon hollow microneedles by deep. 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. Advanced deep reactiveion etching drie technology for. Related content fabrication of micro nano dualscale structures by improved deep reactive ion etching guangyi sun, tianle gao, xin zhao et al. Us20070015371a1 etching radical controlled gas chopped. A modified version of rie is deep reactiveion etching, used to excavate deep features.
Plasma etching techniques including rie, pe, icp, and drie. Request pdf deep reactive ion etching this chapter discusses the deep reactive ion etching in detail. We report on the use of electron cyclotron resonancereactive ion etching process for deep reactive ion etching of silica glass films using different fluorocarbons as etch gases. Nanomaster drie systems incorporate a planar icp source for high density plasma generation. While a standard rie process can be used, they are often inadequate so a couple of variations have been developed for specific applications. A method for removal of passivation polymer residues from deep reactive ionetching drie has been systematically investigated in this study. Pdf three step deep reactive ion etch for high density trench etching. A plasma creates ions, and neutral species that are drawn to a biased electrode. Grayscale lithography and deep reactive ion etching. Reactive ion etch equipment qualitative synergism of ion bombardment and chemical etching. The optimized process enables the etching of 4h and 6h sic to depths 100 microns with the required characteristics of 1 high rate 0. Plasma etching techniques are typically classed by the configuration of the electrodes. Samco was the first japanese semiconductor process equipment manufacturer to offer drie systems using the bosch process. This process is a twophase procedure comprising a passivation phase and an etch phase.
Deep reactive ion etch drie rogue valley microdevices. We used a homemade magnetically enhanced, inductively coupled plasma reactive ion etcher meicprie and electroplated nickel masks. Drie provides anisotropic selective silicon etching and is the only way to provide fast, highaspect ratio silicon micromachining with precise feature definition and etch profile control. Advanced deep reactiveion etching drie technology for hollow microneedles for transdermal blood sampling and drug delivery yufei liu a, pey fen eng a, owen james guy a, kerry roberts b, huma ashraf b, nick knight b a college of engineering, swansea university, singleton park, swansea sa2 8pp, uk b spts technologies limited, ringland way, newport, np18 2ta, uk. Anisotropic etching of silicon using deep reactive ion etching drie is among the key technologies for fabrication of microstructures for a wide range of applications. Thomson avenue, cambridge cb3 0fa, united kingdom and department of mechanical engineering, school of engineering and physical sciences, heriot watt university, edinburgh eh14 4as, united kingdom a. The bosch process the socalled bosch process lends itself to the dry chemical etching of structures with steep sidewalls and a very high aspect ratio. Deepreactive ion etching enables highly anisotropic.
Much of todays deep silicon etching is accomplished by means of the bosch process. Deep reactive ion etching as a tool for nanostructure fabrication y. By adjusting the etching parameters such as plasma power. Etching systems drie deep reactive ion etching systems rie800ipb. Deep reactive ion etching of silica for planar lightwave. The method uses precisely controlled, alternated or chopped gas flow of the etching and deposition gas precursors to produce a controllable sidewall passivation capable. A novel nonsequential hydrogenpulsed deep reactive ion. Introduction deep reactive ion etching drie is a means of etching deep, high aspect ratio 30. It was developed for microelectromechanical systems mems, which require these features, but is also used to excavate trenches for highdensity capacitors for dram and more.
Maximum achievable aspect ratio in deep reactive ion etching of silicon due to aspect ratio dependent transport and the microloading effect junghoon yeom, yan wu, john c. Berkeley ee143 f2010 lecture 15 hard mask for etching. Effects of deep reactive ion etching parameters on etching. Deep reactive ion etching is enabled by equipment that can achieve high density of reactive species, and independent control of ion current and ion energy. A method for silicon micromachining techniques based on high aspect ratio reactive ion etching with gas chopping has been developed capable of producing essentially scallop free, smooth, sidewall surfaces. Drie processes are often based on the cyclic bosch process. Reactiveion etching rie is an etching technology used in microfabrication. This is accomplished in part by using a switched gas scheme that includes both a passivation and etch step, otherwise known as. Deep reactive ion etching introduction to microfabrication wiley. The combination of anisotropic and isotropic etching steps can be used to make free. An optimized deep reactive ion etching drie process for the fabrication of sic microstructures has been developed. Reactiveion etching article about reactiveion etching. Pdf we have developed a deep reactive ion etching of pyrex glass in sf 6 plasma. Samco provides silicon deep reactive ion etching drie systems for mems device fabrication and tsv viahole etching.
In the deposition step, a c4f8 layer is deposited while in the etching step, using ion assisted etching, the polymer is removed from the base of the. We used a homemade magnetically enhanced, inductively coupled plasma reactive ion etcher meicprie. With the addition of our spts 200mm pegasus ase drie, we now offer deep reactive ion etch drie, a technique used in advanced mems device fabrication. Approaches to minimize deep trench etching problems. Deep reactive ion etching drie is used to create deep, steep sided features in silicon wafers. Precision micromechanical components in single crystal. Deep reactiveion etching drie is a highly anisotropic etch process used to create deep penetration, steepsided holes and trenches in waferssubstrates, typically with high aspect ratios.
Deep reactive ion etching drie sop may 20 loading a sample and running a recipe 1 if the load lock is under vacuum click on vent and wait approximately 3 minutes for the chamber pressure to come up to. One major advantage to rie over other forms of etching is that the process can be designed to be highly anisotropic, allowing for. Deep reactiveion etching drie is a highly anisotropic etch process used to create deep. This chapter discusses reactive ion etching and deep reactive ion etching on wafers detailing the various equipment and reactor requirements for different applications. This is a cyclic process employing alternating etch and deposition chemistries. Various chemistries have been proposed, but the bosch process is the most common 22. Cryogenic deep reactive ion etching of silicon micro and nanostructures manuscript submitted 7. It is a highly controllable process that can process a wide variety of materials, including semiconductors, dielectrics and some metals. Formal training is required for all users prior to using the system. This chapter concentrates on silicon deep reactive ion etching drie processes, with some basic structures. In this article, we describe more than 100mmdeep reactive ion etching rie.