Structural and electrical-physical properties of the ohmic contacts based on palladium to n⁺ -n-n⁺⁺ -n⁺⁺⁺ -InP

Presented in this paper are experimental data on structural properties of contact metallization and temperature dependence of the specific contact resistance for ohmic contacts Au–Ti–Pd–n⁺-InP and Au–Ti–Ge–Pd-n⁺-InP prepared using the method of successive thermal evaporation of metals in oil-free vacuum in one process cycle onto the n⁺-n-n⁺⁺-n⁺⁺⁺-InP epitaxial structure heated to 300 °C. It has been theoretically and experimentally shown that within the temperature range 250…380 K the current transport mechanism in the ohmic contacts Au–Ti–Pd–n⁺-InP is thermal-field one, and in the ohmic contacts Au–Ti–Ge–Pd-n⁺-InP it is caused by conductivity along metal shunts linked with dislocations. According to the X-ray diffraction data, the density of these dislocations in the near-contact InP area is ~10⁹ cm⁻²

Ohmic contacts based on Pd to indium phosphide Gunn diodes

Experimental data on manufacturing the ohmic contacts Au–Ti–Pd–n⁺-InP, formed using vacuum deposition of metal onto a heated to 300 °C substrate representing an epitaxial n⁺-n-n⁺⁺-n⁺⁺⁺-InP structure. The specific contact resistance measured at room temperature was about 7·10⁻⁵ Ohm·cm². Voltage-current characteristics within the temperature range 110 to 380 K are linear. Gunn diodes with such contacts, which were made as a straight mesa-structure in a pulsed mode (pulse duration of 100 ns, pulse ratio of 1000, operating current of 2.2 A), generated the microwave power ~10 mW in the V-band