论文信息 - Improved mobilities and resistivities in modulation-doped p-type AlGaN/GaN superlattices

Improved mobilities and resistivities in modulation-doped p-type AlGaN/GaN superlattices

The transport properties of modulation, shifted modulation, and uniformly doped Al0.20Ga0.80N/GaN superlattices are presented. The modulation-doped sample is doped only in the AlGaN barriers. The shifted-modulation-doped sample has its dopants shifted by one-quarter period. Measurements reveal a strong improvement in mobility and resistivity for the modulation-doped and shifted-modulation-doped structures versus the uniformly doped structure. The modulation-doped sample has a mobility of 9.2 and 36 cm2/V s at 300 and 90 K respectively and a very low resistivity of 0.20 and 0.068 Ω cm at 300 and 90 K, respectively. Capacitance–voltage profiling shows multiple two-dimensional hole gases. The results are consistent with a reduction of neutral impurity scattering for modulation-doped structures as compared to uniformly doped structures.

J. W. Graff | Erik L. Waldron | E. Fred Schubert

[1] D. Bour,et al. Hydrogen passivation of Mg acceptors in GaN grown by metalorganic chemical vapor deposition , 1995 .

[2] R. Street,et al. Activation of acceptors in Mg-doped GaN grown by metalorganic chemical vapor deposition , 1996 .

[3] A. Osinsky,et al. Demonstration of efficient p-type doping in Al/sub x/Ga/sub 1-x/N/GaN superlattice structures , 1999 .

[4] Adam W. Saxler,et al. Polarization-enhanced Mg doping of AlGaN/GaN superlattices , 1999 .

[5] Manijeh Razeghi,et al. Aluminum gallium nitride short-period superlattices doped with magnesium , 1999 .

[6] Vincenzo Fiorentini,et al. MACROSCOPIC POLARIZATION AND BAND OFFSETS AT NITRIDE HETEROJUNCTIONS , 1998 .

[7] Umesh K. Mishra,et al. ENHANCED MG DOPING EFFICIENCY IN AL0.2GA0.8N/GAN SUPERLATTICES , 1999 .

[8] W. Grieshaber,et al. Enhancement of deep acceptor activation in semiconductors by superlattice doping , 1996 .

[9] T. Metzger,et al. Properties and applications of MBE grown AlGaN , 1997 .

[10] Nicolas Grandjean,et al. Built-in electric-field effects in wurtzite AlGaN/GaN quantum wells , 1999 .

[11] H. Morkoç,et al. GaN, AlN, and InN: A review , 1992 .

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

[13] Pierre Lefebvre,et al. Quantum confined Stark effect due to built-in internal polarization fields in (Al,Ga)N/GaN quantum wells. , 1998 .