中国物理B ›› 2010, Vol. 19 ›› Issue (10): 107207-107207.doi: 10.1088/1674-1056/19/10/107207

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Effect of diode size and series resistance on barrier height and ideality factor in nearly ideal Au/n type-GaAs micro Schottky contact diodes

, R. K. Mamedov1, M. A. Yeganehx2, Sh. Rahmatallahpur3, A. Nozad3   

  1. (1)Faculty of Physics, Baku State University, Academic Zahid X@lilov Küç@si-23, AZ 1148, Iran; (2)Faculty of Physics, Baku State University, Academic Zahid X@lilov Küç@si-23, AZ 1148, Iran ; Material Research School, POB 55515196, Binab, Iran; (3)Material Research School, POB 55515196, Binab, Iran
  • 收稿日期:2010-03-31 修回日期:2010-04-29 出版日期:2010-10-15 发布日期:2010-10-15

Effect of diode size and series resistance on barrier height and ideality factor in nearly ideal Au/n type-GaAs micro Schottky contact diodes

M. A. Yeganeha)b),Sh. Rahmatallahpurb), A. Nozadb), and R. K. Mamedova)   

  1. a Faculty of Physics, Baku State University, Academic Zahid X?lilov K???esi-23, AZ 1148, Iran; b Material Research School, POB 55515196, Binab, Iran
  • Received:2010-03-31 Revised:2010-04-29 Online:2010-10-15 Published:2010-10-15

摘要: Small high-quality Au/n type-GaAs Schottky barrier diodes (SBDs) with low reverse leakage current are produced using lithography. Their effective barrier heights (BHs) and ideality factors from current--voltage (I--V) characteristics are measured by a Pico ampere meter and home-built I--V instrument. In spite of the identical preparation of the diodes there is a diode-to-diode variation in ideality factor and barrier height parameters. Measurement of topology of a surface of a thin metal film with atomic force microscope (AFM) shows that Au-n type-GaAS SD consists of a set of parallel-connected micro and nanocontacts diodes with sizes approximately in a range of 100--200 nm. Between barrier height and ideality factor there is an inversely proportional dependency. With the diameter of contact increasing from 5 μm up to 200 μm, the barrier height increases from 0.833 up to 0.933 eV and its ideality factor decreases from 1.11 down to 1.006. These dependencies show the reduction of the contribution of the peripheral current with the diameter of contact increasing. We find the effect of series resistance on barrier height and ideality factor.

关键词: Schottky barrier diodes, conducting probe-atomic force microscope, barrier height and ideality factor

Abstract: Small high-quality Au/n type-GaAs Schottky barrier diodes (SBDs) with low reverse leakage current are produced using lithography. Their effective barrier heights (BHs) and ideality factors from current–voltage (IV) characteristics are measured by a Pico ampere meter and home-built IV instrument. In spite of the identical preparation of the diodes there is a diode-to-diode variation in ideality factor and barrier height parameters. Measurement of topology of a surface of a thin metal film with atomic force microscope (AFM) shows that Au-n type-GaAS SD consists of a set of parallel-connected micro and nanocontacts diodes with sizes approximately in a range of 100–200 nm. Between barrier height and ideality factor there is an inversely proportional dependency. With the diameter of contact increasing from 5 μm up to 200 μm, the barrier height increases from 0.833 up to 0.933 eV and its ideality factor decreases from 1.11 down to 1.006. These dependencies show the reduction of the contribution of the peripheral current with the diameter of contact increasing. We find the effect of series resistance on barrier height and ideality factor.

Key words: Schottky barrier diodes, conducting probe-atomic force microscope, barrier height and ideality factor

中图分类号:  (Atomic force microscopy (AFM))

  • 68.37.Ps
68.55.-a (Thin film structure and morphology) 73.30.+y (Surface double layers, Schottky barriers, and work functions) 73.40.Ns (Metal-nonmetal contacts) 85.30.Hi (Surface barrier, boundary, and point contact devices) 85.40.Hp (Lithography, masks and pattern transfer)