Ohmic contacts formation on n-InP

Abstract

We have investigated the correlation between contact resistance, heat treatment, and micro structure in ohmic contacts on n-InP. The samples consisted of three different structures: 50 nm-Ni/200 nm-AuGe/n-InP, Au/100 nm-Pt/100 nm-Ti/50 nm-Ni/n-InP, and 200 nm-Au/100 nm-Pt/100 nm-Ti/ 50 nm-Ni/200 nm-AuGe/n-InP. After annealing the samples, depth profiles obtained by Auger electron spectroscopy and ion sputtering showed a tendency of the Ge to migrate from the Au-Ge alloy towards the Ni layer, as well as an accumulation of Ni at the semiconductor interface. A Ni-P phase is identified as being responsible for the ohmic character of the metal/InP interface. Specific contact resistivities were measured for the three different types of metallizations. We observed that the resistivity is sensitive to the annealing temperature and related to the amount of Ni at the metal/InP interface. The use of overlayers is suggested to avoid migration of the semiconductor components towards the contact surface.

Ballistic transport and surface scattering in (In,Ga)As-InP heterostructure narrow channels

“…that the Ti layer protected the Au layer from the alloying reaction that occurred between the Ni/AuGe layer and the heterostructure [26].…”

XPS and HAXPES analyses for pre-sputtered InP surface and InP/Pt interface

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] In the metal-semiconductor field-effect transistors (MESFETs), for example, the concentration of defects at the InP surface is thought to be very small compared to that of gallium arsenide (GaAs). [1][2][3] In the case of the hetero junction bipolar transistors combined with indium gallium arsenide (In x Ga 1−x As), InP is indispensable since it has both the wider bandgap than In x Ga 1−x As and the lattice constant matching to that of In x Ga 1−x As. [4][5][6][7][8][9][10][11] Regarding the electrode for these devices, platinum (Pt) is one of the most popular materials.…”