Study And Fabrication Of Si-based Photo-&Electro-luminescence Device Prepared By PECVD

Si-based light emission devices are the key to realize optoelectric integration in VLSI and MEMS. However, it is very difficult for Silicon as an indirect-gap semiconductor to emit light efficiently. The realization of IC processes compatible, low cost and practical Si-based light emission device impacts the development of optoelectric IC, optical memory and logic, and advanced display system.The paper proposes a novel structure of Si-based vertical cavity surface photo-&electro-luminescence(PL&EL) device and theoretical analysis as well as experimental fabrication is made on them. The devices are fabricated by PECVD, whose Bragg mirrors consist of a-Si:H/a-SiOx:H multifilms and the Fabry-Perot cavity is filled with a-SiCx:H or a-SiCx:H p-i junction as the luminescence layer. The devices function light emission under laser or DC voltage excitation. Abundant experiments have been done to investigate the fabrication techniques and optical-electrical properties of a-Si:H, a-SiOx, a-SixNy, a-SiCx:H and Boron doped p type a-SiCx:H. The devices are fabricated based on the simulations, which is made on reflective spectra to decide the device parameters including film quantity, refractive index, thickness and growth sequence. The red, green and blue light PL devices with DBR/a-SiCx:H/DBR structure and red, blue light EL devices with DBR/ITO/p type a-SiCx:H/a-SiCx:H/Al structure are fabricated respectively. Especially, under DC voltage of 18V, the blue light EL device can emit light at 483nm with the FWHM of 20nm, whose intensity is 10 times enhanced than that of p-i junction EL spectrum. This result is comparable to the international level of Si-based light emission research. The realization of red, green, blue light PL devices and red, blue light EL devices establishes a good foundation for fabricating room-temperature PL and EL visible light emission device and color flat display.