SINTEF movemems. a standard process for piezoelectric microsystems prototyping

Transcription

1 SINTEF movemems a standard process for piezoelectric microsystems prototyping Frode Tyholdt

2 Background Small and medium companies/ Universities have ideas for piezomems Difficult to make Need special tools and expertise Companies are looking for high volume solutions Prototyping Deposition Fabrication The market for piezomems is increasing rapidly. Main market drivers are: Ink-jet printers Ultrasonic tools A lot of other interesting devices are emerging piezomems accelerometers

3 piezomems competence centre The competence centre aims to act as contact point for interested parties and covers the whole production process for piezoelectric microsystems World-class piezoelectric thin films (PZT). e 31,f ~ -14 C/m 10 Hz Deposition process and tools for high-performance PZT thin films on silicon wafers Modelling software specifically for piezomems Modelling of device ideas and design assistance Evaluation of alternative processing routes Testing services and sophisticated testing equipment Manufacturing of prototypes Small scale production using 150 mm wafers Go to:

4 The movemems process movemems: a piezomems fabrication process w/ standard material parameters and procedures piezovolume: FP7 project to upscale movemems to high volumes (200 mm wafers) movemems design handbook movemems fabrication procedure PZT thin film deposition End piezomems product piezomems design tools Chemical solution deposition piezomems device fabrication (wafer level) Packaging and integration with electronics movemems process add-on For Coventorware

5 FP7 piezovolume ( ) PZT thin film deposition tools and procedures Design handbook Fabrication procedures VERMON Automated chemical solution deposition tool End piezomems product piezomems design tools In-line quality monitoring tools piezomems device fabrication procedures (wafer level) Packaging and integration with electronics Sputtering tool

6 piezomems modelling tool piezomems modelling tool 3D parametric library of standard piezomems components Integration with FEM software Material parameters included in process design kit (PDK) Process emulation (virtual manufacturing) 2D masks + description of fabrication process to create a voxel based 3D solid model. Virtual manufacturing Save Money by finding problems before fabrication. Enhance communication with highly detailed, interactive 3D models. Reduce time-to-market and gain a competitive advantage. Improve documentation and reduce document creation effort. Enhance Yield through improved design rules and defect modeling. Beam (in green): 400 x 50 um^2, 3um thick E=1.6e5 MPa, ν=0.2 Piezoelectric material (in magenta): 300 x 50 um^2, 1um thick Elastic-AnIso piezomems beam in Coventorware ARCHITECT. Virtual manufacturing of MEMS bond pads and comb drive. Courtesy X-FAB Semiconductor Foundries, AG.

7 Deposition tools CSD Adaptation of Solar-semi cluster coater tool Throughput goal 4 wafers/h µm (65 nm/min) on 200 mm wafers using new automatic CSD tool ( % uptime) Performance goal e 31,f ~ -14 C/m 2 Deposition cost /wafer µm due to consumables and equipment 43 % uptime 4-8 cent per 1x1 cm die using 200 mm wafers Solar-semi coating cluster Will be optimized for PZT but can also be used for other oxides 43 % uptime = 12h/day and 6d/week

8 Deposition tools sputtering New hot chuck sputtering add-on for Oerlikon s Clusterline 200 II for in-situ sputtering of PZT Throughput goal 3.6 wafers/h µm (60 nm/min) on 200 mm wafers ( % uptime) Performance goal e 31,f ~ -14 C/m 2 Deposition cost /wafer µm due to consumables and equipment 43 % uptime 4-8 cent per 1x1 cm die using 200 mm wafers Oerlikon Systems Clusterline 200 II Hot chuck during sputtering 43 % uptime = 12h/day and 6d/week

9 In-line quality monitoring Indirect estimation of e 31,f from d 33,f and ε Needed resolution for thin films <10 pm Laser interferometry Accuracy Better 4 % of real e 31,f Throughput 10 wafers/h Automation of measurements through electrode mask layout Parameter/coefficient tracking aixacct double beam laser interferometer (aixdbli) Operations cost 4 /wafer due to equipment 43 % uptime aixplorer data management and analysis software

