Highly transmittive semiconductor base for ballistic electron emission microscopy

✍ Scribed by Heer, R.; Smoliner, J.; Strasser, G.; Gornik, E.

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 140 KB
• Volume: 27
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(199905/06)27:5/6<517::aid-sia499>3.0.co;2-4

✦ Synopsis

In this work we introduce a molecular beam epitaxy (MBE)-grown InAs layer as base in ballistic electron emission spectroscopy/microscopy (BEES/BEEM). Compared to the commonly used thin metal Ðlm as base, the transmission coefficient and the attenuation length can be enhanced by more than one order of magnitude. At low temperatures (T = 100 K), a passivated InAs layer yields an attenuation length of the order of 70-90 nm, instead of the 5 nm obtained on Au Ðlms. This feature makes InAs a promising new base material for BEEM. To clarify the mechanism of this behaviour, temperature-dependent BEEM studies on InAs-GaAs heterostructures were performed. Unlike samples with metal base layers, it is found that the transmission coefficient of the InAs base decreases with decreasing temperature. In addition, a strongly increasing conduction band o †set at the InAs/GaAs interface with decreasing temperature is observed.