Novel High Speed Silicon Photodetector With Tunnel-barrier Layers.

Abstract

We demonstrate a new type of high speed silicon photodetector having a symmetric Metal/Tunnel-oxide/Silicon/Tunnel-oxide/Metal structure. A schematic cross-section of the device is illustrated in Figure (1). A silicon dioxide layer of approximately 45-60 angstroms is thermally grown on a lightly-doped P-type silicon wafer. A top view (Figure (2)) shows the aluminum electrodes forming an interdigital pattern over the relatively large circular active region (150 micrometers in diameter), while keeping junction capacitance small so that it does not limit the response speed of the detector (1-3). Both electrodes and the gaps are 5 micrometers wide.