Doping is essential for modulating semiconductor conductivity,forming p-n junctions,and reducing contact resistance[1].Notably,as organic semiconductors(OSCs)advance toward high performance,flexibility,and miniaturiza...Doping is essential for modulating semiconductor conductivity,forming p-n junctions,and reducing contact resistance[1].Notably,as organic semiconductors(OSCs)advance toward high performance,flexibility,and miniaturization,achieving precise regionally selective doping becomes critical for building complex,highly integrated devices[2].In inorganic semiconductors(e.g.,silicon),sub-100-nanometer regional doping is achievable through photolithography and ion implantation—techniques foundational to modern complementary metaloxide-semiconductor(CMOS)technology[3].展开更多
High-temperature-annealed Al N(HTA-Al N) templates provide ideal substrates for high-quality Al Ga N epitaxy. However, the significant compressive stress accumulated within the Al Ga N layer makes it challenging to ac...High-temperature-annealed Al N(HTA-Al N) templates provide ideal substrates for high-quality Al Ga N epitaxy. However, the significant compressive stress accumulated within the Al Ga N layer makes it challenging to achieve a smooth surface free of hexagonal hillocks on these templates. To address this issue, we investigate the mechanism of compressive stress accumulation during the growth of Al Ga N-based epilayers on HTA-Al N templates using in-situ curvature analysis in this study. To verify the mechanism, a low-Al-content Al Ga N interlayer is introduced between the Al N epilayer and the subsequent Al Ga N epilayer. The larger a-plane lattice constant of this interlayer relative to the Al Ga N epilayer slows the accumulation rate of compressive stress. The hexagonal hillock can be effectively suppressed and the surface of Al Ga N epilayer can be significantly regulated by adopting various low-Al-content Al Ga N interlayers. This work provides a comprehension on the stress accumulation mechanism in Al Ga N epilayers and a feasible method to obtain hillock-free surface of Al Ga N epilayers on HTA-Al N templates,which will be beneficial for fabricating Al Ga N based devices.展开更多
文摘探索了一种X射线反射(X-ray reflectance,XRR)表征六方氮化硼(Hexagonal boron nitride,h-BN)薄膜厚度的测试方法。通过金属有机化学气相沉积在蓝宝石衬底上生长不同厚度的h-BN薄膜,并利用拉曼光谱表征,证实了h-BN薄膜在蓝宝石衬底上的成功生长。对比了不同生长条件的h-BN与蓝宝石衬底的XRR测试曲线,表明XRR测试曲线振荡与薄膜厚度强相关。通过拟合XRR测试曲线来获得h-BN的厚度值与材料密度值,经对比发现拟合厚度值与原子力显微镜(Atomic force microscopy,AFM)测试或透射电子显微镜(Transmission electron mi‑croscopy,TEM)测试值一致,同时发现3.5 nm厚度的样品材料密度值与体材料密度值接近,但2 nm以下样品的材料密度均值低于体材料。
文摘Doping is essential for modulating semiconductor conductivity,forming p-n junctions,and reducing contact resistance[1].Notably,as organic semiconductors(OSCs)advance toward high performance,flexibility,and miniaturization,achieving precise regionally selective doping becomes critical for building complex,highly integrated devices[2].In inorganic semiconductors(e.g.,silicon),sub-100-nanometer regional doping is achievable through photolithography and ion implantation—techniques foundational to modern complementary metaloxide-semiconductor(CMOS)technology[3].
基金supported by the National Key R&D Program of China (Grant No. 2022YFB3605000)the National Natural Science Foundation of China (Nos. 62004127, 61725403, 62121005, 61922078, 61827813, and 62004196)+1 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciencesthe Youth Talent Promotion Project of the Chinese Institute of Electronics (No. 2020QNRC001)。
文摘High-temperature-annealed Al N(HTA-Al N) templates provide ideal substrates for high-quality Al Ga N epitaxy. However, the significant compressive stress accumulated within the Al Ga N layer makes it challenging to achieve a smooth surface free of hexagonal hillocks on these templates. To address this issue, we investigate the mechanism of compressive stress accumulation during the growth of Al Ga N-based epilayers on HTA-Al N templates using in-situ curvature analysis in this study. To verify the mechanism, a low-Al-content Al Ga N interlayer is introduced between the Al N epilayer and the subsequent Al Ga N epilayer. The larger a-plane lattice constant of this interlayer relative to the Al Ga N epilayer slows the accumulation rate of compressive stress. The hexagonal hillock can be effectively suppressed and the surface of Al Ga N epilayer can be significantly regulated by adopting various low-Al-content Al Ga N interlayers. This work provides a comprehension on the stress accumulation mechanism in Al Ga N epilayers and a feasible method to obtain hillock-free surface of Al Ga N epilayers on HTA-Al N templates,which will be beneficial for fabricating Al Ga N based devices.