10 Device example fabricated by the movemems process

11 Chemical solution deposited PZT Deposition on 100 and 150 mm platinized wafers 200 mm in 2011 Seed layer: To obtain highly {100} oriented PZT [1] Deposited by CSD [2] PZT: Morphotropic composition; PbZr 0.53 Ti 0.47 O 3 Modified 2-methoxyethanol route [3,4] 2 µm standard thickness e 31,f ~ -14 C/m 10 Hz ε r ~ 1 khz Intensity (counts) Intensity (counts) {100} 2µm PZT 53/47 Sol-gel seeded (111) Omega 2-theta (degrees) (degrees) PZT (100) rocking curve FWHM ~ 2.9 o {200} [1] N. Ledermann, P. Muralt, J. Baborowski, S. Gentil, K. Mukati, M. Cantoni, A. Seifert, and N. Setter, Sens. Actuators, A, A105, 162 (2003) [2] F. Tyholdt, F. Calame, K. Prume, W. Booij, H. Ræder, and P. Muralt, Journal of Electroceramics, 19, 311 (2007) [3] Gurkovich and Blum Ultrastruct. Process. Ceram., Glasses, Compos. (L. L. Hench and D. R. Ulrich, eds.), Wiley. NY, 1984, p. 152] [4] K. D. Budd, S. K. Dey, and D. A. Payne, British Ceramic Proceedings, 36, 107 (1985)

12 1600 Characterization ε r good quality indicator ε r ε r 800 Mean ε r = 1204 Std. dev = mm wafers with 2 µm PZT 5-10 mm 2 capacitors with regular separation. (Cr/Au top electrodes) Electric -2 field 0(kV/cm) Mean ε r = 1199 Std. dev = 10 Mean ε r = 1215 Std. dev = 12 Position ε r ~1200 with a variation of ~1% Measured with aixacct ε r Mean ε r = 1196 Std. dev = 12 TF2000 analyzer Position

13 Fatigue tests bipolar fatigue cycles ( ok) +/- 25 V fatigue signal 5 khz cycling frequency Before Development of remanent polarisation through the fatigue test After

14 The movemems process Electroceramics XII Trondheim June th 2010

15 Multi project piezomems wafer Accelerometers Microfluid pumps PIMPs

16 16 Electroceramics XII Trondheim June th 2010 The PiMP Piezo-Electric Micro-Piston Fabrication Spin-coat PZT Structure top electrode Structure device layer Structure backside to form membrane T. Bakke, A. Vogl, O. Żero, F. Tyholdt, I-R. Johansen and D. Wang, J. Micromech. Microeng. 20 (2010)

17 17 Electroceramics XII Trondheim June th 2010 PiMP my MEMS... IR filter Fabry Perot interferometer Mirror FTIR spectrometer

18 Fabry Perot Interferometer SOI/ PZT Si Tunable IR filter centre deflection (µm) outer ring - unpoled inner ring - unpoled outer ring - poled inner ring - poled actuation voltage (V) T. Bakke, A. Vogl, O. Żero, F. Tyholdt, I-R. Johansen and D. Wang, J. Micromech. Microeng. 20 (2010)

19 19 Electroceramics XII Trondheim June th 2010 Simulations Multilayer analytical model for PZT actuators agrees well with measurements Nonlinear behavior captured by finite element analysis using Comsol multiphysics Vertical deflection (µm) 5,0 4,5 4,0 3,5 3,0 2,5 2,0 1,5 1,0 0,5 Measured FEM Analytical z 0, Actuation voltage (V) multi-layered structure r R 2 R 1 neutral plane Si R in R out z p M 1 M 2 Au electrode PZT Pt electrode SiO 2 T. Bakke, A. Vogl, O. Żero, F. Tyholdt, I-R. Johansen and D. Wang, J. Micromech. Microeng. 20 (2010)

20 Double ring design 6 4 Outerring actuated Deflection (µm) Inner ring actuated Actuation voltage (V) -4-6

21 Temporal response Deflection (µm) Measured response to a square wave actuation signal Resonance frequency of 9.8kHz ,0 0,1 0,2 0,3 0,4 0,5 Time (ms)

22 Pure piston actuation 0V 20V

23 Mirror planarity V 20V Height (nm) ,5 1 1,5 2 Distance (mm) Uncoated surface: ~15 nm deformation of a 2 mm dia. mirror (<λ/40) 380µm thick mirror plate form a strong base for coatings T. Bakke, A. Vogl, O. Żero, F. Tyholdt, I-R. Johansen and D. Wang, J. Micromech. Microeng. 20 (2010)

24 Conclusions SINTEF movemems is a standard procedure for making piezomems Design and fabrication rules Design and modelling add-on for Coventorware (Coventor) High volume capability will be added through FP7 piezovolume ( ) Improving the Coventor software Sputtering/CSD tools (Oerlikon/Solar-semi) In-line quality monitoring tool for piezo thin films (aixacct) The piezoelectric Micro-piston is a very promising platform for micro IR filters and FTIR spectrometers

25 Acknowledgements EU FP7 for granting the piezovolume project Thank you!