The Dependence of Poly-Si TFT Characteristics on the Relative Misorientation Between Grain Boundaries and the Active Channel

2000 ◽  
Vol 621 ◽  
Author(s):  
Y.H. Jung ◽  
J.M. Yoon ◽  
M.S. Yang ◽  
W.K. Park ◽  
H.S. Soh ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Device Performance ◽  
Boundary Misorientation ◽  
Leakage Currents ◽  
Hot Carrier ◽  
Glass Substrates ◽  
Notable Effect ◽  
Threshold Voltages ◽  
Grain Boundary Misorientation ◽  
Active Channel

ABSTRACTWe present device-related experimental results that quantitatively reveal the effect of varying the active channel/grain-boundary misorientation on the resulting TFT characteristics. Specifically, using low-temperature SLS processes, we have fabricated and analyzed n-channel and p-channel devices (40 μm width × 8 μm length) with three different orientations of the channel with respect to the grain boundaries: parallel, 45° inclined, and perpendicular on Corning 1737 glass substrates.The results reveal that the TFTs with the best (worst) characteristics were obtained for the devices with parallel (perpendicular) alignment. In general, for both n- and p-channel devices, the most prominent orientation-dependent effects were observed in the values of the field effect mobilities, which were 340, 227, and 141 cm2/Vsec for n-channel devices and 145, 105, and 80 cm2/Vsec for p-channel devices, in the order of increasing orientation mismatch. In contrast, no notable effect was manifested in the leakage currents, while small effects were seen for the sub-threshold slopes and threshold voltages. The degradation of device performance under hot-carrier stress was found to decrease with increasing orientation mismatch.

Measurement of solute segregation to grain boundaries in the AEM: A review

1988 ◽  
Vol 46 ◽  
pp. 606-607
Author(s):  
D. B. Williams ◽  
A. D. Romig
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Boundary Misorientation ◽  
Collector Plate ◽  
Segregation Process ◽  
Grain Boundary Misorientation ◽  
Structure Boundary ◽  
Equilibrium Segregation

The segregation of solute or imparity elements to grain boundaries can occur by three well-defined processes. The first is Gibbsian segregation in which an element of minimal matrix solubility confines itself to a monolayer at the grain boundary. Classical examples include Bi in Cu and S or P in Fe. The second process involves the depletion of excess matrix solute by volume diffusion to the boundary. In the boundary, the solute atoms diffuse rapidly to precipitates, causing them to grow by the ‘collector-plate mechanism.’ Such grain boundary diffusion is thought to initiate “Diffusion-Induced Grain Boundary Migration,” (DIGM). This process has been proposed as the origin of eutectoid transformations or discontinuous grain boundary reactions. The third segregation process is non-equilibrium segregation which result in a solute build-up around the boundary because of solute-vacancy interactions.All of these segregation phenomena usually occur on a sub-micron scale and are often affected by the nature of the grain boundary (misorientation, defect structure, boundary plane).

Characterization of Zinalco Alloy Superplastically Deformed Using Orientation Imaging Microscopy

2009 ◽  
Vol 1242 ◽  
Author(s):  
Ramos A. Mitsuo ◽  
Martínez F. Elizabeth ◽  
Negrete S. Jesús ◽  
Torres-Villaseñor G.
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Superplastic Deformation ◽  
Orientation Imaging Microscopy ◽  
Grain Boundary Sliding ◽  
Boundary Misorientation ◽  
Average Grain Size ◽  
Grain Boundary Misorientation ◽  
Misorientation Angles

ABSTRACTZinalco alloy (Zn-21mass%Al-2mass%Cu) specimens were deformed superplastically with a strain rate (ε) of 1×10-3 s-1 at homologous temperature (TH) of 0.68 (5 ). It was observed neck formation that indicate nonhomegeneus deformation. Grain size and grain boundaries misorientation changes, due superplastic deformation, were characterized by Orientation Imagining Microscopy (OIM) technique. It was studied three regions in deformed specimens and the results were compared with the results for a specimen without deformation. Average grain size of 1 mm was observed in non-deformed specimen and a fraction of 82% for grain boundary misorientation angles with a grain boundaries angles between 15° and 55° was found. For deformed specimen, the fraction of angles between 15° and 55° was decreced to average value of 75% and fractions of low angle (<5°) and high angle (>55°) misorientations were 10% and 15% respectively. The grain size and high fraction of grain boundary misorientation angles between 15° and 55° observed in the alloy without deformation, are favorable for grain rotation and grain boundary sliding (GBS) procces. The changes observed in the fraction of favorable grain boundary angles during superplastic deformation, shown that the superplastic capacity of Zinalco was reduced with the deformation.

