Temperature Effect on the Quality of A1N thin Films

Abstract

AlN thin films were deposited at various substrate temperatures via Plasma Source Molecular Beam Epitaxy. The films were grown on 6H-SiC (0001) substrates. Reflection High Energy Electron Diffraction and Atomic Force Microscopy showed a dramatic change in the surface morphology of the film grown at 640 o C. This is attributed to a change in the growth mechanism from pseudomorphic at lower temperatures to three-dimensional at higher than 640 o C temperatures. Photoreflectance measurements showed an absorption shift toward 200 nm as the deposition temperature increases which is attributed to the change in the growth mechanism at higher temperatures. X-Ray Diffraction was unable to conclusively determine the AlN (0002) peak due to a significant diffuse intensity from the SiC (0002) peak. A MIS structure was created by depositing Pt contacts on the film grown at 500 o C. I-V measurements showed that the Pt/AlN contact is Schottky.

Optical characterization of sputtered amorphous aluminum nitride thin films by spectroscopic ellipsometry

“…Aluminum nitride (AlN) has received increasing attention from the material research community due to its unique properties [1,2] which make AlN films promising materials not only for applications in optoelectronics and microelectronic devices [3,4], but also for surface passivation of semiconductors and insulators, and in surface acoustic wave device applications [5,6]. Another major interest in this insulator stems from its ability to form alloys with the group III nitrides such as AlGaN [7] and AlGaInN [8], allowing the fabrication of AlGaN/GaN based electronic and optical device applications.…”

Development of Wide Bandgap Semiconductor Photonic Device Structures by Excimer Laser Micromachining

“…Considering the space allowed in this paper, we refer the sample quality information of AlN to our former reports. 8,9,10 Two arrays were ablated on raw Silicon (111) substrates at single pulse energy of 0.5 mJ. In the first array, the number of laser pulses were increased from 10 to 20 in one pulse increments; in the second array, the number of laser pulses were increased from 10 to 100 in increments of 10.…”

Microstructure and Thermal Stability of Aluminum Nitride Thin Films Deposited at Low Temperature on Silicon

“…[1][2][3][4][5] Recent development of the III-nitrides has extended their application greatly in the area of electrical devices as well as optical devices. AlN has been proposed as a potential replacement for silicon dioxide ͑SiO 2 ͒ in high-temperature metal insulator semiconductor ͑MIS͒, [6][7][8][9][10][11] silicon carbide ͑SiC͒-based, [12][13][14][15][16][17][18] and GaN-based device applications. [19][20][21][22] AlN is a wide-bandgap semiconductor, but when undoped its properties are most like those of an insulator with a dielectric constant, , of 8.5.…”