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