Wafer Thinning Solution for Wafer-Level-Capped MEMS Devices

2006 ◽  
Author(s):  
E.S. Lacsamana ◽  
M.G. Mena ◽  
R.M. Navarro ◽  
N. Kuan ◽  
T.R. Spooner
Keyword(s):  
Mems Devices ◽  
Wafer Level ◽  
Wafer Thinning

An all-silicon process platfom for wafer-level vacuum packaged MEMS devices

2021 ◽  
pp. 1-1
Author(s):  
Mustafa Mert Torunbalci ◽  
Hasan Dogan Gavcar ◽  
Ferhat Yesil ◽  
Said Emre Alper ◽  
Tayfun Akin
Keyword(s):  
Mems Devices ◽  
Wafer Level

Wafer Level Micropackaging of MEMS Devices Using Thin Film Anodic Bonding

2002 ◽  
Vol 729 ◽  
Author(s):  
Lauren E. S. Rohwer ◽  
Andrew D. Oliver ◽  
Melissa V. Collins
Keyword(s):  
Shear Strength ◽  
Test Sample ◽  
Anodic Bonding ◽  
Mems Devices ◽  
Wafer Level ◽  
Thermal Actuators ◽  
Wafer Level Packaging ◽  
Hermetic Seal ◽  
Leak Testing ◽  
Before And After

AbstractA wafer level packaging technique that involves anodic bonding of Pyrex wafers to released surface micromachined wafers is demonstrated. Besides providing a hermetic seal, this technique allows full wafer release, provides protection during die separation, and offers the possibility of integration with optoelectronic devices. Anodic bonding was performed under applied voltages up to 1000 V, and temperatures ranging from 280 to 400°C under vacuum (10-4Torr). The quality of the bonded interfaces was evaluated using shear strength testing and leak testing. The shear strength of Pyrex-to-polysilicon and aluminum bonds was ∼10-15 MPa. The functionality of surface micromachined polysilicon devices was tested before and after anodic bonding. 100% of thermal actuators, 94% of torsional ratcheting actuators, and 70% of microengines functioned after bonding. The 70% yield was calculated from a test sample of 25 devices.

Microsensors, MEMS and NEMS Based Complex Adaptive Smart Devices and Systems

2001 ◽  
Author(s):  
Vijay K. Varadan
Keyword(s):  
Self Assembly ◽  
Communication Systems ◽  
Microelectromechanical Systems ◽  
System Level ◽  
Smart Devices ◽  
Mems Devices ◽  
Wafer Level ◽  
Sensors And Actuators ◽  
Complex Adaptive ◽  
Microelectronics Industry

Abstract The microelectronics industry has seen explosive growth during the last thirty years. Extremely large markets for logic and memory devices have driven the development of new materials, and technologies for the fabrication of even more complex devices with features sizes now down at the sub micron level. Recent interest has arisen in employing these materials, tools and technologies for the fabrication of miniature sensors and actuators and their integration with electronic circuits to produce smart devices and MicroElectroMechanical Systems (MEMS). This effort offers the promise of: 1. Increasing the performance and manufacturability of both sensors and actuators by exploiting new batch fabrication processes developed for the IC and microelectronics industry. Examples include micro stereo lithographic and micro molding techniques. 2. Developing novel classes of materials and mechanical structures not possible previously, such as diamond like carbon, silicon carbide and carbon nanotubes, micro-turbines and micro-engines. 3. Development of technologies for the system level and wafer level integration of micro components at the nanometer precision, such as self-assembly techniques and robotic manipulation. 4. Development of control and communication systems for MEMS devices, such as optical and RF wireless, and power delivery systems.

Characterization of Wafer Level Metal Thermo-Compression Bonding

2010 ◽  
Vol 2010 (DPC) ◽  
pp. 002326-002360
Author(s):  
Erkan Cakmak ◽  
Bioh Kim ◽  
Viorel Dragoi
Keyword(s):  
Surface Treatment ◽  
Metal Surface ◽  
Bonding Temperature ◽  
Transient Liquid Phase ◽  
Bonding Process ◽  
Bending Test ◽  
Strength Analysis ◽  
Mems Devices ◽  
Wafer Level ◽  
Bond Quality

The process of wafer-level bonding is being successfully used to form MEMS devices. Wafer level bonding may be realized by different methods such as thermo compression, transient liquid phase, anodic, glass frit, or polymer bonding. These methods have different requirements and the choice of wafer level bonding method is defined by the application type. Metal TCB has a wide variety of applications with materials of choice including Au, Cu and Al. 3D electrical connections are created by the use of Cu-Cu TCB; while CMOS MEMS devices may be realized by Al-Al TCB. In this study the wafer level bonding process of Cu-Cu and Al-Al TCB are characterized. The effects and significance of various bonding process parameters and surface treatment methods are reported on the final bond interfaces integrity and strength. Analysis methods include SAM, SEM, AFM, and four point bending test. Al-Al TCB samples were investigated on the interfacial adhesion energy and bond quality. IAE and bond quality were found to be positively correlated with bonding temperature. A bonding temperature of 500 °C or greater is necessary to obtain bond strengths of 8–10 J/m2. A positive relation between IAE and bonding temperature was observed for Cu-Cu TCB. IAE's of greater then 10 J/m2 were obtained on bonded samples that do not show a post bond residual seam on the bonding interface. An acid based pre treatment was shown to impact the surface properties of the initial metal surface hence affecting the IAE. Post bond annealing processes showed the most significant impact on the IAE of the Cu-Cu TCB system. To obtain comparable IAE values the Al-Al TCB method requires a higher bonding temperature. However the Cu-Cu TCB is sensitive to the initial metal surface condition and requires surface treatment processes prior to bonding to obtain high quality bonding results.

