The comparison of electrical and metallurgical properties of vacuum-evaporated Ge/Pd(Zn) and Au/Pd(Zn) contact metallizations to moderately doped p-type InGaP epitaxial layers (p ≈ 2 × 1018 cm-3) is presented. The Pd/Zn/Pd/Ge contacts exhibited Ohmic behaviour already from 400°C and their specific contact resistance dropped to 4 × 10-5 Ω cm2 when annealed at 490°C. Cross-sectional transmission electron microscopy and energy dispersive X-ray spectrometry demonstrated that a relatively sharp and nonspiking contact-InGaP interface has still been preserved at this high temperature. On the other hand, regardless of the excellent electrical properties (ρc= 5 × 10-6 Ω cm2 at 490°C) of the Pd/Zn/Pd/Au contacts, strong metallurgical reactions at the contact-InGaP interface at temperatures ≥450°C resulted in an extensive decomposition and melting of the interface area with deep protrusions into the InGaP.
|Number of pages||6|
|Journal||Physica Status Solidi (A) Applied Research|
|Publication status||Published - Mar 1 2001|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics