The speed with which integrated circuits work depends on the RC time constant
(time taken to
charge capacitors). It is essential to use material that has a low dielectric
constant so that RC
time constant is also low. Today, Hydrogen silsesquioxane (HSQ) with a dielectric
constant of
approximately 2.95 has been developed to be layered on the silicon base of
ICs. HSQ is a porous
material and is thus susceptible to moisture attack.
A method to treat low k dielectric material layer coated on a silicon substrate
which is simple,
cost effective and convenient has been developed by Prof. R. O. Dusane
and his students of
Department of Metallurgical Engineering and Materials Science. The method
does not damage
the dielectric layer, renders the dielectric layer very effective against
adverse effects of oxygen
plasma treatment, and improves the hydrophobicity of the dielectric layer
reducing moisture adsorption. Thus the leakage
of current is lowered improving performance of the treated IC. The process
developed also helps to deposit low dielectric
material (layer) on silicon base substrate and retain low dielectric properties
of the deposited layer.
HWGAH treatment eliminates use of RF generators and impedance matching
circuits, simplifying IC manufacturing. The
method does not damage the dielectric
layer, prevents penetration of oxygen
during plasma treatment and other
adverse effects. It also improves the repelling of water by the dielectric
layer, reducing its adsorption and subsequently
caused leakage of current. Since the dielectric property of the layer is
retained the performance of the IC manufactured
by this technology will be of higher quality.
Indian patent application no. 5/MUM/2006 Patent grant no. 232216
Inventors: R O Dusane, A A Kumbhar, S K Singh
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