Integration of III-V’s with Si has been under investigation for many years, but the physical material mismatch issues between the two have impaired all previous attempts at defect-free hetero-integration. The lattice constant mismatch and thermal expansion coefficient differences along with the heterovalent (i.e. polar/nonpolar) nature of the IIIV/Si interface are the sources of numerous harmful defects and material issues. Any credible solution to the hetero-integration of III-V/Si must include the control of these material concerns. GaP/Si is the most promising pathway toward accomplishing this goal, using the nearly lattice matched GaP to decouple the lattice mismatch obstacle from the other material issues.
This thesis focuses on the development of a process for the heteroepitaxial growth of GaP on Si(001) via MBE, demonstrating the suppression of nucleation-related defects, including antiphase domains (APD), stacking faults (SF) and microtwins (MT) arising from the polar/nonpolar interface. To accomplish this task, an extensive silicon substrate preparation study was conducted to create a suitable silicon surface for GaP nucleation at the initial stages of heteroepitaxy. Through these experiments, a clean DASR silicon surface was produced, creating an optimal surface template for GaP heteroepitaxial growth. GaP was then grown through migration enhanced epitaxy (MEE) to initiate planar GaP wetting layer at the polar/nonpolar interface, with GaP MBE subsequently grown on the GaP-MEE layer. The resultant GaP/Si heterointegrated materials system was characterized using AFM, TEM, XRD and SIMS finding for the first time, GaP/Si heteroepitaxially integrated using a process that effectively and simultaneously eliminated APDs, SFs and MTs. In addition, bulk GaP crystallinity was found to be exceptional and autodoping at the GaP/Si interface is sufficiently suppressed.