Highly-integrated thin film capacitor with high dielectric constant layer

Claim 1

A capacitor comprising: a silicon substrate; a polycrystalline silicon layer formed on said silicon substrate; a lower electrode layer including a silicon diffusion preventing conductive layer formed on said polycrystalline silicon layer and an oxidation resistance conductive layer formed on said silicon diffusion preventing conductive layer; a high dielectric constant layer formed on a top surface and a side surface of said oxidation resistance conductive layer; an upper electrode layer formed on said high dielectric constant layer, said silicon diffusion preventing conductive layer being isolated from said high dielectric constant layer; said capacitor further comprising a sidewall insulating spacer covering a sidewall of said silicon diffusion preventing conductive layer and having a height equal to said silicon diffusion preventing conductive layer and being located under said oxidation resistance conductive layer; said sidewall insulating spacer preventing said high dielectric constant layer from being in contact with said silicon diffusion preventing layer, thereby preventing oxidation of said silicon diffusion preventing layer during a growth of said high dielectric constant layer.