5/27/2023 0 Comments Electron installRecently, we evaluated the impact of various carbon-doping concentrations into the buffer with different undoped GaN channel thickness on the device performance. This requires extensive buffer engineering. In order to further push the performance limits of mm-wave ultrashort GaN transistors, the electron confinement and trapping effects under a high electric field must be optimized. A number of new device designs have been developed in this frame, including graded channel HEMTs and N-polar HEMT showing attractive performances in Ka-band and above. Breakthrough technologies are needed to achieve simultaneously high efficiency under high output power, together with high reliability. ![]() Therefore, further reducing the gate length to reach a higher frequency of operation requires significant changes of standard epitaxial materials and device design, such as self-aligned gates and an AlGaN back barrier. This is because they can deliver significantly higher 2DEG sheet carrier density compared to AlGaN/GaN HEMTs while offering the possibility to highly scale the epitaxial structure as needed when using short gate lengths. More recently, Al-rich ultrathin sub-10 nm barrier heterostructures have received much attention for millimeter-wave applications. ![]() Currently, the most matured GaN HEMTs are based on a AlGaN/GaN heterostructure. However, at a higher frequency, the efficiency and robustness of GaN HEMTs, especially under high drain bias above 15 V, are still limited due to enhanced trapping effects, reduced electron confinement and self-heating when downscaling the device size. ![]() ![]() Recent progress has allowed the demonstration of high RF performance up to Ka-band. In recent decades, remarkable progress has been achieved with GaN high electron mobility transistors (HEMTs) for use in high frequency power amplification and switching applications.
0 Comments
Leave a Reply. |