PEE-5740 "Tópicos de Fabricação de Microestruturas" Prof. Dr. Prof. Dr. Patrick Patrick B. B. Verdonck Verdonck
PEE-5740"Tópicos de Fabricação de Microestruturas"
Prof. Dr. Prof. Dr. Patrick Patrick B. B. VerdonckVerdonck
Programação Preliminar de aulas de PEE-57403o Período de 20043o Período de 2004(13/09) 1o aula: Introdução : Organização, conceitos básicos (13/09) 1o aula: Introdução : Organização, conceitos básicos –– Mario Gongora.Mario Gongora.(20/09) 2o aula: Química da corrosão úmida de silício :(20/09) 2o aula: Química da corrosão úmida de silício : MaluMalu + + Humber FurlanHumber Furlan(27/09) 3o aula: Materiais e processos utilizados na fabricação (27/09) 3o aula: Materiais e processos utilizados na fabricação de de microestruturas e demicroestruturas e de microsensoresmicrosensores, Conceitos de fabricação de microestruturas , Conceitos de fabricação de microestruturas em substratos e em superfície.em substratos e em superfície.(04/10) 4o aula: Materiais para fabricação de microestruturas em(04/10) 4o aula: Materiais para fabricação de microestruturas em superfícies : superfícies : Nilton Nilton MorimotoMorimoto(11/10) 5o aula: Técnicas de fabricação de microestruturas em su(11/10) 5o aula: Técnicas de fabricação de microestruturas em substratos, bstratos, (18/10) 6o aula: Técnicas de fabricação de microestruturas em su(18/10) 6o aula: Técnicas de fabricação de microestruturas em superfíciesperfícies(25/10) 7o aula: Simulação de microestruturas : (25/10) 7o aula: Simulação de microestruturas : Eliphas Eliphas W. SimõesW. Simões(08/11) 8o aula: Encapsulamento de microestruturas : Mario Gongo(08/11) 8o aula: Encapsulamento de microestruturas : Mario Gongora ra (22/11) 9o aula: Processo LIGA e outros processos avançados.(22/11) 9o aula: Processo LIGA e outros processos avançados.(29/11) 10o aula: Prova(29/11) 10o aula: Prova(06/12) 11o aula: Apresentação dos trabalhos(06/12) 11o aula: Apresentação dos trabalhos
Conceitos
Média= 0,2*(Nota de Trabalho)+0.2*(Nota Média= 0,2*(Nota de Trabalho)+0.2*(Nota de Listas)+0.6*(Nota de Prova)de Listas)+0.6*(Nota de Prova)
BIBLIOGRAFIA:1) M.1) M. MadouMadou,, FundamentalsFundamentals ofof MicrofabricationMicrofabrication, CRC, CRC PressPress (Boca(Boca RatonRaton -- NewNewYork) (1997)York) (1997)
2) J.N.2) J.N.Zemel andZemel and R.R.FurlanFurlan, Microfluidics, capítulo 12 do, Microfluidics, capítulo 12 do HandbookHandbook ofof Chemical Chemical and Biological Sensorsand Biological Sensors, editado por J.S., editado por J.S.SchulzSchulz, Inst. of, Inst. of Phys Publishing IncPhys Publishing Inc. . ((BristolBristol), (1996).), (1996).
3) Sensor3) Sensor technology and devicestechnology and devices, editado por, editado por Ljubisa RisticLjubisa Ristic,, Artech HouseArtech House(Boston), (1994). (Boston), (1994).
4)4) Semiconductor sensorsSemiconductor sensors, editado por S.M, editado por S.M SzeSze, J., J. WileyWiley ((NewNew York) (1994). York) (1994). 5)5) MicrosensorMicrosensor:: principles and applicationsprinciples and applications, editado por J.W., editado por J.W.GardnerGardner, J., J.WileyWiley((NewNew York) 1994. York) 1994.
6) M.6) M. ElwenspoekElwenspoek, H.V., H.V. JansenJansen "" Silicon MicromachiningSilicon Micromachining", Cambridge", CambridgeUniversity PressUniversity Press, (Cambridge) (1998), (Cambridge) (1998)
7) Y.X.Li, Plasma7) Y.X.Li, Plasma etchingetching forfor integrated siliconintegrated silicon sensorsensor appliationsappliations, Tese de , Tese de doutoramento, Delftdoutoramento, Delft UniversityUniversity,, The NetherlandsThe Netherlands, 1995. , 1995.
