Epitaxial growth of a deposited amorphous Si layer formed on hydrogen-terminated Si(001) surfaces by ion beam induced epitaxial crystallization combined with ion beam mixing

Abstract

We have investigated the crystallization process of an amorphous Si layer deposited on hydrogen-terminated Si(001) surfaces by ion beam induced epitaxial crystallization (IBIEC) combined with the ion beam mixing (IBMX) method, aiming at the clarification of the essential IBMX effect on crystallization. In this study, we deposited a 10−15 nm thick amorphous Si layer on clean and two kinds of H-terminated Si(001) surfaces of dihydride (DH) and monohydride (MH), and then carried out the IBMX by 10-keV Si + ion irradiation with a fluence of 1 × 10 15 ions cm −2 at RT near the amorphous/crystalline interface followed by the IBIEC treatment by 180-keV Ar + ion irradiation with fluences of 5 × 10 15 and 1 × 10 16 ions cm −2 at 300 °C-500 °C. The thickness of the crystallized layer was quantitatively measured by the Rutherford backscattering channeling method. We found that the epitaxial crystallization of the amorphous Si layer formed on both DH and MH surfaces can be realized by IBMX followed by IBIEC treatments at significantly lower temperatures than 500 °C in all processes. This fact suggests that the epitaxial crystallization of the amorphous layer formed on the crystalline substrate surface terminated by the obstructive layer is effectively enhanced, regardless of the structure and coverage of the interfacial layers. It should be emphasized that the IBIEC combined with IBMX treatments make it possible to epitaxially crystallize the amorphous layers formed on obstructive layers covering crystalline substrates at significantly low temperatures.