Electron transport in AlGaN–GaN heterostructures grown on 6H–SiC substrates

We investigated two-dimensional electron transport in doped AlGaN–GaN heterostructures (with the electron sheet concentration ns≈1013 cm−2) grown on conducting 6H–SiC substrates in the temperature range T=0.3–300 K. The electron mobility in AlGaN–GaN heterostructures grown on SiC was higher than in those on sapphire substrates, especially at cryogenic temperatures. The highest measured Hall mobility at room temperature was μH=2019 cm2/V s. At low temperatures, the electron mobility increased approximately five times and saturated below 10 K at μH=10250 cm2/V s. The experimental results are compared with the electron mobility calculations accounting for various electron scattering mechanisms.We investigated two-dimensional electron transport in doped AlGaN–GaN heterostructures (with the electron sheet concentration ns≈1013 cm−2) grown on conducting 6H–SiC substrates in the temperature range T=0.3–300 K. The electron mobility in AlGaN–GaN heterostructures grown on SiC was higher than in those on sapphire substrates, especially at cryogenic temperatures. The highest measured Hall mobility at room temperature was μH=2019 cm2/V s. At low temperatures, the electron mobility increased approximately five times and saturated below 10 K at μH=10250 cm2/V s. The experimental results are compared with the electron mobility calculations accounting for various electron scattering mechanisms.

[1]  Michael S. Shur,et al.  Monte Carlo calculation of velocity-field characteristics of wurtzite GaN , 1997 .

[2]  J. Guo,et al.  Mobility enhancements in AlGaN/GaN/SiC with stair-step and graded heterostructures , 1997 .

[3]  K. Malloy,et al.  The Microstructure of Metalorganic-Chemical-Vapor-Deposition GaN on Sapphire , 1997 .

[4]  M. Shur,et al.  Microwave performance of 0.25μm doped channel GaN/AlGaN heterostructure field effect transistor at elevated temperatures , 1997 .

[5]  M. Shur,et al.  Piezoresistive effect in GaN–AlN–GaN structures , 1997 .

[6]  Carleton H. Seager,et al.  Grain Boundaries in Polycrystalline Silicon , 1985 .

[7]  James S. Speck,et al.  Role of threading dislocation structure on the x‐ray diffraction peak widths in epitaxial GaN films , 1996 .

[8]  The influence of the deformation on the two-dimensional electron gas density in GaN–AlGaN heterostructures , 1998 .

[9]  M. Shur,et al.  Cyclotron resonance and quantum Hall effect studies of the two-dimensional electron gas confined at the GaN/AlGaN interface , 1997 .

[10]  M. Shur,et al.  Hall factor for ionized impurity scattering , 1995 .

[11]  R. Gaska,et al.  High-temperature performance of AlGaN/GaN HFETs on SiC substrates , 1997, IEEE Electron Device Letters.

[12]  B. Pödör.  Electron Mobility in Plastically Deformed Germanium , 1966 .

[13]  M. Shur,et al.  Electron mobility in two-dimensional electron gas in AIGaN/GaN heterostructures and in bulk GaN , 1996 .

[14]  Michael A. Littlejohn,et al.  Monte Carlo calculation of the velocity‐field relationship for gallium nitride , 1975 .

[15]  M. Shur,et al.  Monte Carlo simulation of electron transport in gallium nitride , 1993 .