WIXLIB

MEMs Unit Processes - MeasurementROCHESTER INSTITUTE OF TEHNOLOGYMICROELECTRONIC ENGINEERINGMicroelectromechanical Systems (MEMs)Unit Processes for MEMsMeasurementDr. Lynn FullerWebpage: http://people.rit.edu/lffeeeMicroelectronic EngineeringRochester Institute of Technology82 Lomb Memorial DriveRochester, NY 14623-5604Tel (585) 475-2035Fax (585) 475-5041Email: Lynn.Fuller@rit.eduDepartment webpage: http://www.microe.rit.eduRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn Fuller4-25-2012 mem meas.pptPage 1

MEMs Unit Processes - MeasurementOUTLINEVisual InspectionOptical MicroscopyElectron MicroscopyLinewidthThicknessEtch RateResistivity and Sheet ster Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 2

MEMs Unit Processes - MeasurementOPTICAL MICROSCOPYTV CameraFiltersApertureTri-nocular Eyepiece andCamera MountBright Field Dark FieldSelection mechanismObjective lenses, 5X,10X, 40X, 100XStagex-y stage movementCoaxial IlluminatorIlluminator forTransparent SamplesRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerFocus and heightmeasurement eachdivision is 1 µmPage 3

MEMs Unit Processes - MeasurementOPTICAL PICTURE OF ETCH PIT20% KOH 100 Si Etch - 16 Hrs. @ 72CRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 4

MEMs Unit Processes - MeasurementPHILLIPS SEMRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 5

MEMs Unit Processes - MeasurementSEM PICTURESThese SEM pictures showtypical profiles of aluminumover steps from the CVC601.Rochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 6

MEMs Unit Processes - MeasurementSCANNING TUNNELING MICROSCOPE (STM)ZY 100 Å GapSurfaceXIPiezoelectric Motors Scan Tip in X and Y, Electronicscontrol Z such that the Tunneling Current I is Constant.The Control Voltage for Z is a Measure of Surface TopologyRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 7

MEMs Unit Processes - MeasurementATOMIC FORCE MICROSCOPE (AFM)Rochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 8

MEMs Unit Processes - MeasurementATOMIC FORCE MICROSCOPE (AFM) StandardSharp ApexSlenderLongUsed in Contact mode CD Mode (Conical andFlared)Flared tip able tomeasure undercutsidewallsUsed in non-contactmodeRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 9

MEMs Unit Processes - MeasurementLINEWIDTH MEASUREMENTCalibrate the output device for the microscope for a known size object.Then display unknown device and determine size by comparing theunknown to the known size.A filar eyepiece is an eyepiece with a mechanical dial that moves ahairline across the field of view. The markings on the dial arecalibrated by measuring a known size object. Unknown size objectsare measured by positioning the hairline on one edge of the object,reading the dial and positioning the hairline on the other side of theobject and reading the difference. Then calculating the size knowingthe calibration. This technique is limited to objects small enough to fitwithin the field of view. For larger objects a calibrated traveling stagewith a fixed hairline within the eyepiece can be used. Newer systemsuse CCD camera pixel counting rather than a mechanical eyepiece.Rochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 10

MEMs Unit Processes - MeasurementLINEWIDTH MEASUREMENT SYSTEMRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 11

MEMs Unit Processes - MeasurementHEIGHT MEASUREMENT USING OPTICAL MICROSCOPEDial divisions are 0.001 inchunits equal to 25.4 µmaccuracy is about 1/2 divisionor 12.5 µm, this is good formeasuring thickness in the100’s of microns rangeRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerFocus andheightmeasurementeach divisionis 1 µmPage 12

MEMs Unit Processes - MeasurementHEIGHT MEASUREMENT USING OPTICAL MICROSCOPEPut object on the microscope and obtainan image then place the micrometerunder the stage as shown to measure theheight change as the focus knob is turnedUse the 100 x Objective Lens forsmallest depth of focusFocus on top of object and setmicrometer dial to zeroFocus on bottom of objectand read the height on themicrometer dial.Rochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 13

