Electrical Exploding Nickel and Tungsten Wires in Air and Water

2009 ◽  
Author(s):  
George B. Vunni
Keyword(s):  
And Tungsten

Influence of carbon fibers and tungsten disulfide on the properties and structure of polytetrafluoroethylene

2018 ◽  
Vol 4 (3) ◽  
pp. 26-34
Author(s):  
A. A. Okhlopkova ◽  
A. P., Vasilev ◽  
T. S. Struchkova ◽  
A. G. Alekseev ◽  
P. N. Grakovich
Keyword(s):  
Carbon Fibers ◽  
Tungsten Disulfide ◽  
And Tungsten

A Latent Issue of Via Resistance: Mechanism and Solution

2018 ◽  
Author(s):  
Wentao Qin ◽  
Scott Donaldson ◽  
Dan Rogers ◽  
Lahcen Boukhanfra ◽  
Julien Thiefain ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Chemical Mechanical Planarization ◽  
Resistance Mechanism ◽  
Formation Enthalpy ◽  
Metal Line ◽  
Device Failure ◽  
Valence Electrons ◽  
Wafer Processing ◽  
Field Failure ◽  
And Tungsten

Abstract Many semiconductor products are manufactured with mature technologies involving the uses of aluminum (Al) lines and tungsten (W) vias. High resistances of the vias were sometimes observed only after electrical or thermal stress. A layer of Ti oxide was found on such a via. In the wafer processing, the post W chemical mechanical planarization (WCMP) cleaning left residual W oxide on the W plugs. Ti from the overlaying metal line spontaneously reduced the W oxide, through which Ti oxide formed. Compared with W oxide, the Ti oxide has a larger formation enthalpy, and the valence electrons of Ti are more tightly bound to the O ion cores. As a result, the Ti oxide is more resistive than the W oxide. Consequently, the die functioned well in the first test in the fab, but the via resistance increased significantly after a thermal stress, which led to device failure in the second test. The NH4OH concentration was therefore increased to more effectively remove residual W oxide, which solved the problem. The thermal stress had prevented the latent issue from becoming a more costly field failure.

Hydrogenolytic cleavage of pyridine on different cobalt-molybdenum and nickel-tungsten catalysts

1981 ◽  
Vol 46 (6) ◽  
pp. 1348-1354 ◽  
Author(s):  
Mirko Černý ◽  
Miloš Kraus
Keyword(s):  
Reaction Products ◽  
Hydrogenation Activity ◽  
Catalyst Composition ◽  
Tungsten Catalysts ◽  
Nickel Tungsten ◽  
And Tungsten

Composition of the reaction products formed by hydrogenation of pyridine at 300 °C and 15 MPa in the presence of 15 sulphided and unsulphided molybdenum and tungsten catalysts promoted by cobalt and by nickel, respectively, using alumina as the support in most cases, has been examined. It has been proved that the catalyst composition affects both its hydrogenation activity and the ratio of transalkylation to cracking (or hydrocracking) reactions. Relations between the catalyst composition and its activity and selectivity found for the reaction of pyridine differ from those reported for hydrogenolytic cleavage of thiophene, hydrogenation and isomerization of cyclohexene.

Sign in / Sign up

Export Citation Format

Share Document