Thermodynamics of Ion-Cutting of β-Ga<sub>2</sub>O<sub>3</sub> and Wafer-Scale Heterogeneous Integration of a β-Ga<sub>2</sub>O<sub>3</sub> Thin Film onto a Highly Thermal Conductive SiC Substrate
Wenhui Xu, Tiangui You, Fengwen Mu, Zhenghao Shen, Jiajie Lin, Kai Huang, Min Zhou, Ailun Yi, Zhenyu Qu, Tadatomo Suga, Genquan Han, Xin Ou
Abstract
Heterogeneous integration of a β-Ga2O3 thin film with a highly thermal conductive substrate by the ion-cutting process is an intelligent technology to overcome the poor-nature thermal conductivity of β-Ga2O3 and to unleash the full potential of β-Ga2O3 in the field of power electronics. Understanding the basic mechanism of the implantation-induced exfoliation behavior of β-Ga2O3 is vital for better application of the ion-cutting technology. In this work, the thermodynamics of β-Ga2O3 surface blistering induced by H implantation was investigated via an in situ temperature-controlled microscopy stage. A large implantation fluence of H was needed for the ion-cutting of β-Ga2O3 because of the large activation energy (2.28 eV) and low utilization ratio of the implanted H ions (∼9%). A continuous micro-crack, which was essential for the exfoliation of the β-Ga2O3 thin film, was observed via a cross-sectional transmission electron microscope. A 2 in. β-Ga2O3 thin film was successfully transferred onto a 4-in. 4H-SiC substrate via the ion-cutting technique. The transferred β-Ga2O3 thin film exhibited great crystalline quality after a CMP and post-annealing process at 900 °C.