8)8) Micromachining and MicropackagingMicromachining and Micropackaging ofof TransducersTransducers, editado por C.D., editado por C.D. FungFung, , P.W.P.W. CheungCheung, W.H., W.H.KoKo,, andand D.G.Fleming,D.G.Fleming, Elsevier Science PublishersElsevier Science Publishers B.V., B.V., ((AmsterdamAmsterdam) (1985). ) (1985).
9) Artigos relacionados com a disciplina.9) Artigos relacionados com a disciplina.
MEMS evolved from the Microelectronics Revolution
IC Industry Timeline
1999
10 million transistors
1947
single transistor
1958
first IC
So what exactly is MEMS?
Micro-Electro-Mechanical Systems (MEMS) is the integration of mechanical elements, sensors, actuators, and electronics on a common substrate through the utilization of microfabricationtechnology or “microtechnology”.
General MEMS AdvantagesBatch fabricationBatch fabrication
Reduced costReduced cost
Reduced sizeReduced sizeIs everything better smaller?Is everything better smaller?
Reduced powerReduced powerHigh precisionHigh precisionNew capabilities?New capabilities?Improved performance?Improved performance?
MEMS ExamplesMEMS Examples
pressure sensorsaccelerometersflow sensorsinkjet printersdeformable mirror devicesgas sensorsmicromotorsmicrogearslab-on-a-chip systems
The The MicroTechnologyMicroTechnology/MEMS Tool Set/MEMS Tool Set
Cleanroom plusmicrofab processes
+
Micromachining Processes
Standard Integrated Circuit (IC) ProcessesStandard Integrated Circuit (IC) ProcessesIdentical to those used in IC fabricationIdentical to those used in IC fabricationGenerally used for surface Generally used for surface micromachiningmicromachining
Surface Surface MicromachiningMicromachiningAdditive processesAdditive processes
Bulk Bulk MicromachiningMicromachiningSubractive Subractive ProcessProcess
Dividing line can become very blurryDividing line can become very blurry
Standard IC ProcessesStandard IC Processes
1) Deposit/Grow Thin Films
• Sputtering• Evaporation• Thermal Oxidation• CVD• Spinning• Epitaxy
Standard IC ProcessesStandard IC Processes
2) Pattern Thin Films• Lithography• Etching Techniques (wet, dry, RIE)
Standard IC ProcessesStandard IC Processes
3) Introduce Dopants (to form electrically-active regions for diodes, transistors, etc.)
• Thermal Diffusion• Ion Implantation
MicromachiningMicromachining ProcessesProcesses
Bulk Micromachining
• wet vs dry• isotropic vs anisotropic• subtractive process
MicromachiningMicromachining ProcessesProcesses
Source: Madou
Bulk Micromachining
Source: MalufSource: Maluf
MicromachiningMicromachining ProcessesProcesses
• high density ICP plasma• high aspect ratio Si structures• cost: $500K
Deep Reactive Ion Etching (DRIE)
Source: LucasNova
Source: STS Source: AMMISource: STS
MicromachiningMicromachining ProcessesProcesses
Wafer-Level Bonding• glass-Si anodic bonding• Si-Si fusion bonding• eutectic bonding• low temp glass bonding
Source: Maluf Source: EV
MEMS ExamplesMEMS ExamplesPressure Sensor (conventional) Source: NovaSensor
0
10
20
30
40
50
60
0 20 40 60 80 100 120
Pressure (PSI)
Out
put V
olta
ge (m
V)
Source: UofL
MicromachiningMicromachining ProcessesProcesses
Surface Micromachining• additive process• structural & sacrificial layers
Source: Sandia
MicromachiningMicromachining ProcessesProcessesLIGA (lithographie, galvanoformung, abformtechnik)• uses x-ray lithography (PMMA), electrodeposition and molding to produce very high aspect ratio (>100) micro-structures up to 1000 um tall (1986)
Source: Madou Source: Kovacs
MicromachiningMicromachining ProcessesProcessesPoor Man’s LIGA• uses optical epoxy negative-resist (SU-8) developed by IBM to produce high aspect ratio micro-structures (1995)
UofL Micro-reaction wells: 150 um wide, 120 um tall, 50 um wall thickness
Source: Maluf
MEMS ExamplesMEMS Examples
Lab-on-a-Chip Systems• separation• dilution• mixing and dispensing• analysis
Source: Caliper
MEMS ExamplesMEMS Examples
Accelerometers
Sources: Analog Devices, Lucas NovaSensor, and EG&G IC Sensors
MEMS ExamplesMEMS Examples
Channels, Nozzles, Flow Structures, and Load Cells
Source: EG&G IC Sensors
