Heterojunction bipolar transistor using a (Ga,In)P emitter on a GaAs base, grown by molecular beam epitaxy

Abstract

We report the first N-p-n heterojunction bipolar transistor (HBT) using a (Ga,In)P/GaAs heterojunction emitter on a GaAs base. This combination is of interest as a potential alternate to (Al,Ga)As/GaAs, because of theoretical predictions of a larger valence band discontinuity and a smaller conduction band discontinuity, thus eliminating the need for grading of the emitter/base junction. The structure was grown by molecular beam epitaxy, with the base doping ( -lOI9cm -3 ) far exceeding the n-type doping ( -5 * "ern-') of the (Ga,In)P wide gap emitter (EE = 1.88 eV). Common-emitter current gains of 30 were attained at a current density of 3000 A/cm2, the highest current density achieved without burnout.

Tensile-strained InxGa1−xP membranes for cavity optomechanics

“…Epitaxial InGaP thin films are commonly employed in microwave transistors owing to the superior electronic properties (band alignment with GaAs, high electron saturation velocity, etc.) [15], as well as their unique chemical properties, namely the potential for selective etching with respect to GaAs and AlGaAs compounds [16]. The latter property has also led to the use of InGaP as a sacrificial material in the development of micromechanical resonators [17].…”

Improved InGaP/GaAs/InGaP δ-doped double-HBT with InGaP passivation layer and effects of layer-thickness on device performance

“…The InGaP/GaAs material system has been proposed to replace the AlGaAs/GaAs heterostructure due to its favourable properties which make it more attractive for Npn heterojunction bipolar transistors (HBTs) [1,2]. The advantages that using InGaP/GaAs material in HBT fabrication bring are (1) that a large valence band offset at the E-B heterointerface allows a nearly unity electron injection efficiency [1][2][3]; (2) extremely high selective etching between the N-InGaP emitter and p + -GaAs base, resulting in precise deposition of ohmic metal on the base layer [4]; and (3) the potential to form a very sharp pn junction during epitaxial growth [5].…”

“…The advantages that using InGaP/GaAs material in HBT fabrication bring are (1) that a large valence band offset at the E-B heterointerface allows a nearly unity electron injection efficiency [1][2][3]; (2) extremely high selective etching between the N-InGaP emitter and p + -GaAs base, resulting in precise deposition of ohmic metal on the base layer [4]; and (3) the potential to form a very sharp pn junction during epitaxial growth [5]. Problems related to DX centres and degradation of a wide-gap AlGaAs emitter might also be avoided.…”

Electrical isolation of InGaP by proton and helium ion irradiation

“…Structures consisting of an epitaxial In 0.49 Ga 0.51 P layer grown matched on GaAs are promising for the fabrication of microelectronic and optoelectronic devices, such as heterojunction bipolar transistors ͑HBTs͒ with wide-band-gap emitters 1 and laser structures composed by InGaP/GaAs confining layers and InGaAs quantum well active regions. 2 An important subject, which is related to fabrication of devices using such structures, is electrical isolation.…”