High linearity step-graded AlGaN/GaN heterojunction field effect transistor

We designed and fabricated the AlGaN/GaN HFETs with step graded heterostructure in this work. Compared with the AlGaN/GaN HFETs with linearly graded layer, the AlGaN/GaN HFETs with step graded layer exhibited similar device performance, including the notable wide flat transconductance characteristics. For the AlGaN/GaN step graded heterostructure, each step layer is individual and can be controlled separately during the epi-growth. Especially for the uniformity optimization, the individual growth mode for the AlGaN/GaN step graded heterostructure guarantee the targeted optimization for each layer. It is hoped that this step-graded structure would promote the industrialization of GaN devices in wireless communications applications.