1、材料學中常用的分析方法instrumental analysis in materials science北京科技大學材料科學學院 唐偉忠 tel: 6233 2475 e-mail: 下載信箱：wztang_ 密碼：123456第八講ocused ion beam background 1beneath the surface, more is concealed: often, after you see microstructures on the surface, you have a desire to get into the buried underlying, otherwis

2、e you get little from the surface. but with sem or tem, you can see, and you cant touch. background 2a dedicated world to be explored in every detail: microelectronic components are getting smaller and smaller. and if you would like to see inside the complicated 3d structure of a device, you can not

3、 be sure whether you can do it by mechanically polishing and etching to obtain a useful sample. background 3a micro- and nanometer scaled world to create: rapidly, we are moving towards a micro- and nanometer world: micro- and nano-sensors, actuators and various kinds of mechanical and electrical ma

4、chines. when this is happening, we need dedicated machine tools.what is an fib? fib is just like a normal sem, but its e-gun is replaced by an ion gun. the advantage of fib lies in ions mass, orders of magnitude heavier than that of electrons.a ga+ ion beam columna sem, but its e-gun is replaced by

5、an ion gun, with 10nm ion beam spot size. commonly used hairpin source: a w filament and a coil are attached to a ceramic base and coated with liquid metal in a high vacuum. during operation, the metal is melted by resistive heating, allowing capillary flow of liquid metal to the tip where ions are

6、field evaporated and ionized by high voltages, forming a highly bright ion beam. （lmis） ion species available: ga in au au/ge alloy au/si alloy au/si/be alloy as/pd/b alloy as/pd alloy .（lmis） fib: liquid metal ion source(a)lmis socket with filament (c) filament filled with augesi alloyl. bischoff /

7、 ultramicroscopy 103 (2005) 5966 fib: liquid metal ion sourcegenerally, 5kv30kv acceleration voltage is used emission current as a function of voltagejem-9310 fib why a dual-beam fib?main elements of a dual-beam fibfib, sem, gas injection (for deposition and etching), detectors for electrons, ions a

8、nd x-ray q local flooding of reactive gases at the surface can either provide selective etching or selective deposition.q a low energy electron flood gun can be used to provide charge neutralization, and thus highly insulating samples may be imaged and milled without charging. e.s. sadki et al. / ph

9、ysica c 426431 (2005) 15471551ion beam induced or assisted depositiondeposition of metallic or insulating film is achieved from induced decomposition of a precursorion beam assisted deposition & etching in fibpt film could be deposited on sample surface by directing an organometallic compound precur

10、sor, (ch3)3ch3c5h5pt, dimethyl-methyl-cyclopentadienyl-pt, with ga+ ion beam scanning the area. q w deposition is possible from a w(co)6 precursor.q is also possible in i2 atmosphere. dual-beam fib capabilities “a microscope turned into a workbench”dual-beam fib capabilities: sem capabilities: se an

11、d be imaging edx, aes ebsd fib capabilities (analysis): iie (ion induced electron microscopy) imaging with similar resolutions as sem sim & sims (scanning ion microscope & secondary ion mass spectroscopy) ccm (channeling contrast imaging, “grain contrast”)a tool for materials characterization with 3

12、-10 nm resolutionfib capabilities (machining): sample processing ability (nano-patterning and machining) sputtering/ reactive etching ion induced deposition shallow ion implantation a tool for materials fabrication with 10 nm tolerance dual-beam fib capabilities a microscope turned into a workbencha

13、nalysismask repair nano-machiningq deposition: direct ultrafine deposition of metal or insulator (metals: w, au, fe; insulators: sio2, c) device modification nano-fabricationq materials characterization imaging, mapping in all sections and orientations imaging and mapping analysisfibfib se images of

14、 a au grid imaged with mn2+ beamiie: surface imaging with mn2+ fibiie: magnetic domain imaged with ga+ fibthe image shows magnetic domain pattern in a magnetic film. the image was taken by fib se imaging. the contrast is a consequence of deflection of electrons by local magnetic field near the surfa

15、ce. secondary electron image comparison spatial resolution of iie and sem images total positive and negative sims images of an al mesh. the negative ion image is much clearer than the positive one, because it contains not only secondary ions, but also secondary electrons.sims: surface imaging with f

