Quality improvement of ZnO thin layers overgrown on Si(100) substrates at room temperature by nitridation pretreatment

To improve the quality of ZnO thin film overgrown on Si(100) substrate at RT (room temperature), the Si(100) surface was pretreated with different methods. The influence of interface on the overgrown ZnO layers was investigated by atomic force microscopy, photoluminescence and X-ray diffraction. We found that the nitridation pretreatment could significantly improve the quality of RT ZnO thin film through two-fold effects: one was to buffer the big lattice mismatch and ease the stress resulted from heterojunction growth; the other was to balance the interface charge, block the symmetric inheritance from the cubic Si (100) substrate and thus restrain the formation of zincblende phase.