图形蓝宝石衬底GaN基发光二极管的研制

采用抗刻蚀性光刻胶作为掩膜,并利用光刻技术制作周期性结构,进行ICP干法刻蚀C面(0001)蓝宝石制作图形蓝宝石衬底(PSS);然后,在PSS上进行MOCVD制作GaN基发光二极管(LED)外延片;最终,进行芯片制造和测试。PSS的基本结构为圆孔,直径为3μm,间隔为2μm,深度为864 nm,呈六角形分布。与同批生长的普通蓝宝石衬底(CSS)GaN基LED芯片相比,PSS芯片的光强和光通量比CSS分别提高57.32%和28.33%(20 mA),并可减小芯片的反向漏电流,且未影响芯片的波长分布和电压特性。

Development of GaN-based light emitting diode on patterned sapphire substrate

Using anti-etching photoresist as a mask,and with lithography producing periodic structure,c-plane(0001) patterned sapphire substrate(PSS) was fabricated by inductively coupled plasma(ICP) dry etching.Then GaN-based LED epitaxial wafers were grown on PSS by metal organic chemical vapor deposition(MOCVD).Ultimately,LED chips were manufactured and tested.The PSS contains a periodically spaced round hole structure,where the holes have a width of 3 μm,a depth of 864 nm,and they are separated from each other in an interval of 2 μm,and distributed as hexagons.Compared with conventional sapphire substrate(CSS) LED of the same batch MOCVD,PSS LED′s EL-intensity and luminous flux increased by 57.32% and 28.33% at 20 mA,respectively,and it had reduced reverse leakage current,but PSS had no significant impact on the wavelength distribution and voltage characteristics of the LED chips.