Investigations on InP/InAlAsSb/GaAs Metamorphic High Electron Mobility Transistors with a Dual-Composition-Graded InxGa1−xAs1−ySby Channel and Different Schottky-Barrier Gate Structures

Abstract

Device characteristics of InP/In 0.34 Al 0.66 As 0.85 Sb 0.15 /GaAs metamorphic high electron mobility transistors with a dual-compositiongraded In x Ga 1Àx As 1Ày Sb y (x ¼ 0.53 ! 0.63 ! 0.53, y ¼ 0.01 ! 0.02 ! 0.01) channel are comprehensively investigated by forming different Schottky-barrier gate structures of Pt/Au-In 0.34 Al 0.66 As 0.85 Sb 0.15 , Ni/Au-In 0.34 Al 0.66 As 0.85 Sb 0.15 , or Pt/Au-InP, respectively. Superior device gain, current drive, power, noise, and high-frequency characteristics have been achieved due to relieved kink effects and decreased gate leakages, which are caused by the decreased electron concentration in the channel and suppressed thermionic emission by forming high Schottky-barrier gate structures. High-temperature device characteristics at 300-450 K are also studied. Excellent thermal threshold stability is achieved due to the combinational effects of both barrier-lowering and carrier-carrier scattering mechanisms at high temperatures.

Threading Dislocations in S-Graded ZnSxSe1-x/GaAs (001) Metamorphic Buffer Layers

“…Metamorphic devices which have been fabricated on lattice-mismatched substrates include InGaAs/InAlAs HEMTs on GaAs, 3 InGaAs/InAlAs heterojunction bipolar transistors (HBTs) on GaAs, 4 InGaAs/InP HEMTs and HBTs on GaAs, 5 InAlAs photodiodes on GaAs, 6 InAsSb/AlInAsSb light-emitting diodes (LEDs) on GaSb, 7 AlInGaAsSb laser diodes on GaSb, 8 InGaAs/InAlGaAs laser diodes on GaAs, 9 InGaAsSb/InAlAs quantum cascade laser structures on GaAs, 10 and InAlAs solar cells on GaAs. 11 Most work has focused on linearly-graded buffer layers, [2][3][4][5][6][7][8][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] while there have been several reports of the use of step-graded buffer layers 12,[31][32][33][34] or buffer layers with T. Kujofsa continuous, but non-linear grading of composition. 11,[35][36][37] Tersoff's work …”

Comparative studies of MOS-gate/oxide-passivated AlGaAs/InGaAs pHEMTs by using ozone water oxidation technique

“…For the conventional Schottky-gated HEMTs, the gate leakages are mainly resulted from the current injection through (1) the thermionic emission-enhanced barrier lowering at the Schottky barrier and (2) thermionic trap-assisted tunneling mechanism through the surface states upon the exposed barrier layer between the gate-drain/source regions [9]. In order to enhance the Schottky barrier height, depositing gate metals of high work function on wide-gap barrier layer has been attempted [10]. Other approaches using SiN [11][12] or sulfide [13][14] surface passivation techniques have also been studied.…”

Study of Metamorphic Co-Integrated Heterostructure Bipolar and Field-Effect Transistors (BiFETs)

“…Recently, some of InP-based metamorphic transistors grown on low-cost GaAs substrates have been investigated. [7][8][9][10] Previous report had demonstrated that the InGaP buffer could offer better thermal properties resulting in a much smaller thermal resistance in the metamorphic HBTs when compared to the widely used InAlAs metamorphic buffer. 7 In this paper, a new InP/InGaAs co-integrated metamorphic heterostructure bipolar and field-effect transistor (BiFETs) is first demonstrated to exhibit excellent dc performance.…”