Infrared reflection absorption spectroscopy using CoSi₂ buried metal layer substrate made by wafer-bonding

The vibration spectroscopy with sufficient sensitivity for sub-monolayer adsorbates on the semiconductor surface is extremely important in developing nano-process. The conventional infrared reflection absorption spectroscopy (IRRAS) covers wide energy regions including so-called finger print region with sub-monolayer sensitivity. However, it is applicable only for the metal. Therefore we have developed the IRRAS using buried metal layer (BML) substrate. BML wafers have been made so far by ion implantation method. This methods, however, has several problems. A large ion current required for the ion implantation often cause the breakdown of the ion implanter. It is difficult to remove the surface roughness due to the ion implantation damage even after epitaxial growth. In this paper we have fabricated BML substrates with atom-level flat surfaces by a wafer-bonding technique and applied them for the measurement of self-assembled alkyl monolayers on the semiconductor surface.