Failure of micron scale Single Crystal Silicon bars due to torsion developed by MEMS micro instruments

1998 ◽  
Vol 518 ◽  
Author(s):  
Taher Saif ◽  
N. C. MacDonald
Keyword(s):  
Single Crystal ◽  
Single Crystal Silicon ◽  
Theory Of Elasticity ◽  
Shear Stresses ◽  
Electrostatic Actuator ◽  
Crystal Silicon ◽  
Cross Sectional ◽  
Lever Arm ◽  
Spring Constants

AbstractWe present an experimental study on a single crystal silicon (SCS) bar subjected to pure torsion using MEMS micro instruments. The bar is in the form of a pillar, anchored at one end to the silicon substrate. It is attached to a lever arm at the other end. The pillar has a minimum cross sectional area at its mid height. The cross section coincides with the (100) plane of SCS. Torsion is generated by applying two equal forces on the lever arm on either side of the pillar. Two micro instruments apply the forces. Each consists of an electrostatic actuator and a component that calibrates it. The actuator generates high force (≈ 200 µN at 50 V) and is capable of developing large displacements (≈ 10 μm). Calibration involves determination of the force generated by the actuator at an applied voltage, as well as the linear and higher order spring constants of its springs. Each microinstrument is thus calibrated independently.With the application of forces by the two micro instruments, a torque is generated which twists the pillar. The angle of twist at different applied voltages are recorded using an angular scale. The corresponding torques are determined from the calibration parameters of the actuators. Torque is applied until the pillar fractures. Two such sample pillars, samples 1 and 2, are tested. There cross sectional areas are 1 and 2.25 µm2. We find that both the pillars behave linearly until failure. The stresses prior to fracture are evaluated based on anisotropic theory of elasticity. Samples 1 and 2 fail at shear stresses of 5.6 and 2.6 GPa respectively. The fracture surfaces seem to coincide with the (111) plane of SCS.

A study of 2 MeV oxygen implantation to form deeply buried SiO2 layers

1989 ◽  
Vol 4 (5) ◽  
pp. 1227-1232 ◽  
Author(s):  
J. J. Grob ◽  
A. Grob ◽  
P. Thevenin ◽  
P. Siffert ◽  
C. d'Anterroches ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystal Silicon ◽  
Single Step ◽  
Annealing Process ◽  
Dislocation Network ◽  
Crystal Silicon ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Distribution Moments ◽  
Best Fit

Oxygen ions were implanted into (100) oriented single crystal Si at energies in the range of 0.6 to 2 MeV at normal and oblique (60°) incidences. Oxygen concentration profiles were measured using the 16O(d, α)14N nuclear reaction for 900 keV deuterons. The experimentally measured oxygen distributions were subsequently fitted to the theoretical profiles calculated assuming the Pearson VI distribution. The distribution moments (Rp, ΔRp, ΔR⊥ skewness, and kurtosis) were deduced as the best fit parameters and compared to the computer simulation results (TRIM 87 and PRAL). Whatever the calculation method, the measured Rp and ΔRp values are close to those predicted by the theory. Deeply buried SiO2 layers were formed using a single step implantation and annealing process. A dose of 1.8 × 1018/cm2 of 2 MeV O+ was implanted into the Si substrate maintained at a temperature of 550 °C. The implanted samples were characterized using the Rutherford backscattering (RBS)/channeling technique and cross-sectional transmission electron microscopy (XTEM). The implanted samples were subsequently annealed at 1350 °C for 4 h in an Ar ambient. The annealing process results in creating a continuous SiO2 layer, 0.4 μm thick below a 1.6 μm thick top single crystal silicon overlayer. The buried SiO2 layer contains the well-known faceted Si inclusions. The density of dislocations within the top Si layer remains lower than the XTEM detection limit of 107/cm2. Between the Si overlayer and the buried SiO2 a layer of faceted longitudinal SiO2 precipitates is present. A localized dislocation network links the precipitates to the buried SiO2 layer.

Precision determination of the density of a single crystal silicon sphere and evaluation of the Avogadro constant

2001 ◽  
Vol 50 (2) ◽  
pp. 587-592 ◽  
Author(s):  
M.J. Kenny ◽  
A.J. Leistner ◽  
C.J. Walsh ◽  
K. Fen ◽  
W.J. Giardini ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Avogadro Constant ◽  
Precision Determination

Fabrication and evaluation of single-crystal silicon cantilevers with ultra-low spring constants

2005 ◽  
Vol 15 (11) ◽  
pp. 2179-2183 ◽  
Author(s):  
Dong-Weon Lee ◽  
Jung-Ho Kang ◽  
Urs Gysin ◽  
Simon Rast ◽  
Ernst Meyer ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Spring Constants

Microwave Activation of Dopants & Solid Phase Epitaxy in Silicon

2007 ◽  
Vol 989 ◽  
Author(s):  
Douglas C. Thompson ◽  
J. Decker ◽  
T. L. Alford ◽  
J. W. Mayer ◽  
N. David Theodore
Keyword(s):  
Single Crystal ◽  
Microwave Heating ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Single Crystal Silicon ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Microwave System

AbstractMicrowave heating is used to activate solid phase epitaxial re-growth of amorphous silicon layers on single crystal silicon substrates. Layers of single crystal silicon were made amorphous through ion implantation with varying doses of boron or arsenic. Microwave processing occurred inside a 2.45 GHz, 1300 W cavity applicator microwave system for time-durations of 1-120 minutes. Sample temperatures were monitored using optical pyrometery. Rutherford backscattering spectrometry, and cross-sectional transmission electron microscopy were used to monitor crystalline quality in as-implanted and annealed samples. Sheet resistance readings show dopant activation occurring in both boron and arsenic implanted samples. In samples with large doses of arsenic, the defects resulting from vacancies and/or micro cluster precipitates are seen in transmission electron micrographs. Materials properties are used to explain microwave heating of silicon and demonstrate that the damage created in the implantation process serves to enhance microwave absorption.

Synchrotron Topographic Studies of the Influence of Rapid Thermal Processing on Defect Structures in Single Crystal Silicon.

1990 ◽  
Vol 209 ◽  
Author(s):  
Michael Dudley ◽  
Franklin F.Y. Wang ◽  
Thomas Fanning ◽  
Georgios Tolis ◽  
Jun Wu ◽  
...  
Keyword(s):  
Single Crystal ◽  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Single Crystal Silicon ◽  
Dislocation Motion ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
Crystal Silicon ◽  
Transmission Geometry

ABSTRACTSynchrotron white beam X-ray diffraction topography in transmission geometry has been used to non-destructively investigate defect structures in silicon single crystal wafers, both prior and subsequent to a 60 second rapid thermal processing (RTP) treatment at 1050°C. Prior to RTP dislocations, precipitates and swirl defects were observed and characterized. Following RTP the following effects were observed: glide of individual dislocations and dislocation multiplication; and the enhancement of the strain field associated with the swirl defects. Precipitates appeared unaffected by RTP. This work shows that synchrotron topography is capable of non-destructively revealing significant dislocation motion induced by RTP under conditions were such motion is not thought to occur. This dislocation motion is likely to be detrimental to device performance. The technique enables determination of the conditions required to avoid such dislocation motion.

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