Trap studies in GaInP/GaAs and AlGaAs/GaAs HEMT's by means of low-frequency noise and transconductance dispersion characterizations

The presence of traps in GaInP/GaAs and AlGaAs/GaAs HEMT's was investigated by means of low frequency noise and frequency dispersion measurements. Low frequency noise measurements showed two deep traps (E/sub a1/=0.58 eV, E/sub a2/=0.27 eV) in AlGaAs/GaAs HEMT's. One of them (E/sub a2/) is responsible for the channel current collapse at low temperature. A deep trap (E/sub a1/'=0.52 eV) was observed in GaInP/GaAs HEMT's only at a much higher temperature (/spl sim/350 K). These devices showed a transconductance dispersion of /spl sim/16% at 300 K which reduced to only /spl sim/2% at 200 K. The dispersion characteristics of AlGaAs/GaAs HEMT's were very similar at 300 K (/spl sim/12%) but degraded at 200 K (/spl sim/20%). The low frequency noise and the transconductance dispersion are enhanced at certain temperatures corresponding to trap level crossing by the Fermi-level. The transition frequency of 1/f noise is estimated at 180 MHz for GaInP/GaAs HEMT's and resembles that of AlGaAs/GaAs devices. >

[1]  S. Wright,et al.  Noise spectroscopy of deep level (DX) centers in GaAs‐AlxGa1−xAs heterostructures , 1988 .

[2]  H. Casey.  CHAPTER 2 – OPTICAL FIELDS AND WAVE PROPAGATION , 1978 .

[3]  P. Ladbrooke,et al.  Low-field low-frequency dispersion of transconductance in GaAs MESFETs with implications for other rate-dependent anomalies , 1988 .

[4]  D. Pavlidis,et al.  Frequency-dependent characteristics and trap studies of lattice-matched (x=0.53) and strained (x>0.53) In/sub 0.52/Al/sub 0.48/As/In/sub x/ Ga/sub 1-x/As HEMTs , 1991 .

[5]  J. Copeland.  Semiconductor impurity analysis from low-frequency noise spectra , 1971 .

[6]  M. Tutt,et al.  Low-frequency noise characteristics of lattice-matched (x=0.53) and strained (x>0.53) In/sub 0.52/Al/sub 0.48/As/InxGa/sub 1-/xAs HEMT's , 1992 .

[7]  H. Dambkes,et al.  Deep-level analysis in (AlGa)As—GaAs 2-D electron gas devices by means of low-frequency noise measurements , 1984, IEEE Electron Device Letters.

[8]  H. Kawai,et al.  Band lineup for a GaInP/GaAs heterojunction measured by a high‐gain Npn heterojunction bipolar transistor grown by metalorganic chemical vapor deposition , 1989 .

[9]  S. Kugler,et al.  Generation-recombination noise in the saturation regime of MODFET structures , 1988 .

[10]  S. Blight,et al.  Surface influence on the conductance DLTS spectra of GaAs MESFET's , 1986, IEEE Transactions on Electron Devices.

[11]  H. Morkoc,et al.  Low-noise behavior of InGaAs quantum-well-structured modulation-doped FET's from 10-2to 108Hz , 1986, IEEE Transactions on Electron Devices.

[12]  H. Morkoc,et al.  Bias dependence and light sensitivity of (Al, Ga)As/GaAs MODFET's at 77 K , 1983, IEEE Transactions on Electron Devices.

[13]  Manijeh Razeghi,et al.  Ga/sub 0.51/In/sub 0.49/P/GaAs HEMT's exhibiting good electrical performance at cryogenic temperatures , 1990 .