All-GaAs/AlGaAs readout circuit for quantum-well infrared detector focal plane array

We report the fabrication and testing of an all-GaAs/AlGaAs hybrid readout circuit operating at 77 K designated for use with an GaAs/AlGaAs background-limited quantum-well infrared photodetector focal plane array (QWIP FPA). The circuit is based on a direct injection scheme, using specially designed cryogenic GaAs/AlGaAs MODFET's and a novel n/sup +/-GaAs/AlGaAs/n/sup +/-GaAs semiconductor capacitor, which is able to store more than 15 000 electrons//spl mu/m/sup 2/ in a voltage range of /spl plusmn/0.7 V. The semiconductor capacitor shows little voltage dependence, small frequency dispersion, and no hysteresis. We have eliminated the problem of low-temperature degradation of the MODFET I-V characteristics and achieved very low gate leakage current of about 100 fA in the subthreshold regime. The MODFET electrical properties including input-referred noise voltage and subthreshold transconductance were thoroughly tested. Input-referred noise voltage as low as 0.5 /spl mu/V//spl radic/Hz at 10 Hz was measured for a 2/spl times/30 /spl mu/m/sup 2/ gate MODFET. We discuss further possibilities for monolithic integration of the developed devices.

[1]  Lester J. Kozlowski,et al.  LWIR 128*128 GaAs/AlGaAs multiple quantum well hybrid focal plane array , 1991 .

[2]  R. Kiehl,et al.  On the low-temperature degradation of (AlGa)As/GaAs modulation-doped field-effect transistors , 1986, IEEE Transactions on Electron Devices.

[3]  John H. Goebel,et al.  Cryogenic measurements of Aerojet GaAs n-JFETs , 1992, Defense, Security, and Sensing.

[4]  G. B. Tait,et al.  DC and large-signal time-dependent electron transport in heterostructure devices: an investigation of the heterostructure barrier varactor , 1995 .

[5]  Thomas J. Cunningham.  Progress in GaAs JFETs for 4-kelvin IR readout applications , 1996, Defense, Security, and Sensing.

[6]  W. J. Parrish,et al.  Long wavelength infrared 128*128 Al/sub x/Ga/sub 1-x/As/GaAs quantum well infrared camera and imaging system , 1993 .

[7]  Hickmott.  Fractional quantization in ac conductance of Alx , 1986, Physical review letters.

[8]  Y. Carbonneau,et al.  Γ‐X intervalley transfer in single AlAs barriers under hydrostatic pressure , 1993 .

[9]  Lester J. Kozlowski,et al.  2 x 64 GaAs readout for IR FPA application , 1992, Defense, Security, and Sensing.

[10]  Steven M. Baier,et al.  Complementary heterostructure FET readout technology for infrared focal-plane arrays , 1992, Defense, Security, and Sensing.

[11]  T. Baba,et al.  Elimination of Persistent Photoconductivity and Improvement in Si Activation Coefficient by Al Spatial Separation from Ga and Si in Al–Ga–As:Si Solid System –a Novel Short Period AlAs/n-GaAs Superlattice– , 1983 .

[12]  L. Escotte,et al.  Noise in AlGaAs/InGaAs/GaAs pseudomorphic HEMTs from 10 Hz to 18 GHz , 1993 .