Laser-induced back-side etching with liquid and the solid hydrocarbon absorber films of different thicknesses

2017 ◽  
Vol 123 (4) ◽  
Author(s):  
M. Ehrhardt ◽  
P. Lorenz ◽  
P. Yunxiang ◽  
L. Bayer ◽  
B. Han ◽  
...  
Keyword(s):  
Author(s):  
M. H. Rhee ◽  
W. A. Coghlan

Silicon is believed to be an almost perfectly brittle material with cleavage occurring on {111} planes. In such a material at room temperature cleavage is expected to occur prior to any dislocation nucleation. This behavior suggests that cleavage fracture may be used to produce usable flat surfaces. Attempts to show this have failed. Such fractures produced in semiconductor silicon tend to occur on planes of variable orientation resulting in surfaces with a poor surface finish. In order to learn more about the mechanisms involved in fracture of silicon we began a HREM study of hardness indent induced fractures in thin samples of oxidized silicon.Samples of single crystal silicon were oxidized in air for 100 hours at 1000°C. Two pieces of this material were glued together and 500 μm thick cross-section samples were cut from the combined piece. The cross-section samples were indented using a Vicker's microhardness tester to produce cracks. The cracks in the samples were preserved by thinning from the back side using a combination of mechanical grinding and ion milling.


2019 ◽  
Author(s):  
Yan Wang ◽  
Sagar Udyavara ◽  
Matthew Neurock ◽  
C. Daniel Frisbie

<div> <div> <div> <p> </p><div> <div> <div> <p>Electrocatalytic activity for hydrogen evolution at monolayer MoS2 electrodes can be enhanced by the application of an electric field normal to the electrode plane. The electric field is produced by a gate electrode lying underneath the MoS2 and separated from it by a dielectric. Application of a voltage to the back-side gate electrode while sweeping the MoS2 electrochemical potential in a conventional manner in 0.5 M H2SO4 results in up to a 140-mV reduction in overpotential for hydrogen evolution at current densities of 50 mA/cm2. Tafel analysis indicates that the exchange current density is correspondingly improved by a factor of 4 to 0.1 mA/cm2 as gate voltage is increased. Density functional theory calculations support a mechanism in which the higher hydrogen evolution activity is caused by gate-induced electronic charge on Mo metal centers adjacent the S vacancies (the active sites), leading to enhanced Mo-H bond strengths. Overall, our findings indicate that the back-gated working electrode architecture is a convenient and versatile platform for investigating the connection between tunable electronic charge at active sites and overpotential for electrocatalytic processes on ultrathin electrode materials.</p></div></div></div><br><p></p></div></div></div>


Author(s):  
J.S. McMurray ◽  
C.M. Molella

Abstract Root cause for failure of 90 nm body contacted nFETs was identified using scanning capacitance microscopy (SCM) and scanning spreading resistance microscopy (SSRM). The failure mechanism was identified using both cross sectional imaging and imaging of the active silicon - buried oxide (BOX) interface in plan view. This is the first report of back-side plan view SCM and SSRM data for SOI devices. This unique plan view shows the root cause for the failure is an under doped link up region between the body contacts and the active channel of the device.


Author(s):  
K. Dickson ◽  
G. Lange ◽  
K. Erington ◽  
J. Ybarra

Abstract This paper describes the use of Electron Beam Absorbed Current (EBAC) mapping performed from the back side of the device as a means of locating metallization defects on flip chip 45nm SOI technology.


Author(s):  
Jamey Moss ◽  
Sam Subramanian ◽  
Vince Soorholtz ◽  
Michael Thomas ◽  
Mark Gerber ◽  
...  

Abstract Several hundred units were subjected to autoclave stress as part of the qualification of a new fast static RAM. Many units failed after autoclave stress, and these parts recovered after conventional depotting using nitric acid and a hot plate. Based on the recovery of the units, the failures were determined to be fuse-related because the nitric acid cleared the fuse cavities during depotting. Chemical analysis after thermally extracting the die from the package revealed an antimony-rich material in failing fuse cavities. Source of the antimony was linked to antimony trioxide added to the plastic package as a fire retardant. However, it was unclear whether the antimony-rich material caused the failure or if it was an artifact of thermal depotting. A new approach that did not thermally or chemically alter the fuse cavities was employed to identify the failing fuses. This approach used a combination of back-side grinding, dimpling, and back-side microprobing. The antimony-rich material found in the fuse cavity was confirmed using SEM and TEM-based EDS analysis, and it is believed to be a major contributing factor to fuse failures. However, it is unclear whether the short was caused by the antimony-rich material or by a reaction between that material and residual aluminum (oxide) left in the fuse cavity after the laser blows.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 397
Author(s):  
Yu-Chen Chang ◽  
Ying-Chung Chen ◽  
Bing-Rui Li ◽  
Wei-Che Shih ◽  
Jyun-Min Lin ◽  
...  

In this study, piezoelectric zinc oxide (ZnO) thin film was deposited on the Pt/Ti/SiNx/Si substrate to construct the FBAR device. The Pt/Ti multilayers were deposited on SiNx/Si as the bottom electrode and the Al thin film was deposited on the ZnO piezoelectric layer as the top electrode by a DC sputtering system. The ZnO thin film was deposited onto the Pt thin film by a radio frequency (RF) magnetron sputtering system. The cavity on back side for acoustic reflection of the FBAR device was achieved by KOH solution and reactive ion etching (RIE) processes. The crystalline structures and surface morphologies of the films were analyzed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The optimized as-deposited ZnO thin films with preferred (002)-orientation were obtained under the sputtering power of 80 W and sputtering pressure of 20 mTorr. The crystalline characteristics of ZnO thin films and the frequency responses of the FBAR devices can be improved by using the rapid thermal annealing (RTA) process. The optimized annealing temperature and annealing time are 400 °C and 10 min, respectively. Finally, the FBAR devices with structure of Al/ZnO/Pt/Ti/SiNx/Si were fabricated. The frequency responses showed that the return loss of the FBAR device with RTA annealing was improved from −24.07 to −34.66 dB, and the electromechanical coupling coefficient (kt2) was improved from 1.73% to 3.02% with the resonance frequency of around 3.4 GHz.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4097
Author(s):  
Hee-Dong Jeong ◽  
Seong-Won Moon ◽  
Seung-Yeol Lee

Diffraction is a fundamental phenomenon that reveals the wave nature of light. When a plane wave is transmitted or reflected from a grating or other periodic structures, diffracted light waves propagate at several angles that are specified by the period of the given structure. When the optical period is shorter than the wavelength, constructive interference of diffracted light rays from the subwavelength-scale grating forms a uniform plane wave. Many studies have shown that through the appropriate design of meta-atom geometry, metasurfaces can be used to control light properties. However, most semitransparent metasurfaces are designed to perform symmetric operation with regard to diffraction, meaning that light diffraction occurs identically for front- and back-side illumination. We propose a simple single-layer plasmonic metasurface that achieves asymmetric diffraction by optimizing the transmission phase from two types of nanoslits with I- and T-shaped structures. As the proposed structure is designed to have a different effective period for each observation side, it is either diffractive or nondiffractive depending on the direction of observation. The designed structure exhibits a diffraction angle of 54°, which can be further tuned by applying different period conditions. We expect the proposed asymmetric diffraction meta-grating to have great potential for the miniaturized optical diffraction control systems in the infrared band and compact optical diffraction filters for integrated optics.


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