Author Affiliations
Abstract
1 State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
2 Beijing SinoGaN Semiconductor Technology Co., Ltd., Beijing 101399, China
3 Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
4 Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
The development of semiconductors is always accompanied by the progress in controllable doping techniques. Taking AlGaN-based ultraviolet (UV) emitters as an example, despite a peak wall-plug efficiency of 15.3% at the wavelength of 275 nm, there is still a huge gap in comparison with GaN-based visible light-emitting diodes (LEDs), mainly attributed to the inefficient doping of AlGaN with increase of the Al composition. First, p-doping of Al-rich AlGaN is a long-standing challenge and the low hole concentration seriously restricts the carrier injection efficiency. Although p-GaN cladding layers are widely adopted as a compromise, the high injection barrier of holes as well as the inevitable loss of light extraction cannot be neglected. While in terms of n-doping the main issue is the degradation of the electrical property when the Al composition exceeds 80%, resulting in a low electrical efficiency in sub-250 nm UV-LEDs. This review summarizes the recent advances and outlines the major challenges in the efficient doping of Al-rich AlGaN, meanwhile the corresponding approaches pursued to overcome the doping issues are discussed in detail.
AlGaN-based UV-LEDs Al-rich AlGaN doping Journal of Semiconductors
2024, 45(2): 021501
GaN基脊型激光二极管(LD)的制备工艺中, 面临的一个主要困难是p电极和窄脊结构的制备受到光刻对准精度的严重制约。设计和验证了一种基于背向曝光技术的激光器制备工艺。通过预先沉积一层200nm的铝作为挡光掩模和牺牲层, 利用ICP蚀刻制备出宽为2.5μm的脊型结构, 并使用PECVD沉积SiO2绝缘层。随后采用背向曝光实现二次光刻, 将脊型图形精确地转移到电极窗口, 继而采用湿法腐蚀SiO2绝缘层打开窗口, 借助对的铝掩模腐蚀实现对残余绝缘层的辅助剥离, 从而同时解决了目前脊型激光器电极窗口对准困难和绝缘层侧向腐蚀条件难于把握的问题。
激光器 脊型 背向曝光 掩埋金属层 laser diode ridge backward exposure buried metal mask
Author Affiliations
Abstract
1 Electrical Engineering Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
2 School of Physics and State Key Laboratory for Artif icial Microstructures and Mesoscopic Physics, Peking University, Beijing 100871
3 Electrical Engineering Department, California State University at Long Beach, Long Beach, CA 90840, USA
We present a grating model of two-dimensional (2D) rigorous coupled wave analysis (RCWA) to study top diffraction gratings on light-emitting diodes (LEDs). We compare the integrated-transmission of the non-grating, rectangular-grating, and triangular-grating cases for the same grating period of 6 \mum, and show that the triangular grating has the best performance. For the triangular grating with 6-\mm period, the LED achieves the highest light transmission at 6-m grating bottom width and 2.9-\mum grating depth. Compared with the non-grating case, the optimized light transmission improvement is about 74.6%. The simulation agrees with the experimental data of the thin polymer grating encapsulated flip-chip (FC) GaN-based LEDs for the light extraction improvement.
氮化镓 激光二极管 衍射光栅 140.0140 Lasers and laser optics 140.5960 Semiconductor lasers 050.1950 Diffraction gratings Chinese Optics Letters
2008, 6(10): 788