MEMs Unit Processes - MeasurementOPTICAL TECHNIQUES FOR HEIGHT ANDDISPLACEMENT3D Surface TopographyHeights 0.1 nm to 5 mmResolution 0.1 nmRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn Fullerhttp://www.veeco.comPage 14

MEMs Unit Processes - MeasurementRIT’s VEECO WYCO NT1100 OPTICAL PROFILOMETERUsed to measure RMS surface roughnessRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 15

MEMs Unit Processes - MeasurementVEECO DYNAMIC OPTICAL PROFILERRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 16

MEMs Unit Processes - MeasurementSURFACE ROUGHNESS DATABare Silicon Wafer 5nm RMSAluminum CVC 601 – 6800Å 15nm RMSRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 17

MEMs Unit Processes - MeasurementRIT’S OTHER WYCO HEIGHT MEASUREMENT TOOLRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 18

MEMs Unit Processes - MeasurementHEIGHT MEASUREMENT USING OPTICAL MICROSCOPE500 µm31 µm20% KOH Etch, @ 72 C, 10 Hrs.Rochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 19

MEMs Unit Processes - MeasurementTENCORE P2 LONG SCAN PROFILOMETERRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 20

MEMs Unit Processes - MeasurementSTYLUS SURFACE PROFILOMETER10ReadoutFilm Thickness1,000 Å Max 1,000,000 Å0StylusFilmRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 21

MEMs Unit Processes - MeasurementOXIDE THICKNESS COLOR CHARTThick anBrownDark Violet - Red VioletRoyal BlueBlueLight Blue - Metallic BlueMetallic - very light Yellow GreenLIght Gold or Yellow - Slightly MetallicGold with slight Yellow OrangeOrange - MelonRed VioletBlue - Violet BlueBlueBlueBlue - Blue GreenLight GreenGreen - Yellow GreenYellow GreenYellowLight OrangeCarnation PinkViolet RedRed VioletVioletBlue 90010000ColorBlueBlue GreenGreenYellow GreenGreenYellowBlueX other materials LightXoxide1.45/nOrange orYellow - Pinkother materialYel low -"Yel lowish "(at times app ears to b e Lt gray o r matelli c)Carnation PinkViolet Red"Bluish"(appears violet red, Blue Green, look s grayBlueish)Blue Green - Green"Yellowish"OrangeSalmonDull, LIght Red VioletVioletBlue VioletBlueBlueBlue GreenDull Yellow GreenYellow - "Yellowish"OrangeCarnation PinkNitrideThickness (Oxide Thickness)(Oxide Index/Nitride Index)Rochester Instituteof TechnologyMicroelectronic Eg.EngineeringYellow Nitride Thickness (2000)(1.46/2.00) 1460 April 25, 2012 Dr. Lynn FullerPage 22

MEMs Unit Processes - Measurement(REFLECTANCE SPECTROMETER)NANOSPEC THICKNESS MEASUREMENTINCIDENT WHITE LIGHT, THE INTENSITY OF THEREFLECTED LIGHT IS MEASURED VS WAVELENGTH3000 Å OXIDEMONOCHROMATOR& DETECTOR7000 Å OXIDEλWHITE LIGHT SOURCEOPTICSWAFERRochester Institute of TechnologyMicroelectronic EngineeringλOxide on SiliconNitrideNeg ResistPoly on 300-1200 OxNeg Resist on Ox 300-350Nitride on Oxide 300-3500Thin OxideThin NitridePolyimidePositive ResistPos Resist on Ox 500-15,000 April 25, 2012 Dr. Lynn FullerPage 23400-30,000 0-500100-500500-10,000500-40,0004,000-30,000

MEMs Unit Processes - MeasurementNANOSPEC FILM THICKNESS MEASUREMENT TOOLRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 24

