P. Schuitemaker

Bio: P. Schuitemaker is an academic researcher from University of Sheffield. The author has contributed to research in topics: Double heterostructure & Heterojunction bipolar transistor. The author has an hindex of 1, co-authored 2 publications receiving 27 citations.

InP/InGaAs double heterostructure bipolar transistors grown by MBE

Abstract: Double heterostructure bipolar transistors have been fabricated on InP/InGaAs MBE material. Current gains of up to 80 have been observed in the emitter-up configuration. The devices were fabricated using two diffusion techniques and selective etching to contact the base.

Progress on InP /InGaAs(P) heterojunction bipolar transistors

Abstract: Preparation of lattice matched InP/InGaAs(P) heterojunctions was first reported by Antypas et all in 1972. Initially research efforts were mainly concentrated on optical devices. In recent years three-terminal InP/InGaAs(P) heterojunction bipolar transistors (HBT's), for microwave and digital applications, have gained more interest. Several laboratories have reported HBT's fabricated by LPE techniques but these were not optimised. More recently devices grown by MBE and CBE have been demonstrated in the InP/ InGaAs system. This paper is concerned with discussing the intrinsic advantages to be gained by fabricating HBT's in this material system and progress attained to date is reviewed.

High barrier height Au/n-type InP Schottky contacts with a POxNyHz interfacial layer

Abstract: A new insulation film, PO x N y H z , has been fabricated on n -InP substrate surface using vapor transport technique for use as an interfacial layer on n -InP Schottky contact devices. This interfacial layer is obtained by reaction of the deposited film with the substrate surface. It is stable and moisture insensitive. The capacitance voltage and current voltage characteristics are determined at various temperatures. Temperature dependence of ideality factor and apparent barrier height is observed. The Richardson plot gave a good straight line. At room temperature, the ideality factor is about 1.09; the apparent and true barrier heights evaluated from extrapolated forward saturation current and from Richardson plot ln ( I 0 T 2 ) vs 10 3 T respectively, are found to be equal to 0.80 and 0.39 eV; the reverse current density is found to be sufficiently low (6.4·10 −8 A / cm 2 at IV). The characteristics of the prepared Schottky device are analyzed.

High‐barrier height Schottky diodes on N‐InP by deposition on cooled substrates

Abstract: Ultrahigh barrier height (φB=0.96 eV) Schottky contacts to n‐InP, without an intentionally grown interficial oxide, were formed using metal deposition on a substrate cooled to as low as 77 K [low temperature (LT)]. φB = 0.46–0.52 eV for diodes deposited at room temperature (RT=300 K) agree well with previously published results, and give an ideality factor near unity. For the diodes deposited at LT=77 K, the leakage current density (J0) was reduced by more than 6–7 orders of magnitude with respect to the RT diodes. The φB for the LT diodes was increased from 0.48 to 0.96 eV for Pd metal and from 0.51 to 0.85 eV for Au metal, respectively. An alteration of the metal‐induced interface states, inhibition of surface segregation of the released In and P atoms, and very uniform metal coverage may be responsible for the distinct differences between the RT and LT diodes.

MIS diodes on n-InP having an improved interface

Abstract: Metal-insulator-InP diodes with Al, Ni, Au and Pd Schottky contacts were fabricated using improved surface passivation techniques. The current-voltage (I–V) characteristics and the barrier height data indicate that a thin layer of thermal oxide between the metal-InP interface and a proximity cap protection during the RTA ohmic contact annealing improve the surface properties, as confirmed by deep level transient spectroscopy (DLTS), no surface trap being detected. The chemical reactivity of the metal with oxide and n-InP is important to the formation of Schottky barriers. The reactive metals Al and Ni gave a low barrier height due to the reduction of oxide and reaction with InP. Nonreactive metals Au and Pd gave a high barrier height. The modified thermionic emission (TE) theory and thermionic field emission (TFE) theory can be used to explain the conduction mechanisms on Ni and Au MIS diodes. The Pd MIS diode exhibited an excess current component at low forward bias due to surface states which predominate at low temperature.

Double-heterojunction bipolar transistors in InP/GaInAs grown by metal organic chemical vapour deposition

Abstract: Double-heterojunction bipolar transistor structures in InP/GaInAs have been grown by low-pressure metal organic chemical vapour deposition. Good control of the Zn dopant in the GaInAs base layer was achieved, and devices with current gains up to 300 at current densities of 1.4kA/cm2 have been demonstrated.