The Influence of Mechanical Stress on Hot-Carrier Degradation in Mosfet's

1993 ◽  
Vol 309 ◽  
Author(s):  
Ingrid De Wolf ◽  
Rudi Bellens ◽  
Guido Groeseneken ◽  
Herman E. Maes

AbstractNon-uniform hot-carrier degradation in n-channel polycide-gate MOSFET's with different thicknesses of the poly-Si film, and in p-channel polycide-gate MOSFET's with TiSi2- or CoSi2-gate-silicide, is studied. The n-MOSFET's with the thinnest poly-Si film, show an increased interface trap generation, while the influence of the gate-silicide material on the degradation behaviour of the p-MOSFET's is found to be very small. The results are evaluated in terms of the effect of mechanical stress on the degradation characteristics: favourable for compressive mechanical stress and unfavourable for tensile stress. A correlation with stress measurements by micro-Raman spectroscopy is made.

1993 ◽  
Vol 308 ◽  
Author(s):  
Ingrid De Wolf ◽  
Rudi bellens ◽  
Guido Groeseneken ◽  
Herman E. Maes

ABSTRACTNon-uniform hot-carrier degradation in n-channel polycide-gate MOSFET's with different thicknesses of the poly-Si film, and in p-channel polycide-gate MOSFET's with TiSi2- or CoSi2-gate-silicide, is studied. The n-MOSFET's with the thinnest poly-Si film, show an increased interface trap generation, while the influence of the gate-silicide material on the degradation behaviour of the p-MOSFET's is found to be very small. The results are evaluated in terms of the effect of mechanical stress on the degradation characteristics: favourable for compressive mechanical stress and unfavourable for tensile stress. A correlation with stress measurements by micro-Raman spectroscopy is made.


1998 ◽  
Author(s):  
I. De Wolf ◽  
G. Groeseneken ◽  
H.E. Maes ◽  
M. Bolt ◽  
K. Barla ◽  
...  

Abstract It is shown, using micro-Raman spectroscopy, that Shallow Trench Isolation introduces high stresses in the active area of silicon devices when wet oxidation steps are used. These stresses result in defect formation in the active area, leading to high diode leakage currents. The stress levels are highest near the outer edges of line structures and at square structures. They also increase with decreasing active area dimensions.


1993 ◽  
Vol 308 ◽  
Author(s):  
Ingrid De Wolf ◽  
Herman E. Maes ◽  
Hans Norström

ABSTRACTLocal mechanical stress introduced in the silicon substrate during the successive steps of poly-buffered local isolation of MOS integrated circuits is studied with micro-Raman spectroscopy. It is shown that the magnitude and the local variation of the stress is highly affected by the different processing steps. After deposition of the nitride mask, the stress can be described as caused by an edge-force. Field oxidation reduces the mask-induced stress but introduces thermal stress from the field oxide. Also the formation of the bird's beak gives rise to additional local tensile stress, especially at the tip of the bird's beak. Removal of the nitride mask results in a partial relaxation: the stress caused by the bird's beak relaxes. In this last stage of the isolation process, the stress image is mostly determined by the field oxide.


1995 ◽  
Vol 402 ◽  
Author(s):  
D. J. Howard ◽  
I. De Wolf ◽  
H. Bender ◽  
K. Maex

AbstractThe application of CoSi2 in ever shrinking Si CMOS source-drain technologies demands a better knowledge of the states of stress caused by the formation of cobalt-silicides in Si. In this study the variation in local mechanical stress in the silicon substrate near arrays of polycrystalline cobalt-silicide lines was investigated by micro-Raman spectroscopy. The lines were formed by annealing Co sputtered in windows in lithographically patterned, thermal oxide coated Si wafers. The CoSi2 lines varied in width from ˜0.25 to 5.0μ, in number from 2 to 7, and in thickness from ˜ 10 to 230nm. The spacing between lines was 1 and 3 times the line width.Trends in the Si stress between CoSi2 lines are described as a function of line width and line thickness. From the stress measured in the Si, information is obtained about the stress in the CoSi2 lines. In addition, the Si stress due to lines of primarily CoSi phase (monosilicide) is compared with the Si stress due to polycrystalline-CoSi2 (disilicide) lines.Cross section TEM and SEM micrographs of the CoSix line morphologies are used to aid the description of the resulting stress profiles. Some theoretical modeling of the stress in the Si due to the CoSix lines is presented for comparison with the micro-Raman spectroscopy results.


1996 ◽  
Vol 36 (11-12) ◽  
pp. 1751-1754 ◽  
Author(s):  
I. De Wolf ◽  
G. Pozzat ◽  
K. Pinardi ◽  
D.J. Howard ◽  
M. Ignat ◽  
...  

1998 ◽  
Vol 513 ◽  
Author(s):  
Zhi Chen ◽  
Jinju Lee ◽  
Joseph W. Lyding

ABSTRACTAn alternative approach for modeling the hot carrier degradation of the Si/SiO2 interface based on the dispersive characteristics of the interface trap generation has been proposed. The timedependent interface trap generation has been modeled using the stretched exponential expression. The conventional power law of degradation is just the approximation of this general form. Very good agreement has been found between the theoretical model and the experimental data. This approach gives more physical insight into the understanding of the mechanism for the interface trap generation.


2004 ◽  
Vol 21 (2) ◽  
pp. 403-405 ◽  
Author(s):  
Lei Zhen-Kun ◽  
Kang Yi-Lan ◽  
Hu Ming ◽  
Qiu Yu ◽  
Xu Han ◽  
...  

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