P–N junction and metal contact reliability of SiC diode in high temperature (873 K) environment

•First report on I–V characteristic of Ni metallized SiC diode up to 873 K.•Die attachment process for high temperature (873 K) application of SiC diode.•Comparison of electrical properties of Ni and Pt metal contact at high temperature.•Aging effect of diode on the metal contact at high temperature.

This paper reports the high temperature test results of SiC p–n junction diode up to 873 K. No significant change in diode series resistance (Rs) and a diode ideality factor of 1.02 were confirmed in air. We used the 4H-SiC diode which had a contact pad area of 300 μm × 300 μm and a junction area of 220 μm × 220 μm. Ohmic contact on both p and n (i.e. front and back) sides were made by Ni, because nickel silicide (NiSi) provides good ohmic contact for high temperature applications. The electrical contact pads of the SiC diode were made by sputter-depositing Ni or Pt on the NiSi ohmic contact. High temperature aging tests at 673 K, 773 K and 873 K were carried out in air, and the forward current–voltage (I–V) characteristics of the SiC diodes were measured at different time intervals to observe change in the junction and series resistance. Stable p–n junction characteristic and constant series resistance were confirmed for the Pt-metalized diodes at 673 K, 773 K and 873 K. However, the Ni-metallized diodes showed marginal increase in series resistance due to the oxidation of Ni metal contacts.