Epitaxial growth of Ti1-xAlxN buffer layer for a ferroelectric (Ba, Sr)TiO3 capacitor on Si substrate

Epitaxial titanium aluminum nitride, Ti1-xAlxN(100) (0 less than or equal to x < 0.5), was grown on Si(100) substrates at 600 degrees C by low-energy reactive ion beam deposition using N-2(+) ion beam irradiation with 100eV energy and Ti and Al simultaneous evaporation. The epitaxial relationship was confirmed to be Ti1-xAlxN(100)parallel to Si(100), Ti1-xAlxN[110]parallel to Si(110) by X-ray diffraction XRD) and in situ reflection high-energy electron diffraction (RHEED). Although the electrical resistivity increased exponentially with x, the values remained on the order of 10(-4) Omega.cm. Using the Ti1-xAlxN buffer layer, we have successfully fabricated a capacitor with an epitaxial (Ba, Sr)TiO3 film on a Si substrate.