Growth of semipolar high-indium-content InGaN quantum wells using InGaN tilting layer on Si(001)

Abstract

Low-toxity high-In-content InGaN is an attractive option for short-distance communications through plastic optical fibers because its performance is only slightly affected by temperature. However, its fabrication on the c-plane is impaired by In droplets and V pits, which form at low-growth temperature. On the other hand, unlike the c-plane, InGaN relaxes with tilting. Therefore, in this study, we first grew a high-In-content InGaN single layer, and then we fabricated an InGaN tilting layer between InGaN-based multiple quantum wells (MQWs) and GaN stripes/(001)Si. The emission wavelength increased with the InGaN tilting layer’s growth time because the strain was relaxed by misfit dislocations at the heterointerface. This layer also extended the emission peak of InGaN/GaN MQWs and increased the photoluminescence intensity with respect to that of a single-layered InGaN. Therefore, the InGaN tilting layer is effective for growing high-In-content InGaN MQWs.

Growth behavior of hexagonal GaN on Si(100) and Si(111) substrates prepared by pulsed laser deposition

“…Silicon is considered a very attractive substrate for the epitaxial growth of GaN and related materials used in lightemitting diodes [1][2][3] and high-electron-mobility transistors [4][5][6][7] because of its high thermal conductivity, the large diameter of available wafers, and its low cost. [8][9][10][11][12] However, the large mismatches in the lattice constant (16%) and thermal expansion coefficient (113%) between GaN and Si substrates lead to high densities of cracks and defects, which limit the device optoelectronic performance.…”