Cmp chemical mechanical planarization solutions for the integration of highk metal gate technologies. It is found that ceo2 is more effective to obtain smooth si3n4 balls than other abrasives, and extremely smooth si3n4 balls with surface ra 4nm were obtained after polishing. This is clearly demonstrated by diffusing boron into selected areas of a wafer and then observing those areas protrude during polishing. Purchase chemical mechanical polishing in silicon processing, volume 63 1st edition. Dual silicon layer for chemical mechanical polishing.
A typical transistor wiring process flow of the time is shown. Oxide cmp 2800amin metal cmp 3500amin cmp is a process of smoothing surfaces with the combination of chemical. Sep 22, 2003 rapid progress in recent ic fabrication industry has increased the demand of tight specification of nonuniformity nu and surface polishing in silicon wafer planarization. Ee143 f2010 lecture 17 university of california, berkeley. Chemicalmechanical polishing cmp is currently the most popular method for ic wafer planarization. Chemomechanical polishing cmp has been a common method to produce nanoscale surface finish of brittle wafers. Simultaneous temperature measurement of wafers in chemical. Oh fused quartz ideal for processing silicon wafers. In principle, cmp is a process of smoothing and planing surfaces with the combination of chemical and mechanical forces. On the chemomechanical polishing for nanoscale surface finish. Pdf chemical mechanical polishing in silicon processing, volume 63 semiconductors and semimetals vol 63 free epub, mobi, pdf ebooks download, ebook torrents download. Process optimization and integration for silicon oxide.
Chemical mechanical polishing cmp is one of the most essential. In the modern semiconductor manufacturing processes, chemical mechanical planarization cmp has attained important processing step because of its ability to provide global planarization. Chemical mechanical polishing in silicon processing volume 63 semiconductors and semimetals volume 63 hwa li, shin m. Cmp chemical mechanical planarization and polishing. An alternative to processing of optical silicon substrates is chemical mechanical polishing cmp. Cmp chemical mechanical planarization cabot microelectronics. In such methods, the silicon carbide surface is contacted with a cmp slurry composition that comprises i a liquid carrier and ii a plurality of particles having at least a soft surface portion, wherein the soft surface portion includes a.
Surfactant mediated passivation to achieve chemical mechanical polishing selectivity by kyoungho bu may 2007 chair. Chemical mechanical planarization or chemical mechanical polishing cmp is a process that can remove topography from silicon oxide, poly silicon and metal surfaces. Slurry compositions and chemically activated cmp methods for polishing a substrate having a silicon carbide surface using such slurries. The polishing action is partly mechanical and partly chemical.
Silicon substrates are used in optical components for infrared systems and mirror systems. Pdf lowdamage direct patterning of silicon oxide mask. In such methods, the silicon carbide surface is contacted with a cmp slurry composition that comprises i a liquid carrier and ii a plurality of particles having at least a soft surface portion, wherein the soft surface portion includes a transition metal. An example of polish parameters is given in copending provisional application no. In the case of cmp process, the indentation depth lies in the range of nanometer or subnanometer, huge hydrostatic pressure induced in the local deformation area which makes. It is used to planarize oxide, poly silicon or metal layers in order to prepare them for the following lithographic step, avoiding depth focus problems during. Our cmp facility is available for use on a daily, weekly, or monthly basis. The semiconductor device may be planarized using a chemical mechanical polishing cmp in which the amorphous silicon layer acts as a stop layer to prevent damage to the. Experimental investigation of material removal characteristics in. Research on mechanism of chemical mechanical polishing. It can be difficult to implement dfm rules during manual inductor design. Chemicalmechanicalpolishing cmp, first used as a planarization technology in the manufacture of multilevel metal interconnects for highdensity integrated circuits ic, is readily adapted as an enabling technology in microelectromechanical systems mems fabrication, particularly polysilicon surface micromachining.
In order to enable highk metal gate technology, new chemical mechanical planarization steps or slurries are needed to meet the stringent planarity or defect requirements for device performance. Background art the escalating demands for high density and performance. Lynn fuller, professor cmp page 2 rochester institute of technology microelectronic engineering cmp chemical mechanical planarization. Chemical mechanical polishing includes traditional polishing, eg. After several decades of development, it has become accepted worldwide as a mainstream process in the fabrication of planar film. Ultrarapid polishing of silicon carbide sic substrates. Metrics included thickness removed and within wafer nonuniformity of the thickness removed. Chemical mechanical polishing in silicon processing, volume. Silicon carbide stop layer in chemical mechanical polishing. However, the subsurface damage problem caused by hard abrasives and chemical waste problem of cmp have decreased the.
