Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-29T07:46:05.207Z Has data issue: false hasContentIssue false
  • English
  • Français

Fabrication of High Quality MOS Devices for Application in Hazardous Environments Based on RTP Gate Dielectrics with In Situ RTCVD of Polysilicon Gates

Published online by Cambridge University Press:  22 February 2011

B. Fröschle ,
H.P. Bruemmer ,
W. Lang ,
K. Neumeier  and
P. Ramm
B. Fröschle
Affiliation:
Fraunhofer-Institut für Festkörpertechnologie, Hansastraße 27 d, 8000 München 21, Germany
H.P. Bruemmer
Affiliation:
Consultant, Goßwinstr. 14, 8000 München 60, Germany
W. Lang
Affiliation:
Fraunhofer-Institut für Festkörpertechnologie, Hansastraße 27 d, 8000 München 21, Germany
K. Neumeier
Affiliation:
Fraunhofer-Institut für Festkörpertechnologie, Hansastraße 27 d, 8000 München 21, Germany
P. Ramm
Affiliation:
Fraunhofer-Institut für Festkörpertechnologie, Hansastraße 27 d, 8000 München 21, Germany
Get access

Abstract

Process modules for MOS gate fabrication were developed which can be completed subsequently in one RTP reactor: atmospheric process sequences for gate oxides and oxynitrides as well as low pressure chemical vapor deposition of polysilicon (RTCVD). Prior to the Rapid Thermal Oxidation (RTO), the wafers were treated with a Rapid Thermal Cleaning process (RTC) in H2/Ar ambient. After the desoxidation step the RTO was done in O2/H2/Ar followed by an anneal (RTA) for the gate oxide or a nitridation in NH3 (RTN) and reoxidation for the oxynitrides, respectively. The polysilicon gate electrode was fabricated either by RTCVD in situ or in a conventional furnace reactor. The two-step RTCVD process resulted in a very good thickness uniformity for the polysilicon layers of 3% (3mm from the edge). The influence of the process variations on breakdown field, fixed oxide charge, interface state density, flatband voltage, and threshold voltage of the different types of gate dielectrics was investigated. The charges and voltages were determined by LF-HF CV measurements. In order to characterize the radiation tolerance of electronic devices, radiation induced flatband and threshold voltage shifts as well as the build up of interface charges were determined. The irradiation was performed at a Co - 60 gamma source. Breakdown fields in the range of 19 MV/cm, interface state densities of less than 109 eV−1cm−2, and radiation induced threshold voltage shifts below 0.1 V after 1.5 Mrad(Si) were obtained.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 300: Symposium D1 – III-V Electronic and Photonic Device Fabrication and Performance , 1993 , 587
Copyright
Copyright © Materials Research Society 1993

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

REFERENCES

1. Ma, T.P. and Dressendorfer, P.V., in Ionizing Radiation Effects in MOS Devices and Circuits, edited by Ma, T.P. and Dressendorfer, P.V. (John Wiley, New York, 1989) pp. 35–43.Google Scholar
2. Iberl, F., Ramm, P. and Lang, W., Nucl. Inst. and Meth. B 64, 650 (1992).Google Scholar
3. Sedquick, T. O., Mat. Res. Soc. Symp. Proc. 92 (3), (1987).Google Scholar
4. Doolittle, L.R., Nucl. Inst. and Meth. B 15, 227(1986)Google Scholar
5. Freeman, R. and Holmes-Siedle, A.H. IEEE, Trans. Nucl. Sci., NS–25 (6), 1216 (1987)Google Scholar
6. Derbenwick, G.F. and Gregory, B.L., IEEE Trans. Nucl. Sci. NS–22 (6), 2151 (1975).Google Scholar
7. Neumeier, K. et al. in Nuklearhaertunq von Silizium-Bauelementen, Final Report T/RF 31/J 0033/ J 1319, Fraunhofer-Institut fOr Festk6rpertechnologie (1992) pp. 18–27.Google Scholar