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Title: Novel vertical silicon photodiodes based on salicided polysilicon trenched contacts

The classical concept of silicon photodiodes comprises of a planar design characterized by heavily doped emitters. Such geometry has low collection efficiency of the photons absorbed close to the surface. An alternative, promising, approach is to use a vertical design. Nevertheless, realization of such design is technologically challenged, hence hardly explored. Herein, a novel type of silicon photodiodes, based on salicided polysilicon trenched contacts, is presented. These contacts can be prepared up to 10 μm in depth, without showing any leakage current associated with the increase in the contact area. Consequently, the trenched photodiodes revealed better performance than no-trench photodiodes. A simple two dimensional model was developed, allowing to estimate the conditions under which a vertical design has the potential to have better performance than that of a planar design. At large, the deeper the trench is, the better is the vertical design relative to the planar (up to 10 μm for silicon). The vertical design is more advantageous for materials characterized by short diffusion lengths of the carriers. Salicided polysilicon trenched contacts open new opportunities for the design of solar cells and image sensors. For example, these contacts may passivate high contact area buried contacts, by virtue of the conformity ofmore » polysilicon interlayer, thus lowering the via resistance induced recombination enhancement effect.« less
Authors:
 [1] ;  [2] ;  [3] ;  [1]
  1. Department of Chemical Engineering, Technion, Haifa (Israel)
  2. (Israel)
  3. TowerJazz Ltd. Migdal Haemek (Israel)
Publication Date:
OSTI Identifier:
22493001
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 14 SOLAR ENERGY; ABSORPTION; CARRIERS; DIFFUSION LENGTH; DOPED MATERIALS; EFFICIENCY; LEAKAGE CURRENT; PHOTODIODES; PHOTONS; RECOMBINATION; SENSORS; SILICON; SOLAR CELLS; TWO-DIMENSIONAL CALCULATIONS