Effects of wet-oxidation treatment on Al[sub 0.45]Ga[sub 0.55]As/GaAs graded-like superlattice-emitter bipolar transistor with low turn-on voltage

Lour, Wen-Shiung; Wu, Yen-Wei; Tan, Shih-Wei; Tsai, Ming-Kwen; Yang, Ying-Jay
May 2002
Applied Physics Letters;5/6/2002, Vol. 80 Issue 18, p3436
Academic Journal
We report an Al[sub x]Ga[sub 1-x]As/GaAs heterojunction bipolar transistor (HBT) with a high Al mole fraction of x = 0.45. A digital graded superlattice emitter, forming a step-wise graded composition, is used to smooth out the potential spike resulting from a large conduction-band offset. HBT's with such a digital graded emitter as a passivation layer exhibit a small offset voltage of 55 mV, a low turn-on voltage of 0.87 V and a current gain as high as 400. Effects of wet-oxidation treatment on fabricated HBT's are also investigated. Experimental results reveal that the studied HBT's exhibit reduced collector currents at a fixed base current in the early stage of the wet-oxidation treatment. However, better surface passivation and higher current gain are available after an appropriate wet-oxidation treatment is used to reduce base current. We qualitatively modeled these behaviors by introducing a concept of built-in field along the graded emitter.


Related Articles

  • Effect of collector-base valence-band discontinuity on Kirk effect in double-heterojunction.... Mazhari, B.; Morkoc, H. // Applied Physics Letters;10/21/1991, Vol. 59 Issue 17, p2162 

    Examines the effect of collector-base valence band discontinuity on the current gain and base charge storage of bipolar transistors. Influence of barrier height on base transit time and current gain; Formation of the current-induced base; Pros and cons of double-heterojunction bipolar transistors.

  • Conduction-band discontinuity in InGaP/GaAs measured using both current-voltage and.... Lee, T.W.; Houston, P.A. // Applied Physics Letters;1/27/1992, Vol. 60 Issue 4, p474 

    Measures the conduction-band discontinuity in indium gallium phosphide/gallium arsenide heterojunction. Use of current-voltage and photoemission methods; Growth of double-heterojunction bipolar transistor structures by molecular beam epitaxy; Details on the conduction band offset value in the...

  • Multiple negative differential resistance of InP/InGaAs superlattice-emitter resonant-tunneling bipolar transistor at room temperature. Jung-Hui Tsai // Applied Physics Letters;9/29/2003, Vol. 83 Issue 13, p2695 

    Sequential resonant-tunneling behavior of a resonant-tunneling bipolar transistor with five-period i-InP/n-InGaAs superlattice emitter has been demonstrated. An interesting multiple negative differential resistance (NDR) phenomena resulting from the creation and extension of the high-field...

  • InP/GaAsSb/InP and InP/GaAsSb/InGaAsP double heterojunction bipolar transistors with a.... Bhat, R.; Hong, W.-P. // Applied Physics Letters;2/12/1996, Vol. 68 Issue 7, p985 

    Examines the effectivity of GaAsSb as base material to eliminate conduction band potential barrier in indium phosphide (InP) based double heterojunction bipolar transistors (DHBT). Indication for DHBT band alignment; Growth of InP/InGaAs DHBT by organometallic chemical vapor deposition;...

  • Observation of Bloch conduction perpendicular to interfaces in a superlattice bipolar transistor. Palmier, J. F.; Minot, C.; Lievin, J. L.; Alexandre, F.; Harmand, J. C.; Dangla, J.; Dubon-Chevallier, C.; Ankri, D. // Applied Physics Letters;11/10/1986, Vol. 49 Issue 19, p1260 

    We report the first operating bipolar transistor built with an AlGaAs/GaAs superlattice base. High current gain is measured with a suitable design of the bipolar transistor structure. Experimental results are in good agreement with a Bloch to hopping transition which is very sensitive to the...

  • Improvement of current gain of C-doped GaAsSb-base heterojunction bipolar transistors by using an InAlP emitter. Oda, Yasuhiro; Yokoyama, Haruki; Kurishima, Kenji; Kobayashi, Takashi; Watanabe, Noriyuki; Uchida, Masahiro // Applied Physics Letters;7/11/2005, Vol. 87 Issue 2, p023503 

    Large conduction band edge discontinuity (ΔEc) at the emitter/base interface in InP/GaAs0.51Sb0.49/InP heterojunction bipolar transistor (HBT) is one of the possible reasons that the recombination process in the emitter/base depletion region dominates the characteristics of this HBT. We...

  • Blocking of Lambda...X transfer in GaAs/AlAs short period superlattices due to X-state band filling. Blom, P.W.M.; Smit, C.; Haverkort, J.E.M.; Wolter, J.H. // Applied Physics Letters;5/10/1993, Vol. 62 Issue 19, p2393 

    Examines the prohibition of lambda to X transfer in GaAs and AlAs short period superlattices by X-state band filling. Optical properties of the superlattice; Induction of the transfer process by LO-phonon emission or interface scattering; Transformation of emission spectrum from type-I into a...

  • Theory of zone-folded optical transitions in semiconductor superlattices. Lazzouni, M.E.; Sham, L.J. // Applied Physics Letters;12/13/1993, Vol. 63 Issue 24, p3253 

    Examines the theory of zone-folded optical transitions in semiconductor superlattices. Use of the one-dimensional two-band tight binding model; Dependence of optical strength on growth direction and strain; Calculation for the oscillator strength; Similarities of the constituents for band...

  • Large optical nonlinearities in semiconductor superlattices. Morrison, I.; Jaros, M.; Beavis, A. W. // Applied Physics Letters;10/16/1989, Vol. 55 Issue 16, p1609 

    We show that the nonlinear response of a direct-gap semiconductor superlattice is greatly enhanced when the separation of the lowest two conduction minibands approaches the magnitude of the principal gap. Two structures exhibiting this enhanced nonlinear response are described.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics