Series impedance of GaAs planar Schottky diodes operated to 500 GHz

Author

Bhaumik, Kaushik ; Gelmont, Boris ; Mattauch, Robert J. ; Shur, Michael

Author_Institution

Sch. of Electr. Eng., Cornell Univ., Ithaca, NY, USA

Volume

40

Issue

5

fYear

1992

fDate

5/1/1992 12:00:00 AM

Firstpage

880

Lastpage

885

Abstract

The author discusses the impact of ohmic contacts on the series impedance of a GaAs cylindrical planar Schottky diode. The expression for the high-frequency impedance of an annular ohmic contact is developed using a novel transmission line model. This formulation is used to ascertain the contribution of the ohmic contact impedance to the overall device series impedance at both DC and 500 GHz. Diode impedance characterization indicates that the ohmic contact impedance makes a small contribution to the series impedance in comparison to that of the other components, both at DC and submillimeter wavelengths. Hence, the dimensions of the contact pads can be scaled down significantly without any appreciable increase in series impedance but with a decrease in the parasitic pad-to-pad capacitance. Finally, this modeling establishes theoretical guidelines regarding the allowable limits for specific contact resistance in small geometry diodes, so that the device I -V characteristics are not significantly altered as a result of the ohmic contact impedance

Keywords

III-V semiconductors; Schottky-barrier diodes; contact resistance; gallium arsenide; ohmic contacts; semiconductor device models; solid-state microwave devices; submillimetre wave devices; 500 GHz; DC; GaAs; I-V characteristics; THF; annular ohmic contact; contact resistance; high-frequency impedance; modeling; ohmic contact impedance; planar Schottky diodes; series impedance; small geometry diodes; submillimeter wavelengths; transmission line model; Contact resistance; Gallium arsenide; Guidelines; Impedance; Ohmic contacts; Parasitic capacitance; Planar transmission lines; Schottky diodes; Solid modeling; Transmission line theory;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.137393

Filename

137393