Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-05T05:14:05.700Z Has data issue: false hasContentIssue false

Effects of Very High Workfunction Metals or Metal Alloys (NiCr) on High Switching Speed, HV Schottky Diodes for Mixed Signal or RF ASIC

Published online by Cambridge University Press:  25 August 2020

J. Pan*
Affiliation:
Advanced Technology Laboratory, Northrop Grumman Corporation, 1212 Winterson Road, Linthicum, MS 3A13, Maryland, 21090, U.S.A.
A. Gaibrois
Affiliation:
Advanced Technology Laboratory, Northrop Grumman Corporation, 1212 Winterson Road, Linthicum, MS 3A13, Maryland, 21090, U.S.A.
M. Marripelly
Affiliation:
Advanced Technology Laboratory, Northrop Grumman Corporation, 1212 Winterson Road, Linthicum, MS 3A13, Maryland, 21090, U.S.A.
J. Leung
Affiliation:
Advanced Technology Laboratory, Northrop Grumman Corporation, 1212 Winterson Road, Linthicum, MS 3A13, Maryland, 21090, U.S.A.
S. Suko
Affiliation:
Advanced Technology Laboratory, Northrop Grumman Corporation, 1212 Winterson Road, Linthicum, MS 3A13, Maryland, 21090, U.S.A.
M. Lee
Affiliation:
Advanced Technology Laboratory, Northrop Grumman Corporation, 1212 Winterson Road, Linthicum, MS 3A13, Maryland, 21090, U.S.A.
T. Knight
Affiliation:
Advanced Technology Laboratory, Northrop Grumman Corporation, 1212 Winterson Road, Linthicum, MS 3A13, Maryland, 21090, U.S.A.
Get access

Abstract

For high switching speed HV Schottky diodes, with very high work function metal and extremely lightly doped epi, the built-in potential may be too high for thermionic emission to occur, when the applied external voltage is quite low (near VF = 0.07V). If the epi is lightly doped p type, the built-in potential (VBuilt-in: potential difference between the metal and silicon Fermi levels) is 1.0V (measured with CV). If the external bias is 0.1V, near the measured VF, it is not enough to overcome the built-in potential for thermionic emission as illustrated. It is likely that in addition to thermionic emission, tunnelling and diffusion currents also contribute to the total HV Schottky diode forward current. TCAD simulation of HV Schottky diodes with N+ guard bands suggests the potential barrier and electric fields at the Schottky junction are relatively high for thermionic emission to occur, when external bias V ≈ VF. In this paper we report HV Schottky diodes fabricated with various metals, metal alloys and epitaxial films. Metal work functions and epi doping profiles are extracted with high frequency Capacitance-Voltage (CV) technique. 150V of breakdown voltage and very low forward voltage (VF = 0.07V) are demonstrated. The measured data indicate very high work function metal or metal alloy is needed to achieve high switching speed and low forward voltage.

Type
Articles
Copyright
Copyright © Materials Research Society 2020

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Mistele, D., 2014 IEEE 28-th Convention of Electrical and Electronics Engineers in Israel.Google Scholar
Vukovic, J. H., IEEE CAS 2005 Proceedings International Semiconductor Conference, 2005.Google Scholar
Cordes, L. F., General Electric Corporate Research Development, PESC 74 RECORD - 205.Google Scholar
Pan, J., Materials Research Society Symp. Proc,Vol.745, pp.55-60.Google Scholar
Sze, S. M., “Physics of Semiconductor Devices”, 1981 John Wiley and Sons.Google Scholar
Lam, E. W., Electronics 2015, 4, 586-613; doi:10.3390/electronics4030586Google Scholar