Scaling in MEMSLinearLinear extrapolationextrapolation ofof lengthlength comescomes easyeasyto usto usWeWe areare quicklyquickly at aat a loss though when loss though when considering the implications that shrinkingconsidering the implications that shrinkingofof length has on surface arealength has on surface area to volumeto volumeratiosratios (S/V)(S/V) and on the relative strengthand on the relative strength ofofexternalexternal forces (forces (actuator mechanismsactuator mechanisms))Some Some examplesexamples ofof effectseffects of S/V:of S/V:
Both very large and very small mamalsBoth very large and very small mamals (i.e.(i.e.animals with constant bodyanimals with constant body T)T) have difficulty have difficulty survivingsurviving :i.e.:i.e. therethere areare few nichesfew niches forfor the large the large animals and thereanimals and there isis too much heat losstoo much heat loss for for small small animalsanimals ((heat lossheat loss ~ L~ L22 and heat generation and heat generation ((through eatingthrough eating) is ~ L) is ~ L33))------insects avoid this insects avoid this problem by being cold bloodedproblem by being cold bloodedCapillary tubes Capillary tubes (L(L33 vsvs. L. L11):): weight scalesweight scales as Las L33
and surface tensionand surface tension as Las L
Scaling LawsNature seemsNature seems to favorto favor smallsmall e.g. e.g. InsectsInsects areare very well adaptedvery well adapted::AsAs the scalethe scale of of structures structures decreases sodecreases so doesdoes the importance the importance of of phenomena that vary with the phenomena that vary with the largest powerlargest power ofof thethe linear linear dimensiondimension
––Insects walk on waterInsects walk on water ((surface surface tension supports their masstension supports their mass m)m)Insects jumps very farInsects jumps very far (E~(E~mh and mh and musclemuscle forfor that workthat work is ~m is ~m soso h is ah is aconstantconstant))Faster cooling and heating Faster cooling and heating ((cold cold bloodedblooded))Small thermal stressesSmall thermal stresses ((Small Biot Small Biot numbernumber i.e.i.e. little thermal little thermal stress)stress)
Scaling LawsA A Matrix formalismMatrix formalism is is used used to to describe the scaling describe the scaling
lawslaws. . This nomenclatureThis nomenclature shows ashows a numbernumber ofof differentdifferentforceforce lawslaws in ain a single equationsingle equation. In . In this notationthis notation,, the sizethe sizeofof the systemthe system isis represented byrepresented by aa single scale variablesingle scale variable, , L, L, which represents thewhich represents the linearlinear scalescale ofof the systemthe system. .
The choiceThe choice of of L for aL for a systemsystem is a bitis a bit arbitraryarbitrary.. TheThe L L could be the separation between the platescould be the separation between the plates of a of a capacitor,capacitor, oror itit could be the lengthcould be the length ofof one edgeone edge ofof thethecapacitor. capacitor. Once chosenOnce chosen,, howeverhowever, it is, it is assumed that all assumed that all dimensionsdimensions ofof the system the system areare equally scaled downequally scaled down ininsizesize as L isas L is decreaseddecreased ((isometric scalingisometric scaling). ).
Force Scaling LawsForFor exampleexample,, nominallynominally L= 1; if L isL= 1; if L is then changedthen changed to 0.1,to 0.1, all the all the dimensionsdimensions ofof the systemthe system areare decreased bydecreased by aa factorfactor of ten. of ten. AA numbernumber ofof differentdifferent cases arecases are shownshown inin one equationone equation. .
ForFor exampleexample::shows four cases forshows four cases for thethe forceforce lawlaw..The topThe top forceforce law scaleslaw scales as L,as L, next scalesnext scales as Las L squared orsquared or LL22
the nextthe next as Las L33,, and the bottomand the bottom as Las L44. .
The scalingThe scaling ofof thethe timetime requiredrequired to moveto move an object using thesean object using theseforces is forces is givengiven as:as:
The top elementThe top element inin equationequation 2 is L 2 is L 1.51.5.. ThisThis isis how thehow the time time scales when the scales when the force force scalesscales as Las L11. . The second element The second element shows shows thatthat tt scalesscales as Las L11 when the when the force force scales scales as Las L22.. The The third and forth elementthird and forth element showshow how thehow the time time scales when thescales when theforce force scalesscales as Las L33 andand LL44 respectivelyrespectively..