Intentional control of n-type conduction for Si-doped AlN and AlXGa1−XN (0.42⩽x<1)

Abstract

We have obtained n-type conductive Si-doped AlN and AlXGa1−XN with high Al content (0.42⩽x<1) in metalorganic vapor phase epitaxy by intentionally controlling the Si dopant density, [Si]. Si-doped AlN showed the n-type conduction when [Si] was less than 3×1019 cm−3. When [Si] was more than 3×1019 cm−3, it became highly resistive due to the self-compensation of Si donors. This indicates that the self-compensation plays an important role at higher [Si] and determines the upper doping limit of Si for the AlN and AlXGa1−XN. For x⩾0.49, the ionization energy of Si donors increased sharply with increasing Al content. These resulted in a sharp decrease in the highest obtainable electron concentration with increasing Al content for the Si-doped AlXGa1−XN.

Si doping of high-Al-mole fraction AlxGa1−xN alloys with rf plasma-induced molecular-beam-epitaxy

“…Recently, there was a report on conducting Si-doped AlN. 16 The ionization energy data in that report also show a sudden increase in the Si donor ionization energy near 80% Al mole fraction, even though the ionization energy is much smaller, 83 meV in AlN, than 320 meV in the Ref. 12.…”

Inhomogeneous distribution of defect-related emission in Si-doped AlGaN epitaxial layers with different Al content and Si concentration

“…2) at room temperature. It is well known that Si doping into an Al x Ga 1-x N epitaxial layer drastically changes its structural, electrical, and optical properties through phenomena, such as dislocation inclination, 3 nano-mask effect, 4,5 changes in electric conductivity, 6,7 cathodoluminescence (CL) intensity enhancement, 8 introduction of point defects, 9 and changes in optical polarization along with variation in strain state. 10,11 For the fabrication of high-efficiency devices, it is important to investigate in detail the effects of Si doping on AlGaN ternary alloys.…”

Cathodoluminescence study of micro-crack-induced stress relief for AlN films on Si(111)

“…[1][2][3][4] Challenges in crystal growth due to the high-temperature growth requirement, 5,6 dopant incorporation problems, 7 and availability of suitable substrates for latticematching have limited the number of studies of AlN films. 8,9 In this study, we have performed a detailed spatially and spectrally resolved cathodoluminescence (CL) study for high-quality thin AlN films grown on Si(111), which could serve as a practical and convenient substrate for future synthesis and processing of AlGaN-based devices.…”