16、ib sims image of a cracked mcp (micro-channel plate) obtained by using an au+ primary ion beam. the channel diameter is 10msims: surface imaging with fib the position of the line shows the position where a cross-sectioning will be made voltage contrast revealing open via positions in a circuitcross-

17、sectioning and analysisfim 樣品斷面分析的步驟證明了缺陷與基底材料的形貌密切相關，而薄膜的厚度則是均勻的顯示：不同厚度的薄膜中，不僅有柱狀晶、織構，且存在晶粒的異常長大after cutting the film with fib, the buckle geometry and the discontinuity revealing film stress relaxation. a: pt保護層, 其下面為厚度10微米的表面腐蝕層涂層磨損區斷面的 fib 觀察a failure feature within conductive lines: void forma

18、tionm .a . meyer et al . / microelectronic engineering 64 (2002) 375382 the time difference between the imaging is 2 hours. void formation results in a failure.void development at the cathode end of a line fib section of ink penetration into clay coated paperp.j. heard et al. / colloids and surfaces

19、 a: physicochem. eng. aspects 244 (2004) 6771 (a) low and (b) high magnification sem of fib-prepared ink printed paper. clay has been used to coat the paper.fib section of ink penetration into clay coated paperp.j. heard et al. / colloids and surfaces a: physicochem. eng. aspects 244 (2004) 6771(a)

20、low and (b) high magnification sem: significant ink penetration into the coating is visible, leading to waste of ink3d tomographical analysis（a）選擇區域，沉積pt 濺射保護層，切割（b）傾斜進行斷面觀察（c）重復a, b過程（d）使用計算機將2d圖象組合為3d圖象parallel 2d fib cross-sections indicate pile-up of material (arrow).為使相鄰晶粒顯示通道襯度，在兩個角度上進行了襯度觀察先傾

21、斜80度做截面切割，然后轉回30度，收集截面a的成分分布象。重復如上的過程，逐次獲得b, c截面的成分圖by ion beam image of tire debris, internal microstructure was observed, without any preparationsem of tire debris produced by normal wearm. milani et al. / materials characterization 284 52 (2004) 283288rosette crystal (a) may be cut by fib (b) and

22、 analyzedcrystallization study of vohpo40.5h2ol. omahony et al. / journal of catalysis 227 (2004) 270281with fib, successive slices of material (minimum thickness 50nm) can be removed. ebsd and edx analysis can construct 3d image of the original microstructurefib enables 3d-ebsd capabilityj. konrad

23、et al. / acta materialia 54 (2006) 13691380a precipitatemaps of average misorientation at two nearby sectionsfib enables 3d-ebsd capabilityj. konrad et al. / acta materialia 54 (2006) 136913803d view in vicinity of a laves-phase particle. the laves phase is colored blue. the warm-rolled fe3al phase

24、with small misorientation of less than 2.5 are colored goldfib enables 3d-ebsd capabilityj. konrad et al. / acta materialia 54 (2006) 13691380lift-outh-bar or trenchto prepare an h-bar tem sample with fib step 1 - obtain an aperture grid with a 1mm hole, cut away a portion of the grid. or orto prepa

25、re an h-bar tem sample with fib step 2 - create a specimen slice 1mm x 2.5mm, with the feature of interest positioned roughly in the center, and thin the slice to 60 m or less. to prepare an h-bar tem sample with fib step 3 - grid and slice come together by using a tem suitable adhesive. to prepare

26、an h-bar tem sample with fib step 4 ion milling the slice to electron transparency 100nmstep 1 locate the area of interest cross-sectional tem sample preparation automatic “lift-out” methodan area, indicated by the arrow, was marked by “x”s by fib. step 2 fib-deposit a protective pt layer pt was coa

27、ted on the surface to protect the area from ion damage.cross-sectional tem sample preparation automatic “lift-out” methodstep 3 mill two trenches from the both sides cross-sectional tem sample preparation automatic “lift-out” methodstep 4 thin the central region to electron transparencytrenches are

28、milled until electron transparent (less than 100nm).cross-sectional tem sample preparation automatic “lift-out” methodan u-shaped cut was made, then the sample is ready to be “lift out” by an electrostatic probe. step 5 perform frame cutscross-sectional tem sample preparation automatic “lift-out” me