MEMs Unit Processes - MeasurementTENCORE SPECROMAPRecord:MeanStd DeviationMinMaxNo of PointsRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 25

MEMs Unit Processes - MeasurementELLIPSOMETRYSURFACEQUARTER WAVEPLATEPOLARIZERLIGHTSOURCEANALYZERFILTER (blocke s out room light)e lliptic linearpolarizedlinear polarizednullPHOTODETECTORunpolarizedThe light source is unpolarized, upon traversing the polarizer the light be comes linearly polarized. Turning the polarizer adjuststhe az imuth of linearly polarized light with re spect to the fast axis of the quarter-wave plate in such a way as to vary the e llipticityof the light incident on the surface. This ellipticity is adjusted until it is just cancelled by the e llipticity introduced by the re flection.The re sult is again linearly polarized light. The analyzer polarizing prism is rotated until its axis of polarization is pe rpendicular tothe az imuth of the linearly polarized light, creating a null. Thus no light is transmitted to the dedector. The common technique isto fix the quarter-wave plate with fast axis at 45 to the plane of incidence, and to alternately move the polarizer and analyzer,continuously reducing the transmitted light until a null is reached. The re levant light parameters and Ψ are re adily calculatedfrom the instrument parameters (P, polarizer angle, Q, quarter-wave plate angle, and A, analyzer angle. Values for film thicknessand inde x of re fraction are found. Thickness values that correspond to these parameters re peat with multiples of the light sourcewave le ngth so the approximate thickness must be known.Rochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 26

MEMs Unit Processes - MeasurementELLIPSOMETERRudolph EllipsometerVariable Angle SpectroscopicEllipsometerRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 27

MEMs Unit Processes - MeasurementGROOVE and STAIN FIND Xj AFTERPRE DEPOSIT OR DRIVE-INGrooveDMNMNXj (N * M) / D(at RIT D 1.532 inch)After StainStaining Solution - 1 Vol part HF, 2 Vol part Nitric Acid, 12 Vol part Acetic AcidAfter mixing drop a penny in solution for about 10 sec. result in a light bluecolor. Safety Stain - (does not have HF) is available from Philtec InstrumentCo. Philadelphia, PA 19129-1651, (215) 848-4500, Signatone makes groove tooland wheels, (408)732-3280Rochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 28

MEMs Unit Processes - MeasurementTRAVELING STAGE MICROSCOPEExample: If M .003 inchesand N 0.025 inches, find xj.Xj (N * M) / D (0.025 * 0.003)/1.532 inch) 0.0000472 inch 1.20 µmPoly on Oxide on Silicon(no stain)Rochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 29

MEMs Unit Processes - MeasurementDEPTH WITH TRAVELING STAGE MICROSCOPEKOH etches silicon along the (111)crystal plane giving a 53 angle.100µmExample: the traveling stagemicroscope is used to measurethe 100 µm distance shown.The depth is calculated.Tan 53 depth/100µmdepth 133 µmRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 30

MEMs Unit Processes - MeasurementETCH STEPS IN OXIDE TO FIND ETCH RATE5000 ÅBARE SILICONRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 31

MEMs Unit Processes - MeasurementSTEP ETCH APPARATUSBUFFERED HFLower 1/4 inch every 45 secondsRochester Institute of TechnologyMicroelectronic Engineering April 25, 2012 Dr. Lynn FullerPage 32

MEMs Unit Processes - MeasurementGROOVE AND STAIN AND 4PTPROBE FIND SHEETRESISTANCE AND RESISTIVITY FOR A DIFFUSED LAYERGrooveAfter StainXj (N * M) / DDMNXjMNIVS4PT PROBEXjRochester Institute of TechnologyMicroelectronic EngineeringRhos V / I * π / ln 2 4.532 V/I ohms/squareRho Rhos Xj ohm-cm April 25, 2012 Dr. Lynn FullerPage 33