Modification of metal-InGaAs Schottky barrier behaviour by atomic layer deposition of ultra-thin Al2O3 interlayers

作者：Chauhan Lalit^*; Gupta Suman; Jaiswal Piyush; Bhat Navakanta; Shivashankar S A; Hughes G

来源：Thin Solid Films, 2015, 589: 264-267.

DOI：10.1016/j.tsf.2015.05.046

• High-k dielectric
• Sulphur passivation
• Indium gallium arsenide
• Current-voltage measurement
• Schottky barrier height
• Interface formation
• Atomic layer deposition

The effect of inserting ultra-thin atomic layer deposited Al2O3 dielectric layers (1 nm and 2 nm thick) on the Schottky barrier behaviour for high (Pt) and low(Al) work function metals on n- and p-doped InGaAs substrates has been investigated. Rectifying behaviour was observed for the p-type substrates (both native oxide and sulphur passivated) for both the Al/p-InGaAs and Al/Al2O3/p-InGaAs contacts. The Pt contacts directly deposited on p-InGaAs displayed evidence of limited rectification which increased with Al2O3 interlayer thickness. Ohmic contacts were formed for both metals on n-InGaAs in the absence of an Al2O3 interlayer, regardless of surface passivation. However, limited rectifying behaviour was observed for both metals on the 2 nm Al2O3/n-InGaAs samples for the sulphur passivated InGaAs surface, indicating the importance of both surface passivation and the presence of an ultra-thin dielectric interlayer on the current-voltage characteristics displayed by these devices.

• 出版日期2015-8-31