| AVS 64th International Symposium & Exhibition | |
| Electronic Materials and Photonics Division | Tuesday Sessions |
| Session EM+NS-TuM |
| Session: | Nanostructures and Nanometer Films for Electronic and Photonic Devices |
| Presenter: | Fred Cadieu, Queens College of CUNY and Graduate Center of CUNY |
| Authors: | F.J. Cadieu, Queens College of CUNY and Graduate Center of CUNY J.S. Monaco, Queens College of CUNY L. Mourokh, Queens College of CUNY and Graduate Center of CUNY |
| Correspondent: | Click to Email |
Approximately 10 nm thick light sensing film structures have been fabricated by sequentially sputtering various metals in oxygen, then in argon, and then in oxygen again. The layers have been deposited onto heated silicon substrates to create a diffusion region. The layered thicknesses were calibrated by x-ray reflectivity measurements. The film layers, being mostly oxides, exhibit a high lateral resistivity so that the current path is through the film thickness between a grid of contacts deposited below and on top of the film structures. For such current, a high degree of light sensitivity, and voltage polarity sensitivity, has been observed.1 Analogous film structures have been fabricated using hafnium,2 titanium,2 and aluminum such that exposure to light causes large increases in currents for one voltage polarity, but little or no effect for the opposite polarity. The observed phenomenology has been shown to be consistent with a single-particle model based on the existence of interface states on the metal-oxide interfaces.2 The details of light sensitivity and current polarity sensitivity are dependent on the deposition temperatures and thicknesses of the film layers. Hafnium based interfaces respond repeatedly to light pulses with current pulses up to several hundred microamperes, while aluminum based interfaces can only respond repeatedly with current pulses up to several tens of microamperes.
1. F.J. Cadieu, Device with Light-Responsive Layers. US Patent No. 9,040,982.
2. F.J. Cadieu and Lev Murokh, Nanometer Thick Diffused Hafnium and Titanium Oxide Light Sensing Film Structures, World Journal of Condensed Matter Physics7, 36-45 (2017).