1Final Exam reviewFinal exam: take-home part! List five things that can be done to improve this class. Bespecific; give much detail.! (You will be penalized only for insulting comments madefor no benefit; you will not be penalized for any insultingcomments which have merit.)! Number of points per response will be based on the valueof the comment.! Alternative: rewrite one of the labs. Include at least 5significant changes.! Due by email to Matt by 11 December at 1700.Final Exam reviewLab final! Chamber will be open with samples mounted at correct height! You get to choose detector(s) to insert! “Three samples” to image" Au/C" Polystyrene balls on glass" Three microscope slides (Choose one for EDS)! Uncoated! Carbon coated! Gold coated! High resolution image of Au/C (500kX).! Image 0.5 micron polystyrene balls at 50kX! Determine chemical composition of microscope slide.! All machine parameters will be set to the same value! NovaNano! Schedule 1.5 hours with Matt. (All but 3 in regular class time)2Final Exam reviewEverhard-ThornleyDetector(X, Y)CCDCameraSample locations on multi-sample holder SEM class final examAu/CPolystyreneOn glassCarbon-coated Microscope slideGold-coated Microscope slideUn-coated Microscope slideFinal Exam reviewLast lab report (ESEM)! 1-page summary of how to use the ESEM (newstuff) and what you learned from using the ESEM! Attach and reference images and lab notes, asusual! Due when you take the lab final.3Final Exam reviewFinal exam format! Bluebook (supplied)! 8.5x11 sheet of notes permitted (NOT open book)! Questions from lecture, text, quiz! Calculator not needed…! Sample questions follow for discussion\! Monday Dec 15th 1pm room EMCB 103Final Exam reviewNanotubes on AFM tipDescribe the problem here, andapproaches to avoid it.4Final Exam reviewThe squared marks here arefrom what?A very large file full of “junk”…“streaks” indicate what?Final Exam reviewDirty or charge-sensitivesamples: How do you avoidthis?(Au nanoparticles on Si; oxide field)5Final Exam reviewCause?Cure?Final Exam reviewThese are “spheres”. Whereare the shadows?6Final Exam reviewSimple two-level CMOS…Passivation (oxide on nitride)Final Exam reviewNot all defects are so easy…Deprocessed to Metal-2 layer(RIE depassivation)Liquid Crystal Hot Spot7Final Exam reviewContinue Chemical Deprocessing…IMO removed by BOEM2 removed chemicallyFinal Exam reviewDeprocessing…BPSG removed, poly+ contactsM1 removed / BPSG remains8Final Exam reviewDefect location (finally!)Wright etch of Si(decorates stacking faults)Removal of poly gate…Cause of square artifactFinal Exam reviewSE Emission (topography-sensitive)(Dark contrast)(“bright” contrast)9Final Exam reviewTopography-induced contrastContrast mechanisms…with localdifferentialcharging effectsFinal Exam review(A) Identify six physical processesthat simultaneously occur whenan energetic electron beamimpacts a material, giving rise toimaging opportunities.10Final Exam reviewQuestion 8 - SEM, cont’d(B) Explain what is meant by“Interaction Volume”Final Exam review(D) Define Secondary Electron YieldOriginal Source Unknown: Contained in AVS Short Course Notes “SEM”Question 8 - SEM11Final Exam reviewSchematic use of S.E. Yield (!)SE YieldVACC1(E) Draw a the representative shape of a typicalinsulating material(F) Identify the conditions under which the samplecan be imaged without charging effects takingplace. Why?Final Exam reviewSiSiO2poly-SiW/SiBPSG(A) Use the SE Yield concept to explain thecontrast-forming mechanism for this image:S.E. Yield = f(material, Vacc)12Final Exam reviewHoles over dielectricholes overungrounded metalwhere metal has beenpreviously subjectedto extended beamdwellHoles over metal(uncharged)1.5keV imaging during via etch inspect(patterned oxide over patterned metal)(D) Contrast mechanism?Final Exam reviewFrom the case study on ICdamage…(E) “ring” Contrast mechanism?13Final Exam reviewWhat technique should you use?F) You have been asked for arecommendation how to image thecrystal orientation of a nanowire (~10-80 nm diameter; 1-3 microns in length)in a cluster. Explain briefly.2 Pts.Final Exam review Explain the physical principle: why canEDX spectra be acquired at muchhigher spatial resolution in (S)TEMversus SEM? (assume same e-beamspot size)2 Pts.14Final Exam reviewSimple two-level CMOS…Passivation (oxide on nitride)Sample: Packaged (de-lidded) IC with all pinsgrounded.==> Explain the depth of beam penetration forthe following images and ID relative chargestate:Question 9 - SEM contrast mechanisms(context)Final Exam review(i)Question 9 - SEM contrast mechanisms, cont’d15Final Exam review(H)Question 9 - SEM contrast mechanisms, cont’dFinal Exam review(G)Question 9 - SEM contrast mechanisms, cont’d16Final Exam review(F)Question 9 - SEM contrast mechanisms, cont’dFinal Exam reviewFIB SE image of Blanket thin Al film(j)Question 9 - contrast mechanisms, cont’d17Final Exam reviewZeiss Orion: He Ion MicroscopeFor demonstration of the imageresolution of 0.24 Nanometers alinescan over the very sharp edge of anasbestos fiber on a thin holey carbonfoil is shown. The texture of the holeycarbon foil demonstrates the extremelyhigh surface sensitivity of the ORION®which equals or even exceeds thesurface sensitivity of an SEM operatedat 1kV and below.Final Exam reviewThe secret to the amazing resolving power of the helium ion beam starts with thesource tip. A finely sharpened needle is made even sharper through a proprietaryprocess that took years to develop. Individual atoms are stripped away from the sourceuntil an atomic pyramid is created with just three atoms at the very end of the sourcetip ﾐ a configuration called the "trimer". This repeatable process can be accomplishedin-situ.Once the trimer is formed, the tip is maintained under high vacuum andcryogenic temperatures with helium gas flowing over it. A high voltage is applied to theneedle to produce an extremely high electric field at its apex. The helium gas isattracted to the energized tip where it is ionized. With ionization happening in thevicinity of a single atom, the resulting ion beam appears to be emanating from a regionthat is less than an angstrom in size. This produces an extremely bright beam that canbe focused to an extraordinarily small probe