Thermal mismatch strain induced disorder of Y2Mo3O12 and its effect on thermal expansion of Y2Mo3O12/Al composites

2017 ◽  
Vol 19 (19) ◽  
pp. 11778-11785 ◽  
Author(s):  
Chang Zhou ◽  
Qiang Zhang ◽  
Saiyue Liu ◽  
Bingcheng Luo ◽  
Eongyu Yi ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Squeeze Casting ◽  
Thermal Mismatch ◽  
Mismatch Strain

Fully dense Y2Mo3O12/Al composites were prepared by squeeze casting.

New physically based model for thermal induced initial stress in 3D for silicon germanium films after deposition

2014 ◽  
Vol 33 (6) ◽  
pp. 2121-2138 ◽  
Author(s):  
Abderrazzak El Boukili
Keyword(s):  
Thermal Expansion ◽  
Initial Stress ◽  
Silicon Germanium ◽  
Rate Of Change ◽  
Thermal Mismatch ◽  
Electronic Band ◽  
Physically Based Model ◽  
Content Type ◽  
Physically Based ◽  
Pmos Transistor

Purpose – The purpose of this paper is to provide a new three dimension physically based model to calculate the initial stress in silicon germanium (SiGe) film due to thermal mismatch after deposition. We should note that there are many other sources of initial stress in SiGe films or in the substrate. Here, the author is focussing only on how to model the initial stress arising from thermal mismatch in SiGe film. The author uses this initial stress to calculate numerically the resulting extrinsic stress distribution in a nanoscale PMOS transistor. This extrinsic stress is used by industrials and manufacturers as Intel or IBM to boost the performances of the nanoscale PMOS and NMOS transistors. It is now admitted that compressive stress enhances the mobility of holes and tensile stress enhances the mobility of electrons in the channel. Design/methodology/approach – During thermal processing, thin film materials like polysilicon, silicon nitride, silicon dioxide, or SiGe expand or contract at different rates compared to the silicon substrate according to their thermal expansion coefficients. The author defines the thermal expansion coefficient as the rate of change of strain with respect to temperature. Findings – Several numerical experiments have been used for different temperatures ranging from 30 to 1,000°C. These experiments did show that the temperature affects strongly the extrinsic stress in the channel of a 45 nm PMOS transistor. On the other hand, the author has compared the extrinsic stress due to lattice mismatch with the extrinsic stress due to thermal mismatch. The author found that these two types of stress have the same order (see the numerical results on Figures 4 and 12). And, these are great findings for semiconductor industry. Practical implications – Front-end process induced extrinsic stress is used by manufacturers of nanoscale transistors as the new scaling vector for the 90 nm node technology and below. The extrinsic stress has the advantage of improving the performances of PMOSFETs and NMOSFETs transistors by enhancing mobility. This mobility enhancement fundamentally results from alteration of electronic band structure of silicon due to extrinsic stress. Then, the results are of great importance to manufacturers and industrials. The evidence is that these results show that the extrinsic stress in the channel depends also on the thermal mismatch between materials and not only on the material mismatch. Originality/value – The model the author is proposing to calculate the initial stress due to thermal mismatch is novel and original. The author validated the values of the initial stress with those obtained by experiments in Al-Bayati et al. (2005). Using the uniaxial stress generation technique of Intel (see Figure 2). Al-Bayati et al. (2005) found experimentally that for 17 percent germanium concentration, a compressive initial stress of 1.4 GPa is generated inside the SiGe layer.

The interfacial reliability of through-glass vias for 2.5D integrated circuits

2020 ◽  
Vol 37 (4) ◽  
pp. 181-188
Author(s):  
Omar Ahmed ◽  
Golareh Jalilvand ◽  
Scott Pollard ◽  
Chukwudi Okoro ◽  
Tengfei Jiang
Keyword(s):  
Integrated Circuits ◽  
Material Selection ◽  
Thermal Mismatch ◽  
Element Analysis ◽  
Content Type ◽  
Interfacial Delamination ◽  
Mismatch Strain ◽  
Aspect Ratios ◽  
Interfacial Reliability ◽  
The Impact

Purpose Glass is a promising interposer substrate for 2.5 D integration; yet detailed analysis of the interfacial reliability of through-glass vias (TGVs) has been lacking. The purpose of this paper is to investigate the design and material factors responsible for the interfacial delamination in TGVs and identify methods to improve reliability. Design/methodology/approach The interfacial reliability of TGVs is studied both analytically and numerically. An analytical solution is presented to show the dependence of the energy release rate (ERR) for interfacial delamination on the via design and the thermal mismatch strain. Then, finite element analysis (FEA) is used to investigate the influence of detailed design and material factors, including the pitch distance, via aspect ratio, via geometry and the glass and via materials, on the susceptibility to interfacial delamination. Findings ERR for interfacial delamination is directly proportional to the via diameter and the thermal mismatch strain. Thinner wafers with smaller aspect ratios show larger ERRs. Changing the via geometry from a fully filled via to an annular via leads to lower ERR. FEA results also show that certain material combinations have lower thermal mismatch strains, thus less prone to delamination. Practical implications The results and approach presented in this paper can guide the design and development of more reliable 2.5 D glass interposers. Originality/value This paper represents the first attempt to comprehensively evaluate the impact of design and material selection on the interfacial reliability of TGVs.

Thermal-mismatch-strain relaxation in epitaxialCaF2,BaF2/CaF2, and PbSe/BaF2/CaF2layers on Si(111) after many temperature cycles

1994 ◽  
Vol 50 (15) ◽  
pp. 10801-10810 ◽  
Author(s):  
H. Zogg ◽  
S. Blunier ◽  
A. Fach ◽  
C. Maissen ◽  
P. Müller ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Thermal Mismatch ◽  
Temperature Cycles ◽  
Mismatch Strain

Thermal Mismatch Strain Relaxation Mechanisms and Hysteresis in Pb1−SnxSe-on-CaF2/Si Structures

1995 ◽  
Vol 379 ◽  
Author(s):  
H. Zogg ◽  
P. Müller ◽  
A. Fach ◽  
J. John ◽  
C. Paglino ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Structural Quality ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Thermal Mismatch ◽  
Mismatch Strain ◽  
Threading Dislocation Density ◽  
Deformation Hardening ◽  
Interaction Probability

ABSTRACTThe strain induced by the thermal mismatch in Pbl−xSnxSe and other IV–VI compound layers on Si(111)-substrates relaxes by glide of dislocations in the main <110> {001}-glide system. The glide planes are arranged with 3-fold symmetry and inclined to the (111)-surface. Despite a high threading dislocation density (> 107 cm−2) in these heavily lattice mismatched structures, the misfit dislocations move easily even at cryogenic temperatures and after many temperature cycles between RT and 77K. The cumulative plastic deformation after these cycles is up to 500%! Despite a pronounced deformation hardening occurs, the structural quality of the layer is only slightly adversely affected as regards additional threading dislocations created. The interaction probability between these dislocations is estimated to be about 10−5.

Thermal mismatch induced disorder of beta-eucryptite and its effect on thermal expansion of beta-eucryptite/Al composites

2012 ◽  
Vol 72 (13) ◽  
pp. 1613-1617 ◽  
Author(s):  
L.D. Wang ◽  
Z.W. Xue ◽  
Y. Cui ◽  
K.P. Wang ◽  
Y.J. Qiao ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Thermal Mismatch
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