Modeling UpLink power control with outage probabilities
Kenneth L. Clarkson, K. Georg Hampel, et al.
VTC Spring 2007
The use of CVD tungsten for filling of contacts and vias has been reported in many multilevel interconnection technology applications. W-stud formation is done by blanket tungsten deposition and subsequent either etchback or Chemical-Mechanical polishing(CMP).1 This paper presents the integration of both tungsten deposition and etchback processes in a commercial cluster tool, as compared to W-stud formation by CMP. Tungsten films were deposited at a high pressure of 70 Torr to fill high aspect ratio(3.5) contact holes without voids. Tensile stress of 10E9 dynes/cm2 measured for these films was higher by almost a factor of 2 than the low pressure tungsten films deposited at 0.85 Torr. A composite W film, deposited by both high and low pressure regime, has been utilized to have both advantages of via-filled characteristic and low film stress. A multistep RIE process had been used with the majority of W removed using a SF6/C12 plasma and the remaining W was then removed with Cl2/O2 to minimize the microloading phenomenon.2 3 The maximum W-plug recess, observed at the edge of the wafers, is only 0.1μm. Electrical test results of W contact studs formed by clustered processes is compared to W-stud formation by CMP.
Kenneth L. Clarkson, K. Georg Hampel, et al.
VTC Spring 2007
Ehud Altman, Kenneth R. Brown, et al.
PRX Quantum
R.B. Morris, Y. Tsuji, et al.
International Journal for Numerical Methods in Engineering
Imran Nasim, Michael E. Henderson
Mathematics