Analysis of current–voltage–temperature characteristics and T0 anomaly in Cr/ n-GaAs Schottky diodes fabricated by magnetron sputtering technique

Abstract

We have fabricated two groups of Cr/ n-GaAs Schottky diodes (SDs) by magnetron sputtering technique to determine whether T 0 anomaly varies in similarly fabricated SDs or not. Firstly, the first group diodes were inserted into a vacuum chamber to form the Schottky contacts, then the second group diodes which are held in the clean room medium for 3 h before Schottky metal deposition. The current–voltage ( I– V) characteristics of three diodes (the dots of the sample CrD1) from the first group and two diodes (the dots of the sample CrD2) from the second group were measured in temperature range of 60–320 K. The barrier heights increased with increasing temperature in range of 60–160 K, and did not changed in range of 160–320 K. Ideality factory value decreased with increasing temperature in range of 60–160 K and changed between 1.05 and 1.10 in range of 160–320 K. T 0 anomaly values were calculated from straight lines fitted to nT′– T plots. The fits to the experimental values of nT– T plots are parallel to the ideal Schottky contact line, especially for the dots (Schottky diodes) of the sample CrD1. T 0 anomaly values for the dots of the sample CrD1 were obtained as 13.9, 11.20 and 13.31 K; and the values of 19.74 and 19.20 K was obtained for the dots of the sample CrD2. It has been concluded that the T 0 anomaly values for the similarly fabricated diodes (the dots of the sample CrD1 or the CrD2) are almost very close to each other within the margins of experimental error.