Sokartes T. Pantelides
IBM Research Division
Thomas J. Watson Research Center
Yorktown Heights, N.Y.
A recent paper gives an interesting view, strictly experimental, on the possibility of an electromagnetic "fifth " force, in complete analogy with the highly controversial gravitational fifth force.
D.F. Bartlett, S. L"gl, "Limits on an electromagnetic fifth force," Physical Review Letters, 61 (20), 2285, 14 November 1988.
The dispersion front of a tracer fluid flowing in a porous medium has a fractal structure. Fractal geometry abounds in nature, but the principles that determine fractal dimension still remain a challenge.
C.J. McKinstrie, D.A. Russell, "Nonlinear focusing of coupled waves," Physical Review Letters, 61 (26), 2929-32, 26 December 1988.
Buried interfaces are hard to probe experimentally. Scanning tunneling microscopy is a winner again and provides the basis for a new technique that monitors the behavior of ballistic electrons as they traverse the interface.
L.D. Bell, W.J. Kaiser, "Observation of interface band structure by ballistic-electron-emission microscopy," Physical Review Letters, 61 (20), 2368-71, 14 November 1988.
As the dimensions of devices shrink in very large-scale integration, new processing techniques need to be invented. A new electron cyclotron resonance plasma method can successfully be used to dope the sidewalls of very high-aspect ratio trenches such as those needed for 16 Mbit dynamic random access memories.
B. Mizuno, I. Nakayama, N. Aoi, M. Kubota, T. Komeda, "New doping method for subhalf micron trench sidewalls by using an electron cyclotron resonance plasma," Applied Physics Letter, 53 (21), 2059-2061, 21 November 1988.