Minority carrier diffusion length in GaN: Dislocation density and doping concentration dependence

We investigated the minority carrier diffusion length in p- and n-GaN by performing electron-beam-induced current measurements of GaN p–n junction diodes. Minority electron diffusion length in p-GaN strongly depended on the Mg doping concentration for relatively low dislocation density below 108cm−2. It increased from 220to950nm with decreasing Mg doping concentration from 3×1019to4×1018cm−3. For relatively high dislocation density above 109cm−2, it was less than 300nm and independent of the Mg doping concentration. On the other hand, the minority hole diffusion length in n-GaN was shorter than 250nm and less affected by the dislocation density and Si doping concentration. We discuss the doping-concentration and dislocation-density dependence of minority carrier diffusion length.

[1]  T. C. Mcgill,et al.  The values of minority carrier diffusion lengths and lifetimes in GaN and their implications for bipolar devices , 2000 .

[2]  T. C. McGill,et al.  Correlation between the surface defect distribution and minority carrier transport properties in GaN , 1998 .

[3]  Ulrike Grossner,et al.  The effect of doping and growth stoichiometry on the core structure of a threading edge dislocation in GaN , 1998 .

[4]  T. C. McGill,et al.  Electron diffusion length and lifetime in p-type GaN , 1998 .

[5]  S. Denbaars,et al.  Heavy doping effects in Mg-doped GaN , 2000 .

[6]  T. C. McGill,et al.  Minority carrier diffusion length and lifetime in GaN , 1998 .

[7]  K. Kumakura,et al.  High current gains obtained by InGaN/GaN double heterojunction bipolar transistors with p-InGaN base , 2001 .

[8]  Henryk Temkin,et al.  Electron beam induced current measurements of minority carrier diffusion length in gallium nitride , 1996 .

[9]  Masao Ikeda,et al.  Minority carrier diffusion length in GaN and ZnSe , 1998 .

[10]  H. Leamy,et al.  Charge collection scanning electron microscopy , 1982 .

[11]  Lester F. Eastman,et al.  The role of dislocation scattering in n-type GaN films , 1998 .

[12]  A. Osinsky,et al.  Enhancement of minority carrier transport in forward biased GaN p-n junction , 2001 .

[13]  K. Kumakura,et al.  High current gain (>2000) of GaN/InGaN double heterojunction bipolar transistors using base regrowth of p-InGaN , 2003 .

[14]  H. Hasegawa,et al.  Cathodoluminescence in-depth spectroscopy study of AlGaN/GaN heterostructures , 2003 .

[15]  P. Blood,et al.  The Electrical Characterization of Semiconductors: Measurement of Minority Carrier Properties , 1990 .

[16]  Jacek B. Jasinski,et al.  Electron beam and optical depth profiling of quasibulk GaN , 2000 .

[17]  James S. Speck,et al.  Correlated scanning Kelvin probe and conductive atomic force microscopy studies of dislocations in gallium nitride , 2003 .

[18]  K. Kumakura,et al.  Common-emitter current-voltage characteristics of a Pnp AlGaN/GaN heterojunction bipolar transistor with a low-resistance base layer , 2002 .