Imec reveals significant headway on 200mm GaN-on-Si tech

During the recent IEEE International Electron Devices Meeting 2015, Imec has showcased three novel aluminum gallium nitride (AlGaN)/gallium nitride (GaN) stacks featuring optimised low dispersion buffer designs. Moreover, the nano-electronics research centre optimised the epitaxial p-GaN growth process on 200mm silicon wafers, achieving e-mode devices featuring beyond modern high threshold voltage (Vt) and high drive current (Id).

To achieve a good, current-collapse-free device operation in AlGaN/GaN-on-Silicon (Si) devices, dispersion must be kept to a minimum. Trapped charges in the buffer between the GaN-based channel and the silicon substrate are known to be a critical factor in causing dispersion. Imec compared the impact of different types of buffers on dispersion and optimised three types: a classic step-graded buffer, a buffer with low-temperature AlN interlayers and a super lattice buffer. These three types of buffers were optimised for low dispersion, leakage and breakdown voltage over a wide temperature range and bias conditions.

During the recent IEEE International Electron Devices Meeting 2015, Imec presented three novel AlGaN/gallium nitride (GaN) stacks featuring optimised low dispersion buffer designs.

Imec also optimised the epitaxial p-GaN growth process demonstrating improved electrical performance of p-GaN HEMTs, achieving a beyond state-of-the-art combination of high threshold voltage, low on-resistance and high drive current (Vt >2V, RON = 7鈩?.mm and Id >0.4A/mm at 10V). The P-GaN HEMT results outperformed their MISHEMT counterparts.

Imec's GaN-on-Si R&D programme aims at bringing this technology towards industrialisation. Imec's offering includes a complete 200mm CMOS-compatible 200V GaN process line that features excellent specs on e-mode devices. Imec's programme allows partners early access to next-generation devices and power electronics processes, equipment and technologies, and speed up innovation at shared costs. Current R&D focuses on improving the performance and reliability of Imec's e-mode devices, while in parallel pushing the boundaries of the technology through innovation in substrate technology, higher levels of integration and exploration of novel device architectures.