GaN nano‐pendeo‐epitaxy on Si(111) substrates

Abstract

Nano‐pendeo‐epitaxial GaN films have been grown by metalorganic vapour phase epitaxy on nanocolumns fabricated on thin GaN‐on‐Si(111) templates. Optical and structural performances of the films are improved, crack densities are reduced, and self‐separation of GaN films from the substrates at the nanocolumns has been realized. The success of the nano‐pendeo‐epitaxy of GaN films is attributed to the following three techniques developed in this study: (1) the growth of high quality ultrathin GaN/AlN templates on on Si(111) substrates, (2) the fabrication of uniform nanocolumns across the 2‐inch wafer surface, and (3) the in situ conversion of the exposed silicon surfaces of the fabricated nanocolumns to silicon nitride. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Prospects of III-nitride optoelectronics grown on Si

“…NELO growth of GaN by MOVPE has been investigated on nanopatterned silicon on insulator (Zubia et al 2000), nanopatterned GaN/AlN/Si templates (Zang et al 2005, Liu et al 2009 and on dense arrays of Si(1 1 1) nanopillars (Hersee et al 2005); significant reductions in TD density were observed due to the TD bending. TEM studies showed that the NELO GaN grown on Si nanopillars has a TD density <10 8 cm −2 , but stacking faults near the GaN/Si interface and grain boundaries are also present (Hersee et al 2005).…”

“…In addition to TD reduction, Liu et al found that the GaN/AlN/Si nanocolumns can also inhibit cracking (Liu et al 2009). The possible strain reduction mechanisms are: (1) the strain in the nano-epitaxy GaN layer is relaxed through a 3D deformation of the nano-columns before coalescence as illustrated in figure 19; (2) the tensile strain introduced during the GaN film coalescence and cooling down is released through nano-column deformation, with some columns even breaking to release the strain energy during cooling.…”

Modelling wafer bow in silicon–polycrystalline CVD diamond substrates for GaN-based devices

“…While (100) orientated silicon can be used for diamond on silicon [19] this work initially considers (111) orientation silicon since it is for c-plane GaN epitaxial growth [20]. The elastic modulii of isotropic silicon and their temperature dependence are determined using the approach of Varshni [21], which is derived from the Einstein model for a solid and are given by…”