High-performance Au/Ti/Ge/Pd ohmic contacts on n+-In0.5Ga0.5P have been fabricated for the first time. Using an n+-In0.5Ga0.5P epitaxial layer grown by low pressure metalorganic chemical vapor deposition (LP-MOCVD) with a Si dopant concentration of about 2 × 1018 cm-3, the minimum specific contact resistivity is as low as 1.2 × 10-5 Ω·cm2, which is much lower than that of AuGeNi contacts after rapid thermal annealing at 400°C for 60 s. The thermal stability of the Au/Ti/Ge/Pd system is significantly higher than that of conventional AuGeNi due to the introduction of the Ti barrier layer. Many holes and islands are observed on the surfaces of samples annealed at high temperature. The outdiffusion of P from the decomposed In0.5Ga0.5P substrate and agglomeration of Pd and Ge are the primary causes of contact degradation.
|Number of pages||4|
|Journal||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|Issue number||4 A|
|State||Published - 1 Apr 1996|
- Ohmic contact
- n-type InGaP