Photoionization spectroscopy of traps in GaN metal-semiconductor field-effect transistors

Measurements of the spectral and intensity dependences of the optically-induced reversal of current collapse in a GaN metal-semiconductor field-effect transistor (MESFET) have been compared to calculated results. The model assumes a net transfer of charge from the conducting channel to trapping states in the high-resistivity region of the device. The reversal, a light-induced increase in the trap-limited drain current, results from the photoionization of trapped carriers and their return to the channel under the influence of the built-in electric field associated with the trapped charge distribution. For a MESFET in which two distinct trapping centers have been spectrally resolved, the experimentally measured dependence upon light intensity was fitted using this model. The two traps were found to have very different photoionization cross-sections but comparable concentrations (4×1011 cm−2 and 6×1011 cm−2), suggesting that both traps contribute comparably to the observed current collapse.

[1]  M. Khan,et al.  Fundamental optical transitions in GaN , 1996 .

[2]  K. Doverspike,et al.  High-power microwave GaN/AlGaN HEMTs on semi-insulating silicon carbide substrates , 1999, IEEE Electron Device Letters.

[3]  Ellen B. Stechel,et al.  Charge accumulation at a threading edge dislocation in gallium nitride , 1999 .

[4]  H. Morkoç,et al.  Large‐band‐gap SiC, III‐V nitride, and II‐VI ZnSe‐based semiconductor device technologies , 1994 .

[5]  D. C. Reynolds,et al.  Deep‐center hopping conduction in GaN , 1996 .

[6]  T. Takagi,et al.  Film Growth of GaN on a c-Axis Oriented ZnO Film Using Reactive Ionized-Cluster Beam Technique and Its Application to Thin Film Devices , 1983 .

[7]  Walter Kruppa,et al.  Correlation of Drain Current Pulsed Response with Microwave Power Output in AlGaN/GaN HEMTs , 1999 .

[8]  Michael S. Shur,et al.  Current/voltage characteristic collapse in AlGaN/GaN heterostructure insulated gate field effect transistors at high drain bias , 1994 .

[9]  H. Grubin.  The physics of semiconductor devices , 1979, IEEE Journal of Quantum Electronics.

[10]  Theeradetch Detchprohm,et al.  Analysis of deep levels in n‐type GaN by transient capacitance methods , 1994 .

[11]  Y. Crosnier,et al.  Trap effects studies in GaN MESFETs by pulsed measurements , 1999 .

[12]  Jaime A. Freitas,et al.  Observation of deep traps responsible for current collapse in GaN metal-semiconductor field-effect transistors , 1999 .

[13]  E. Haller,et al.  Persistent photoconductivity in n-type GaN , 1997 .

[14]  A. S. Grove.  Physics and Technology of Semiconductor Devices , 1967 .

[15]  J C Inkson,et al.  Deep impurities in semiconductors. II. The optical cross section , 1981 .

[16]  James C. M. Hwang,et al.  Relationship between gate lag, power drift, and power slump of pseudomorphic high electron mobility transistors , 1999 .

[17]  Marc Ilegems,et al.  Infrared Lattice Vibrations and Free-Electron Dispersion in GaN , 1973 .

[18]  C. D. Wang,et al.  Persistent photoconductivity and defect levels in n-type AlGaN/GaN heterostructures , 1998 .

[19]  Michael S. Shur,et al.  Instabilities in modulation doped field-effect transistors (MODFETs) at 77 K , 1983 .

[20]  Jaime A. Freitas,et al.  Fabrication and Characterization of GaN FETs , 1997 .

[21]  L. Eastman,et al.  GaN Materials for High Power Microwave Amplifiers , 1998 .

[22]  H. Morkoç,et al.  Thermally stimulated current trap in GaN , 1996 .

[23]  H. Morkoc,et al.  On the collapse of drain I-V characteristics in modulation-doped FET's at cryogenic temperatures , 1984, IEEE Transactions on Electron Devices.

[24]  Mooney Pm,et al.  Evidence for large lattice relaxation at the DX center in Si-doped AlxGa , 1988 .

[25]  A. Y. Polyakov,et al.  Studies of the origin of the yellow luminescence band, the nature of nonradiative recombination and the origin of persistent photoconductivity in n-GaN films , 1998 .

[26]  H. Okumura,et al.  The origin of persistent photoconductivity and its relationship with yellow luminescence in molecular beam epitaxy grown undoped GaN , 1998 .

[27]  J. Moll,et al.  Field induced reemission of electrons trapped in SiO2 , 1979, IEEE Transactions on Electron Devices.

[28]  D. Grider,et al.  Drain current compression in GaN MODFETs under large-signal modulation at microwave frequencies , 1999 .