29、thodstep 6 fib-mill to free membranecross-sectional tem sample preparation automatic “lift-out” methodse images showing the in situ lift-out procedurer.m. langford, c. clinton / micron 610 35 (2004) 607611 the fib plan-view lift-out techniquefib se image of grain boundary corrosion (black area is in

30、sulating). site-specific tem specimen preparation ofgrain boundary corrosion in ni-based alloysfib ion image of the region. oxygen enhanced ionization yield of the region making it appear white site-specific tem specimen preparation ofgrain boundary corrosion in ni-based alloys site-specific tem spe

31、cimen preparation ofgrain boundary corrosion in ni-based alloysfib si image after a thin protective layer of w is deposited. it serves also as a marker of the original surface. top and off-axis fib se views of the region milled free of the surrounding material. a small support holds the region in pl

32、ace until lift-out. site-specific tem specimen preparation ofgrain boundary corrosion in ni-based alloys site-specific tem specimen preparation ofgrain boundary corrosion in ni-based alloysfib se image of the region glued down on the carrier, ready for thinning to electron transparency. site-specifi

33、c tem specimen preparation ofgrain boundary corrosion in ni-based alloystem image (1,500x) of the final specimen mounted on the carrier. usually a particular region is important, and specimen must be cut so that a thin (1um) section contains the region of interest. a pt film is first deposited onto

34、the indent to protect the upper surface during subsequent milling. by etching around the interesting site, thin foils are available to tem observation.after etching through the structure, the cross section can be viewed by tilting the specimen in fib.the right image is a top view of the completed te

35、m foil which is electron transparent.tem image of the multilayer. the distortion of the surface layer is obvious.no plastic deformation occurs within the grains. intergranular cracks appear, c. degradation of tin coating under cyclic indentationj.m. cairney et al. / acta materialia 52 (2004) 3229323

36、7fib se shows cracks between columnar grains, x and few transgranular cracks, y. steps s appear at the base of the coating due to shearing of columnar grains. channelling contrast appears between different heavily deformed grains in the steel substrate, z. degradation of tin coating under cyclic ind

37、entationj.m. cairney et al. / acta materialia 52 (2004) 32293237(a) fib deposition of pt protective layer over the device (b) removal of bulk material on both sides of device areaa.c.k. chang et al. / thin solid films 496 (2006) 306 310(c) finely thinned and polished tem lamella (d) tem lamella cut

38、free from wafer, ready for lifting outa.c.k. chang et al. / thin solid films 496 (2006) 306 310tem of if steel sample near fib fabricated portion with edx analysis: ga incorporationfib induced damages in metallic tem samplej. yu et al. / materials letters 60 (2006) 206209high magnification tem near

39、fib irradiated areafib induced damages in metallic tem samplej. yu et al. / materials letters 60 (2006) 206209new phase formationfib prepared specimen for observing sidewall-damaged layerfib induced damages in si/si pn junction specimenz. wang et al. / applied surface science 241 (2005) 82 8086low a

40、nd high magnification view of damaged a-si layersfib induced damages in si device specimenz. wang et al. / applied surface science 241 (2005) 82 8086thickness of a-si layers induced by 10 and 20kev ga+ fibfib induced damages in si device specimenz. wang et al. / applied surface science 241 (2005) 82

41、 8086ion beam induced cellular relief on ge and its temdamage of crystalline ge by fib millings. rubanov, p.r. munroe / micron 35 (2004) 549556cellular relief temmicro-machiningfib micromachining capabilities fib deposition and milling can produce features 200nm or lessby scanning the ion beam to st

42、imulate chemical reactions, a metal or insulating line can be easily drawn.w deposition can produce “drill bits” and other complex structures which is then fib machined to a final shape. fib micromachining capabilities an “afm tip” with aspect ratio larger than 50:1, machined to a point with a radiu

43、s of curvature less than 40 nm. fib micromachining capabilities si fib micromachining a micromachinea si accelerometer is produced by conventional etching, then an angled cut is made by fib because conventional etching acts normally to the substrate and because the cut is very deep. fabrication of o

44、rganized arrays of quantum dotsschematic of ga+ ion beam etching into si3n4 mask j. gierak et al. / microelectronic engineering 7374 (2004) 610614gan dotsfabrication of organized arrays of quantum dotsthen gan dots were selectively epitaxially grown on si3n4 masked aln/sic by fib. j. gierak et al. /

