One-Dimensional Localization and Interaction Effects in Narrow (0.1-μm) Silicon Inversion Layers

Abstract

present case, the ionization energy of the Hg 6s 2 valence electrons is 1.4 eV higher than that of the Cd 5s 2 . It should further be noted that the work in the early 1960's showed 2 that both the decrease of E g to zero and the high electron mobilities are associated with the metal s states of the conduction band decreasing in energy with increasing Hg content until they mix with thep states to form the valence-band maximum. We thus identify three phenomena (the breakdown of VCA, E g going to zero, and high electron mobility) as resulting from the Hg 6s 2 atomic levels being significantly below the Cd 5s 2 levels.Hg^^Cd^Te is perhaps the most promising material available for photodetection throughout the infrared, yet it has not been widely exploited. This may be because of difficulties in growing and handling the material 2 ; we suggest that this also results from the "s shift" (i.e., selectivity increasing the bonding energy of the Hg valence s levels, which weakens the Hg-Te bond and leads to the difficulties mentioned above).It is our hope that this paper will stimulate work to test our suggestions. Such work is greatly needed, both for fundamental understanding and to guide (and reduce the cost of) practical work.The conductance of narrow (0.1-jum) silicon inversion layers has been measured at low temperatures. A divergent, nonmetallic decrease of conductance is observed below 30 K, in excellent quantitative agreement with the combined theories of weak localization and interaction effects in their one-dimensional form, if one assumes parameters comparable to those observed in wide (two-dimensional) inversion layers. In this novel experimental system both localization and interaction effects are present and comparable in size.

Disordered electronic systems

“…More recent and extensive work by White, Tinkham, Skocpol, and Flanders (1982), Masden and Giordano (1982), Skocpol, Jackel, Hu, Howard, and Fetter (1982), Wheeler, Choi, Goel, Wisnieff, and Prober (1982), and Santhanam, Wind, and Prober (1984) For a wire of cross section A, we have seen from Eqs.…”

Electrons in Silicon Microstructures

“…In this section, we describe new experiments with MOSFETs having gates of increased geometrical complexity in which spatially localized voltage measurements along narrow channels are made on length scales of 100 nm. These devices are otherwise similar to those described earlier (6)(7)(8)(9). Figure 2A is a micrograph of a 50-,im square region on a silicon wafer containing eight different implahted contacts and their associated metal leads.…”

Microfabrication as a Scientific Tool

“…These in turn serve as selfaligning masks that protect narrow channels during reactive ion etching (through the unprotected oxide and into the silicon substrate). Figure 4 shows the resulting structure of parallel narrow (1000 A) pedestals which confine the electron inversion layers at the oxide-silicon interface to the same width as the gate (24). Our experiment involves measuring the conductance from source to drain of these channels at low temperatures.…”