The e †ect of annealing in the temperature range 100È300 ¡C with steps of 100 ¡C for 5 min on characteristic parameters, especially series resistance, of nearly ideal (D1) and ideal (D2) Ti/n-GaAs Schottky barrier diodes (SBDs) has been investigated. Both Ti/n-GaAs SBDs have shown thermal stability up to 300 ¡C annealing. It can be said that the interfacial layer thickness of sample D1 is too thin to hinder thermal stability. The ideality factor and barrier height of samples D1 and D2 have been found to be 1.05 and 0.76 eV and 1.06 and 0.75 eV at 300 ¡C respectively, while 1.08 and 0.64 eV and 1.01 and 0.67 eV for their as-deposited samples, respectively. The series resistance values have decreased with increasing annealing temperature. This has been attributed to reduction of the native oxide layer by the metal Ti. It has been concluded that the annealing to a given temperature has improved the electrical characteristics of both Ti/n-GaAs Schottky contacts due to chemical reactions between substrate and the reactive metals and the native oxide.