Variant Selection in Fcc-to-Bcc Precipitation at Grain Boundaries in Ni-43Cr Alloy

2005 ◽  
Vol 475-479 ◽  
pp. 305-308 ◽  
Author(s):  
Yoshitaka Adachi ◽  
Fu Xing Yin ◽  
Kazunari Hakata ◽  
Kaneaki Tsuzaki
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Tilt Angle ◽  
Boundary Plane ◽  
Variant Selection ◽  
Orientation Relationships ◽  
Boundary Misorientation ◽  
Grain Boundary Plane ◽  
Grain Boundary Misorientation ◽  
Selection Of

Variant selection of bcc-Cr at the grain boundaries in a supersaturated fcc matrix was studied using a Ni-43Cr alloy. The preferentially selected variant was examined as a function of the grain boundary misorientation, the tilt angle between the {111}fcc plane and the grain boundary plane, and the orientation relationships with respect to both of the adjacent matrix grains.

scholarly journals Influence of multiaxial cyclic plastic loading on grain boundary misorientation profile in austenitic stainless steel

2019 ◽  
Vol 300 ◽  
pp. 08007
Author(s):  
Rima Dey ◽  
Soumitra Tarafder ◽  
S Sivaprasad
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Multiaxial Loading ◽  
Loading Conditions ◽  
Load Path ◽  
Boundary Misorientation ◽  
Proportional Loading ◽  
Dominant Mechanism ◽  
Load Paths ◽  
Grain Boundary Misorientation

304LN stainless was subjected to multiaxial loading employing different waveforms and load paths. The grain boundary misorientation profile so obtained post deformation was compared across loading conditions. It was found that the uniaxial and proportional conditions of loading result in more of twins, contrary to non-proportional loading conditions that resulted in substantially higher low angle grain boundaries. Also, under non-proportional loading the trapezoidal load path resulted in remarkably altered distribution of the grain boundaries compared to its contemporaries. Predominant martensitic transformation was found to be dominant mechanism of deformation for trapezoidal loading that also contributed to the altered misorientation profile.

Influence of Grain Boundary Structure on Liquid Metal Penetration Behavior

1999 ◽  
Vol 578 ◽  
Author(s):  
Liping Ren ◽  
D.F. Bahr ◽  
R.G. Hoagland
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Simulation Method ◽  
High Energy ◽  
Boundary Structure ◽  
Boundary Misorientation ◽  
Kikuchi Pattern ◽  
Grain Boundary Structure ◽  
Grain Boundary Misorientation ◽  
Penetration Behavior

AbstractThe penetration of Ga along Al grain boundaries under stress-free conditions is investigated in the present study. In-situ SEM observations indicate that the penetration rate of Ga along Al grain boundaries at room temperature ranged from 6.4 to 9.2 μm/s, which is similar to the rate of diffusion in the liquid state. For a specific high energy grain boundary, the grain boundary misorientation is determined from the TEM diffraction Kikuchi pattern, and a molecular statics simulation method was employed to investigate grain boundary structure. A comparison of the structure of this high energy boundary is made with the Σ11(131)[101] tilt grain boundary that is not penetrated by Ga in the absence of the applied stress. The results indicate that the grain boundary plane void structure in the high energy grain boundary may provide void channels for Ga monolayer penetration. In addition, penetration behavior investigated under different length scales supports this model.

Anisotropic Grain Boundary Segregation in Y-Doped TiO2

2001 ◽  
Vol 7 (S2) ◽  
pp. 280-281
Author(s):  
G. D. Lian ◽  
A. Susalla ◽  
E. C. Dickey
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Level Structure ◽  
Boundary Segregation ◽  
Solute Segregation ◽  
Grain Boundary Segregation ◽  
Boundary Misorientation ◽  
Mole Percent ◽  
Dielectric System ◽  
Grain Boundary Misorientation

A variety of properties of polycrystalline TiO2, such as conductivity, creep and grain boundary diffusion, are strongly dependent on the atomic-level structure and chemistry of grain boundaries. TiO2 has been studied as a model dielectric system because of its relatively simple structure and well-understood point defect chemistry. Defect segregation in grain boundaries of polycrystalline and bi-crystal TiO2 have been studied by several groups and significant variations in solute segregation levels from boundary to boundary were observed. in this paper, we address this issue of anisotropic grain boundary segregation. We have measured solute segregation as a function of grain boundary misorientation to determine any correlation between segregation and misorientation.Yttria-doped TiO2 polycrystalline samples were prepared by mixing 99.999% pure TiO2 powder with 0.1% mole percent 99.99% purity Y(NO3)3 (both powders are commercially available from Aldrich Co. or Alfa Co.), followed by uni-axial pressed to 200-400Pa and sintering at 1300 °C for about 5-7 hours.

A Novel High-Stress Pre-Metal Dielectric Film to Improve Device Performance for sub-65nm CMOS Manufacturing

2006 ◽  
Vol 913 ◽  
Author(s):  
Young Way Teh ◽  
John Sudijono ◽  
Alok Jain ◽  
Shankar Venkataraman ◽  
Sunder Thirupapuliyur ◽  
...  
Keyword(s):  
Performance Improvement ◽  
Dielectric Film ◽  
High Stress ◽  
Significant Degree ◽  
Strain Effect ◽  
Device Performance ◽  
Hot Carrier ◽  
Tcad Simulation ◽  
Improve Device ◽  
Deposition Techniques

AbstractThis work focuses on the development and physical characteristics of a novel dielectric film for a pre-metal dielectric (PMD) application which induces a significant degree of tensile stress in the channel of a sub-65nm node CMOS structure. The film can be deposited at low temperatures to meet the requirements of NiSi integration while maintaining void-free gap fill and superior film quality such as moisture content and uniformity. A manufacturable and highly reliable oxide film has been demonstrated through both TCAD simulation and real device data, showing ~6% NMOS Ion-Ioff improvement; no Ion-Ioff improvement or degradation on PMOS. A new concept has been proposed to explain the PMD strain effect on device performance improvement. Improvement in Hot Carrier immunity is observed compared to similar existing technologies using high density plasma (HDP) deposition techniques.

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