Thats why we recommend chemical mechanical planarization to remove the microdamage that can result from the backgrind process. The present invention relates generally to chemical mechanical polishing of substrates, and more particularly to polishing with fixedabrasive polishing pads. Polishing processes behind silicon wafer production wafer. Cmp chemical mechanical planarization and polishing equipment. Modeling of padwafer contact pressure distribution in. Chemical mechanical polishing in silicon processing volume. Dual silicon layer for chemical mechanical polishing planarization technical field the present invention relates to semiconductor devices and methods of manufacturing semiconductor devices. If the wafer is still factory sealed, a backside polish may be necessary for some applications.
It was found that a high boron concentration reduces the removal rate. Cmp has been a part of silicon technology for many years, since it was introduced as a necessary step for ob taining a smooth damagefree silicon wafer surface. Us6443811b1 ceria slurry solution for improved defect. Chemical mechanical polishing is more commonly known as cmp polishing. Chemical mechanical polishing in silicon processing, volume 63. Snider department of electrical engineering, university of notre dame, notre dame, indiana 46556. The present invention has particular applicability to doublegate devices. Controlled chemical mechanical polishing of polysilicon and silicon dioxide for singleelectron device vishwanath joshi,a alexei o.
Jan 25, 2016 ever wonder how silicon wafers get so thin. Using cmp, planar, smooth, and damagefree surface can be obtained. Jul 03, 2001 then chemical mechanical polishing cmp is used to polish step 170 the surface dielectric layer, stopping on the silicon carbide layer remaining over the metal layer. Damascene process and chemical mechanical planarization. We specialize in postfab processing silicon wafers and. Chemical mechanical polishing cmp cnf users cornell. Chemical mechanical polishing cmp technology, being the mainstream technique of acquiring global planarization and nanometer level surface, has already become an attractive research item. Controlled chemical mechanical polishing of polysilicon. Characterization of the chemicalmechanical polishing process based on nanoindentation measurement of dielectric films chiwen liu, a bautong dai, b chingfa yeh a. Wafer polishing silicon wafer polishing wafer polishing. What are the processes involved in polishing a coarse wafer into a usable and highgrade silicon wafer. Figure 1 illustrates the cmp process in which an oxide surface is planarized by rotating a wafer under pressure against a polishing pad in the presence of a silicabased alkaline slurry.
Integrated circuits are typically formed on substrates, particularly silicon wafers, by the sequential deposition of conductive, semiconductive or insulative layers. The foundries learned that by managing density they were able to reduce wafer thickness variations created during chemicalmechanical polishing cmp processes, so they introduced density design rule checks drc. Rapid progress in recent ic fabrication industry has increased the demand of tight specification of nonuniformity nu and surface polishing in silicon wafer planarization. After creating the transistors in the silicon, a dielectric typically silicon oxide was deposited. Chemicalmechanical polishing cmp processes for polysilicon were characterized using a noncontact capacitance probe metrology system. Studies on chemical mechanical polishing cmp for silicon nitride si3n4 balls with ceo2 abrasive carried to investigate the mechanism of chemomechanical action between silicon nitride and ceo2.
Polishing pressure is applied uniformly to the back side of the wafer via the hub, but the material removal is dictated by the wafer. Present and future role of chemical mechanical polishing in wafer. In an effort to improve the silicon carbide sic substrate surface, a new electrochemical mechanical polishing ecmp technique was developed. Highefficiency planarization method combining mechanical polishing and atmosphericpressure plasma etching for hardtomachine semiconductor substrates.
Chemical mechanical polishing with multiple polishing pads. Technical glass products fused quartz, with its combination of high purity and mechanical stability at high temperatures, is the ideal material used in the processing of silicon wafers. Chemical mechanical polishing of silicon carbide the high temperature integrated electronics and sensors hties team at the nasa lewis research center is developing silicon carbide sic as an enabling electronic technology for many aerospace applications. The wafer temperature in chemical mechanical polishing cmp of silicon dioxide layers was measured. Technical glass products uses only the highest grade. Chemical mechanical polishing in silicon processing. Materials science and engineering chemical mechanical polishing cmp is an indispensable technique in the microelectronics industry to achieve planarization and patterning of metal and dielectric layers. Willardson, 9780127521725, available at book depository with free delivery worldwide. In this work, the effect of dopants on chemical mechanical polishing of single crystalline silicon was investigated. The components perform various functions that intertwine.
Characterization of the chemicalmechanical polishing. Ee143 f2010 lecture 17 wafer is polished using a slurry containing silica abrasives 1090 nm particle size etching agents e. Highefficiency planarization method combining mechanical. Lowdamage direct patterning of silicon oxide mask by mechanical processing.
Chemical mechanical planarization of electronic materials. This work focused on the siterminated 4hsic 0001 substrates cut 8 offaxis toward. Chemical mechanical planarization solutions chemical mechanical planarization cmp is a polishing process, which utilizes a chemical slurry formulation and mechanical polishing process to remove unwanted conductive or dielectric materials on the silicon wafer, achieving a nearperfect flat and smooth surface upon which layers of integrated circuitry are built. Chemical mechanical planarization for microelectronics applications. Chemical mechanical polishing for fabricating patterned w. In a cmp process, a rotating wafer is pressed against a rotating polishing pad while slurry containing chemical. However, the subsurface damage problem caused by hard abrasives and. Polishing processes behind silicon wafer production.
