Platinum intermetallic resistors for GaAs-based circuits

A simple technique for making intermetallic resistors of sheet resistance around 25 Ω/□ is described. The resistors were formed by reacting a 300 Å film of platinum with underlying GaAs to completion. PtGa, PtGa2 and PtAs2 phases were identified in the temperature range of 450°C to 550°C investigated. The temperature coefficient of resistivity was of the order of +9.2 × 10-4°C-1 at 25°C and the resistors appeared to be stable up to current densities of 105 A/cm2. © 1985, The Institution of Electrical Engineers. All rights reserved.