A comparative study of the electrical characteristics of metal-semiconductor-metal (MSM) photodiodes based on GaN grown on silicon

• Published in: Applied surface science 2005-08, Vol.249 (1), p.91-96
• Main Authors: Lee, Y.C., Hassan, Z., Yam, F.K., Abdullah, M.J., Ibrahim, K., Barmawi, M., Sugianto, Budiman, M., Arifin, P.
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Crystalline structure; Electrical characterization; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Electronics; Exact sciences and technology; III–V nitrides; Metal-semiconductor-metal structures; Optoelectronic devices; Photodiodes; Photodiodes; phototransistors; photoresistors; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2004.11.063

We report on the characteristics of metal-semiconductor-metal (MSM) photodiodes based on GaN films grown on silicon substrates by electron cyclotron resonance (ECR) plasma-assisted metalorganic chemical vapor deposition (PA-MOCVD) at growth temperature of 200 and 600 °C. Structural analysis of the GaN samples used for the photodiodes fabrication were performed by using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX) to analyze the crystalline quality of the samples. The analysis has revealed that the GaN samples grown at 200 and 600 °C were in amorphous and microcrystalline phase, respectively. Electrical characterization of the MSM photodiodes were carried out by using current–voltage ( I– V) measurements. At 10 V, the photodiodes based on amorphous GaN has a dark current of 0.18 μA while the microcrystalline GaN based photodiode has a dark current of 18 μA.