Pattern & device transfer processes

Transcription

1 Journée Trans GDR «Micronanomanipulation pour les micro et nano systèmes» Besançon, 11 Avril 2012 Pattern & device transfer processes A. Bosseboeuf 1*, G. Schelcher 1, V. Beix 1,2, S. Brault 2, S. Nazeer 1, F. Parrain 1, E. Dufour-Gergam 1,E. Martincic 1,J. Moulin 1, F. Hamouda 1, A. Aassime 1 1 Institut d Electronique Fondamentale UMR 8622, Université Paris Sud, Bât ORSAY Cedex 2 KFM Technology, Z.A. de Courtaboeuf 11 rue de Norvège Villebon sur Yvette * alain.bosseboeuf@u-psud.fr

2 Outline Applications of pattern/devices transfer The ideal transfer process Principle and physics of transfer processes Transfer processes developped at IEF Pattern/device transfer of inorganic materials by adhesion engineering Pattern/transfer on PDMS UV nanoimprint Lithography Conclusion and future works 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 2

3 Applications of transfer processes Donor wafer New composite substrates SOI-like substrates with buried cavities III-V on Si, SiC/Si, Ferroelectric on Si, Ge on Sapphire, GeOI, SGOI, etc Patterns with elaboration conditions incompatible with substrate wafer Transfer Thin film packaging Target wafer High T materials on thermally instable substrates Cristalline materials on non cristalline substrates Patterns on chemically incompatible materials Die, device and MEMS transfer Mixing of different technologies (hererogenous integration) III-V and Si CMOS & MEMS Polymer and Si or III-V Glass Ex: CMOS on glass (Bowers ECTC 2009) CMOS 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 3

4 The ideal transfer process Versatile : Any materials (High T, Low T, inorganic, organic, ) Any pattern size (micro, nano), thickness and shape (1D, 2D, 3D) Multiple transfer & superimposition of patterns with different sizes Applicable on any surface (flat, structured, curved, ) Simple, low cost, re-usable donor wafer, high yield One donor wafer several target wafers Selective pattern transfer Minimum interaction with target substrate Low T & thermal budget, minimum target surface preparation/exposure Accurate (self? ) alignement 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 4

5 film/pattern/device transfer processes Single transfer: direct printing Contact, alignment (& bonding) Donor wafer Donor wafer Target wafer Target wafer Pattern reversal (Top Down) (Release) Donor wafer Target wafer Double transfer (pick & place): transfer printing «Pick» wafer «Pick» wafer «Pick» wafer «Pick» wafer Donor wafer Donor wafer Target wafer Target wafer No pattern reversal (Top Top) 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 5

6 Release step control Donor or pick wafer Sacrificial layer/wafer etching Low fracture strength Low adhesion «Pick» wafer Target wafer High adhesion Donor wafer Wet or dry etching Mechanical loading Donor wafer Sacrificial layer Thermomechanical stress Peeling Lifting Pulling Sliding «Cleaving» T>Tamb 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 6

7 Release step control Anti-adhesive film Adhesion reduction CxFy, Carbon (IEF) Oxidation of Ni layer (C.T. Pan et al. 2004) SAM (Janggil Kim et al. 2005, Jen-Yi Chen et al. 2002, IEF) Pb-Sn solder dewetting (W.C. Welch 2005) Fracture strength reduction Theters or pillars (H. Onoe 2007, C.A. Bowers 2008, etc..) Porous material, H implantation, Etc.. Post-processing Thermal/N 2 -H 2 plasma (IEF) Wet etching Ozone, O2 plasma Laser heating (R. Guerre 2008) UV degradation (H. Kawata 2008) Thermomechanical stress, etc Adhesion promotion Pressure & temperature (wafer bonding) SAM (Janggil Kim et al. 2005) Laser heating (Chun-Hung Che 2007) Water drying (Byoung Lee et al. 2007) UV polymerization 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 7

8 Inorganic pattern/device transfer with CxFy anti-adhesive layer and BCB bonding Patterning on CxFy film BCB joint patterning Wafer bonding Pattern release attern to transfer CxFy film Si BCB film Teflon-like film grown by plasma polymerization in a C 4 F 8 plasma Water Contact Angle on C x F y layer 112 XPS Surface Energy : 11,3 mn.m -1 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 8