Cmp is the planarization technique which is used for the removal of excess material, as left over from the previous processing steps. Chemical mechanical planarization cabot microelectronics. Then chemicalmechanical polishing cmp is used to polish step 170 the surface dielectric layer, stopping on the silicon carbide layer remaining over the metal layer. We also found that the decreasing rate of the peaktovalley value of the mesa structure obtained by cmppcvm combined processing was approximately seven times greater than that during mechanical polishing. Chemical mechanical polishing planarization typical process conditions pressure.
When working with thin silicon, keeping the wafer damagefree is a challenge. Fill has been around for many nodes, and was originally introduced to improve manufacturing results. This is the process where the top surface of a wafer is polished with a slurry containing an abrasive grit, suspended within reactive chemical agents. Fundamental studies on silicon dioxide chemical mechanical. Ultralargescale integrated ulsi circuits, with 108 or more devices on a chip, can now be fabricated on semiconductor substrates, or wafers, to reduce cost and to increase the performance of electronic products. Chemical mechanical polishing cmp is a technique which is frequently used in the fabrication of high quality lenses and mirrors and in the preparation of silicon wafers for integrated. Pdf experimental investigation of material removal.
Investigation of material removal mechanism of silicon wafer. It is found that ceo2 is more effective to obtain smooth si3n4 balls than other abrasives, and extremely smooth si3n4 balls with surface ra 4nm were. Mechanochemical polishing of silicon wafers, journal of. Chemical mechanical polishing in silicon processing volume 63 semiconductors and semimetals volume 63. Wafer polishing is available on virgin or reclaim silicon wafer substrates. Chemical mechanical polishing in silicon processing download bok. It is used to planarize oxide, poly silicon or metal layers in order to prepare them for the following lithographic step, avoiding depth focus problems during illumination of. Chemical mechanical planarization or cmp is a process used to planarize and remove material from a wafer surface. Chemical mechanical polishing cmp processes produce both global and local planarization through relatively simple and quick processing. Tricard, prime silicon and silicononinsulator soi wafer polishing with magnetorheological finishing mrf, accepted for publication. Electrochemical mechanical polishing of silicon carbide.
The chemical polishing is carried out with a mixture of hydrofluoric acid, nitric acid and acetic acid. What is chemical mechanical polishing or cmp polishing. By definition, cmp is a process whereby both chemical and mechanical actions complement each. Chemical mechanical polishing cmp, first used as a planarization technology in the manufacture of multilevel metal interconnects for highdensity integrated circuits ic, is readily adapted as an enabling technology in microelectromechanical systems mems fabrication, particularly polysilicon surface micromachining. Polishing of hardinert materials materials hardness knoop kgmm2 chemical action silicon carbide 2150 2900 inert quartz 820 porous silica sio 2 200500 gallium nitride 1580 1640 inert sapphire al 2 o 3 20002050 inert diamond 8000 0 inert polishing rate is slow when soft particles such as. Cmp chemical mechanical planarization papers case studies cmp polishing pad selected by leadingedge customer for its superior performance. An aqueous based ceria slurry system and method for chemical mechanical polishing of semiconductor wafers, the slurry comprising less than 5 wt % abrasive cerium oxide particles and up to about the critical micelle concentration of a cationic surfactant, absent other abrasives, in a neutral to alkaline ph solution is disclosed. As a result, we found that the convex parts of the mesa structure were preferentially removed and the surface of the sample was planarized. Controlled chemical mechanical polishing of polysilicon and. Pdf abrasive for chemical mechanical polishing researchgate. Studies on chemical mechanical polishing cmp for silicon nitride si3n4 balls with ceo2 abrasive carried to investigate the mechanism of chemo mechanical action between silicon nitride and ceo2. Study on the mechanism of silicon chemical mechanical. The modern day application of cmp process in the semiconductor industry was for polishing the surface raw silicon wafers to achieve a global flatness over raw. University of florida retrospective dissertation scanning project.
Effect of dopants on chemical mechanical polishing of silicon. Seeking to improve an already successful operation, a leading edge customer took into consideration its polishing process. It can, in a way, be thought of as a hybrid of chemical etching and free abrasive polishing. Virgin wafers under 300mm ship with a single side polish ssp on the front side, and an etched backside. Sti cmp process stop on silicon nitride is described in figure 6 3. Us9368367b2 chemical mechanical polishing of silicon. Investigation of material removal mechanism of silicon. Material product data sheet chromium oxide thermal spray. Semiconductors and semimetals volume 63 li, shin hwa on.
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