Researchers working in part at SSRL Beam Lines 8-1 and 10-1 recently characterized the band offsets in a promising semiconductor material that could lead to smaller and faster electronic devices of the future. The results are published in the September 13, 2007 edition of Applied Physics Letters.

The famous Moore's law, which has held true for more than 40 years, says computing power—i.e., the number of transistors on a chip—roughly doubles every 18 months. But traditional electronics using metal-oxide semiconductors are nearing chip design performance limits because the thinner and smaller the components become, the more electric current tends to leak from them, making them inefficient. To keep on top of the curve for smaller and faster electronic devices, new semiconductors must be developed that overcome the limitations of current leakage due to increasingly thin insulating layers.

Using photoemission spectroscopy, Niti Goel of Intel and SSRL scientist Yun Sun successfully measured the alignment of energy bands, or band offsets, between the high-dielectric constant materials lanthanum aluminate (LaAlO₃) and the semiconductor substrate indium gallium arsenide (In_0.53Ga_0.47As) for potential use as ultra-thin insulators. Such measurements are important for engineering efficient semiconductors that will work on the ever shrinking size-scales needed for advanced electronic devices.

N. Goel, W. Tsai, C.M. Garner, Y. Sun, P. Pianetta, M. Warusawithana, D.G. Schlom, H. Wen, C. Gaspe, J.C. Keay, et. al. (2007) Band offsets between amorphous LaAlO3 and In0.53Ga0.47As. Applied Physics Letters, 91, no.11, p.113515

To learn more about this research see the full scientific highlight at:
http://www- ssrl.slac.stanford.edu/research/highlights_archive/highk_dielectrics.html