9 Water contact angle ( ) F/C ratio Stress (MPa) Control of CxFy anti-adhesive properties Adhesion control by plasma processing (processing and XPS at LGPPTS) Debonding stress Cu/Ti/CxFy (tensile test) 120 Water contact angle F/C ratio 1,8 1,6 4,0 3, ,4 3,0 80 1,2 1,0 2,5 2, ,8 0,6 0,4 0, N2/H2 (1:3) plasma treatment time (s) 1,5 1,0 0,5 0, WCA on fluorocarbon film ( ) Strong defluorination Grafting of Nitrogen and oxygen species 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 9

10 Control of CxFy anti-adhesive properties Adhesion control by thermal annealing (XPS at LGPPTS) Thermal stability analysis by mass spectrometry (Coll. LGPPTS) Thickness reduction above T~90C, Large desorption above 200 C 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 10

11 Film Packaging Transfer of electroplated Ni patterns 1mm Transfer of micromechanical structures 300 µm 1mm Blister test Bonding strength up to 40 bars Pattern transfer on Flexible & Glass substrates Thicknesses from 7µm down to 700nm Low deformation of transferred structures 3D stacked structures 100µm 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 11

12 Other transfers with CxFy anti-adhesive film and BCB adhesive bonding Ni MicroPirani pressure gages SEM image after wire bonding Thermal map Resistance versus Pressure Filament Au Wire-bonding 600 nm lines 500µm 1mm Electroplated Cu on Si Sputtered finemet (soft magnetic material) 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 12

13 Stress (GPa) Inorganic pattern/device transfer with Carbon anti-adhesive layer Transfer of high T materials: Anti-adhesion film = Magnetron sputtered C film- Water contact angle:80 Stress measurement from deflection of C coated Si beams (C Film thickness<20nm) -2,0 Dépôt 1500s Dépôt s -1,5-1,0-0,5 %C-C %C-0 %C=O 71 16,4 12,6 0,0 0,000 0,002 0,004 0,006 0,008 0,010 0,012 Pressure (mbar) 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 13

14 Inorganic pattern/device transfer with Carbon anti-adhesive layer 10 to 200µm Cu patterns on Si Good yield on 4 wafers (90%) Validated for Cu and Ni films annealed up to 500 C Remaining issues: low deposition rate, low adhesion tunability and high stress 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 14

15 Transfer of metallic patterns on PDMS with water soluble, thermally stable inorganic sacrificial layer (Patented) Sacrificial layer dissolution in water Lift-off or micromolding Si PDMS coating with CxFy anti-adhesive layer Alignment & PDMS to PDMS bonding Free standing microbjects after PDMS removal 500nm Al lines on PDMS Si wafers mechanical release 3 axis flexible tactile sensor array (See poster by Nazeer et al.) 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 15

16 UV NanoImprint Lithography PDMS stamp fabricated from a Si mold master coated with TMCS anti-adhesive film 165nm Au dots on Si AMONIL/PMMA Lift-off Imprinting (200mbar) & 365nm UV exposure 100nm Holes in Si PDMS stamp release Etching RIE etching 13/04/2012 A. Bosseboeuf, Institut d Electronique Fondamentale 16

17 Conclusion and future works Good versatility of CxFy +BCB transfer process but limited to low T Films (<250C) Two transfer processes compatible with high temperature patterns developped In progress Lower temperature transfer process (<180C) by using Au/In instead of BCB Developpement of a wafer mechanical debonding system Developpement of other mechanical adhesion testing tools (FPB, Blade test) Future works Tests of transfer of high temperature materials Other anti-adhesive films, other bonding technologies? Other applications 13/04/2012 Institut d Electronique Fondamentale 17

18 References Transfer with CxFy anti(adhesive layer Patent : S. Brault et al., n , February 2nd G. Schelcher et al., IEEE J. MEMS, vol. 20, pp. 1184, S. Brault et al, Microsys. Techno., vol. 16, pp. 1277, G. Schelcher et al., J. Electrochem. Soc., Vol. 158, Issue 5, pp. H545, G. Schelcher et al. Proc. Eurosensors XXIV, 2010 M. Couty et al., DTIP proceeding (to be published) Transfer on PDMS Patent: DI 0316 HAMOUDA et al. Patent : DI 0334 AASSIME et al. Nazeer et al. Proc. IEEE IMS3TW, p.1-5, 2010 Nazeer et al. 219th ECS meeting, 2011 Patent : DI 0334 AASSIME et al. UV nanoiimprint lithography F. Hamouda et al. Microelec. Eng Barbillon et al. Microelec. Eng., /04/2012 Institut d Electronique Fondamentale 18