Wafer-Scale Si–GaN Monolithic Integrated E-Mode Cascode FET Realized by Transfer Printing and Self-Aligned Etching Technology

Abstract

In this article, Si (100) inks’ array is integrated on SiN/AlGaN/GaN substrate to demonstrate a zero deviation and wafer-scale Si–GaN monolithic integration by transfer printing and self-aligned etching technology. During the heterogeneous integration process, it does not depend on any equipment, such as metal–organic chemical vapor deposition (MOCVD) (epitaxial growth) and wafer bonding machine (wafer bonding) which are costly. The transferred Si and SiN/AlGaN/GaN substrates show an excellent interface morphology. Based on this material system, the monolithic integrated E-mode cascode FETs are demonstrated with good uniformity. The ${I}_{GS}$ is below 10−5 mA/mm within a large gate voltage swing of ±18 V. Threshold voltages of a series of cascode FETs are extracted as 2.2 V (±0.2 V). This novel low-cost technology shows great potential in monolithic heterogeneous integration.