45、 microelectronic engineering 7374 (2004) 610614 sinxgansem imagetem imagefib-fabricated sinx/au bimorph cantileverj. teng, p.d. prewett / sensors and actuators a 123124 (2005) 6086135 m long and 0.7 m wide, attached to a pt nano heater (databar=15 m). when heated, deflection will occur.pt heatercant

46、ileversub-micron intrinsic josephson junctioncritical current of a dc squid will oscillate when weak magnetic field changess.-j. kim et al. / physica c 412414 (2004) 14011405scanning ion-beam microscopy of sub-micron(0.12m2) intrinsic josephson junctionphysica c 426431 (2005) 14791483intrinsic josep

47、hson junction was cut from a ybco single crystal whisker, consisting of superconducting cuo2 layers and a block layer with thz oscillation frequencys.-j. kim et al. / physica c 412414 (2004) 1401140567% more efficient fiber-waveguide optical coupling lens could be made by fibf. schiappelli et al. /

48、microelectronic engineering 7374 (2004) 397404efficient fiber-to-waveguide coupling lensfiber-waveguide coupled optical signalsefficient fiber-to-waveguide coupling lenssem image of fib milled microlens (a) on top of the fiber tip and (b) its detailed view f. schiappelli et al. / microelectronic eng

49、ineering 7374 (2004) 397404fib machined probes for electric force microscopysketch of pt modified afm tip and fib fabricated and a pt coated electric conductive spm tipc. menozzi et al. / ultramicroscopy 104 (2005) 220225single-edge-notched tension specimen for fracture toughness measurementx. li et

50、 al. / sensors and actuators a 117 (2005) 143150single-edge-notched tension specimen for fracture toughness measurementx. li et al. / sensors and actuators a 117 (2005) 143150fib could introduce tiny notch to samples in any orientationslaser cutfib cutiie image of magnetic patterns microcircuit modi

51、fication成象加工制樣沉積using fib, viewing, cross sectioning, cutting of connections, deposition of conducting wires are all possibleschematic of device modificationa: fib cut to metal 1 b: fib via to metal 1 c: fib via to metal 2 d: fib strap joining vias device modificationa 0.15m device, with one bond pa

52、d isolated from the surrounding circuitry pad cut cutto test a correction before re-fabrication, metal wires can be exposed, cut, re-conected, and si02 insulated, over distances from m to mm. thus an ic can be prototyped in hours.device modificationdevice modificationa device modified by connecting

53、metal 3 to metal 1 through a 0.8 m wide hole filled with w. metal 3 metal 1 wmicrocircuit design errorsan error in circuit design have serious effects. correcting faults can take weeks.fib offer an alternative in repairing chips in hours.then, fib and a suitable gas is directed onto the fault, and w

54、, pt or sio2 may be deposited. also cuts may be made into the samples. modifications made to a microchip. 圖左下部是it may be used to make devices in a non-standard wayas+ implantation and a.j. de marco, j. melngailis / solid-state electronics 48 (2004) 18331836sem imagesem of structure with w electrodes

55、 connected by al pads but separated by siox layerm. prestigiacomo et al. / microelectronic engineering 76 (2004) 175181w electrodeal pad siox layerin fib, channeling contrast is more than four times as intense as that produced by backscattered electrons in the sem, and results in spectacular grain c

56、ontrast. fib can minimize artifacts of mechanical preparation, as in this case an electrode consisting of ni and ni(oh)2 powders in (inset: overall view of sectioning).iie image reveals grain structure and porosity difficult to observe using traditional techniques. grain orientation contrast is very

57、 pronounced.fib is very useful in corrosion study due to . as secondary ion yields can increase by orders of magnitude in the presence of oxygen.a with particle reinforcement covers a zinc galvanizing layer with partially cracked fe-zn intermetallic layer.sectioning of a pipeline steel allows measur

58、ement of crack length and depth. study of cracking in a pipeline steel cross-section of a showing porous surface and layers of “color absorbing grains,” lying within the film. sem surface image of a defectcross sectional sem image of the defectcross sectional sim image of the defect fib exposed a se

59、rious problem: an air inclusion in the paint gradually expanded to form a large bubble under the surface. the potential of corrosion was enormous.defect analysis by fib of in surface paint on a car doorimage of a distortion caused by an particle. the arrows indicate how the cross-section with the fib was made. failure analysis included particles in iciie image of the cross-sectioned particle