III–V Nitrides—thermodynamics and crystal growth at high N2 pressure

Enhanced sheet carrier densities in polarization controlled AlInN/AlN/GaN/InGaN field-effect transistor on Si (111)

“…As predicted by simulation the sample with the graded InGaN layer shows a significant increase of the sheet carrier concentration from 2.1x10 13 cm −2 for the reference sample to 2.9x10 13 cm −2 for the quasi 3DEG sample. Taking into account the thickness of about 10 nm of the graded InGaN layer the corresponding maximum indium content should be around 30 % according to the simulation results.…”

“…We defined the channel width as the region below the Fermi level. The calculated sheet carrier concentration for the InGaN containing structure is N S = 2.8x10 13 cm −2 while the simulations predict N S = 1.7x10 13 cm −2 for the conventional 2DEG FET structure.…”

“…Both piezoelectric as well as spontaneous polarization fields contribute to a triangular potential well where electrons or holes may be captured to realize the highly conductive channel region within field effect transistors. Very high electron concentrations well above 1x10 13 cm −2 can be achieved in GaN/AlInN FETs because of the high polarization discontinuity at the GaN/AlInN heterointerface. [7][8][9][10][11] In power devices thermal management is crucial which requires high thermal conductivity of the substrate.…”

“…Unfortunately, GaN-based materials can only be grown epitaxially on silicon substrates with sufficient quality if thermally-induced stresses during cool-down after the epitaxy process are compensated by structural design. [11][12][13] Otherwise, a network of cracks is introduced into the layer structure after cool down rendering device fabrication practically impossible. 14 Conceptual designs for electronic devices as developed on sapphire substrates, for example, need in general be re-considered for growth on silicon substrates.…”

Solid-state metathesis reactions under pressure: A rapid route to crystalline gallium nitride

“…[9][10][11][12][13] Single crystals of GaN are generally grown under high temperature ͑1700-1800 K͒/ high pressure conditions ͑Ͼ2 GPa for ϳ20 h͒ since GaN decomposes at ϳ1150 K under ambient pressure. [14][15][16] Recent experiments indicate sodium fluxes can be useful for crystal growth. 17 Solid-state metathesis ͑SSM͒ reactions have developed over the past several years into an effective rapid method for producing materials such as nitrides that are difficult to make using conventional techniques.…”