Thin Film Packaging for Vacuum MEMS Encapsulation: A Study on Outgassing Phenomenon

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 002428-002482
Author(s):  
D. Saint-Patrice ◽  
J. L. Pornin ◽  
B. Savornin ◽  
G. Rodriguez ◽  
S. Danthon ◽  
...  
Keyword(s):  
Thin Film ◽  
Ion Beam ◽  
High Vacuum ◽  
Chip Thickness ◽  
Process Conditions ◽  
Mems Devices ◽  
Wafer Level ◽  
Working Pressure ◽  
Baking Process ◽  
Sealing Materials

Most of the time, MEMS devices require hermetic encapsulation for protection against atmosphere, moisture, particles and standard back-end manufacturing technologies. In the last few years, Wafer Level Packaging (WLP) is moving toward developments on Thin Film Packaging (TFP) in order to save footprint, to reduce chip thickness and packaging costs. In the specific case of high-vacuum MEMS encapsulation (gyro, compass), long term pressure stability is required. As the final performances of these kinds of devices are strongly dependent on the working pressure, using TFP for MEMS encapsulation with controlled vacuum becomes more challenging due to very small cavity volumes. It is then necessary to understand the outgassing phenomenon that take place during TFP encapsulation in order to reduce it. In this paper, our latest developments on thin film packaging technology are presented. Outgassing from materials used in TFP and MEMS devices become key parameters to decrease the pressure inside the package and to improve the reliability. In a first part, pressure and Residual Gas Analysis (RGA) of typical TFP and typical MEMS materials are measured under different time / temperature baking processes. Measurements show that material outgassing mainly comes from H2 and maximum pick appears in the beginning of the thermal process. Thanks to these characterizations, an optimized outgassing baking process in term of time and thermal budget is presented. By minimizing the internal outgassing, materials deposited by PVD sputtering can now be implemented as sealing materials for low pressure MEMS devices. In a second part, specific low temperature Al based materials which has been developed on equipment fully compatible with front-end fab is presented. Multi-layer materials like Ti / Al based materials are compared to our single Al based material to decrease the microstructure size and to improve the sealing performances. Scanning Electronic Microscopy (SEM) and Focused Ion Beam (FIB) cross section characterizations confirm that the grain sizes are highly impacted by sputtering process parameters and a compromise has to be done with MEMS outgassing. Finally, the most suitable outgassing baking process for the inside cavity materials and various Al-based sealing materials and stacks are performed for a MEMS compass device on 200 mm wafers. Pressure inside the cavity less than 10 mbar is obtained and the TFP yield is presented on each process conditions. These results are very promising and showed the capabilities of TFP for vacuum MEMS encapsulation applications despite very small volume cavity. Development of such technology is still under way in order to reach high vacuum level in the range of 10-1 to 10-3 mbar.

Wafer-Level Strength and Fracture Toughness Testing of Surface-Micromachined MEMS Devices

1999 ◽  
Vol 605 ◽  
Author(s):  
H. Kahn ◽  
N. Tayebi ◽  
R. Ballarini ◽  
R.L. Mullen ◽  
A.H. Heuer
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Microelectromechanical Systems ◽  
Reliability Prediction ◽  
Bend Strength ◽  
Mems Devices ◽  
Wafer Level ◽  
Toughness Testing ◽  
Loading Devices

AbstractDetermination of the mechanical properties of MEMS (microelectromechanical systems) materials is necessary for accurate device design and reliability prediction. This is most unambiguously performed using MEMS-fabricated test specimens and MEMS loading devices. We describe here a wafer-level technique for measuring the bend strength, fracture toughness, and tensile strength of MEMS materials. The bend strengths of surface-micromachined polysilicon, amorphous silicon, and polycrystalline 3C SiC are 5.1±1.0, 10.1±2.0, and 9.0±1.0 GPa, respectively. The fracture toughness of undoped and P-doped polysilicon is 1.2±0.2 MPa√m, and the tensile strength of polycrystalline 3C SiC is 3.2±1.2 GPa. These results include the first report of the mechanical strength of micromachined polycrystalline 3C SiC.

Effects of Packaging Induced Stress on MEMS Devices and Its Improvements

2006 ◽  
Vol 326-328 ◽  
pp. 529-532
Author(s):  
Sung Hoon Choa ◽  
Moon Chul Lee ◽  
Yong Chul Cho
Keyword(s):  
Silicon On Insulator ◽  
Anodic Bonding ◽  
Mems Devices ◽  
Wafer Level ◽  
Process Technology ◽  
Molding Compound ◽  
Mems Packaging ◽  
Induced Stress ◽  
Induced Structure ◽  
Glass Process

In MEMS, packaging induced stress or stress induced structure deformation becomes increasing concerns since it directly affects the performance of the device. The conventional MEMS SOI (silicon-on-insulator) gyroscope, packaged using the anodic bonding at the wafer level and EMC (epoxy molding compound) molding, has a deformation of MEMS structure caused by thermal expansion mismatch. Therefore we propose a packaged SiOG (Silicon On Glass) process technology and more robust spring design.

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