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Title: BUSFET - A Novel Radiation-Hardened SOI Transistor

Abstract

The total-dose hardness of SOI technology is limited by radiation-induced charge trapping in gate, field, and SOI buried oxides. Charge trapping in the buried oxide can lead to back-channel leakage and makes hardening SOI transistors more challenging than hardening bulk-silicon transistors. Two avenues for hardening the back-channel are (1) to use specially prepared SOI buried oxides that reduce the net amount of trapped positive charge or (2) to design transistors that are less sensitive to the effects of trapped charge in the buried oxide. In this work, we propose a new partially-depleted SOI transistor structure that we call the BUSFET--Body Under Source FET. The BUSFET utilizes a shallow source and a deep drain. As a result, the silicon depletion region at the back channel caused by radiation-induced charge trapping in the buried oxide does not form a conducting path between source and drain. Thus, the BUSFET structure design can significantly reduce radiation-induced back-channel leakage without using specially prepared buried oxides. Total dose hardness is achieved without degrading the intrinsic SEU and dose rate hardness of SOI technology. The effectiveness of the BUSFET structure for reducing total-dose back-channel leakage depends on several variables, including the top silicon film thickness and dopingmore » concentration and the depth of the source. 3-D simulations show that for a doping concentration of 10{sup 18} cm{sup {minus}3} and a source depth of 90 nm, a silicon film thickness of 180 nm is sufficient to almost completely eliminate radiation-induced back-channel leakage. However, for a doping concentration of 3x10{sup 17} cm{sup {minus}3}, a thicker silicon film (300 nm) must be used.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
Sponsoring Org.:
US Department of Energy (US)
OSTI Identifier:
9468
Report Number(s):
SAND99-0323J
TRN: US0103131
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Journal Article
Resource Relation:
Journal Name: IEEE Transactions on Nuclear Science; Other Information: Submitted to IEEE Transactions on Nuclear Science; PBD: 20 Jul 1999
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; DESIGN; DOSE RATES; RADIATION HARDENING; FIELD EFFECT TRANSISTORS; SILICON; THIN FILMS; DOPED MATERIALS; LEAKAGE CURRENT

Citation Formats

Schwank, J.R., Shaneyfelt, M.R., Draper, B.L., and Dodd, P.E.. BUSFET - A Novel Radiation-Hardened SOI Transistor. United States: N. p., 1999. Web. doi:10.1109/23.819158.
Schwank, J.R., Shaneyfelt, M.R., Draper, B.L., & Dodd, P.E.. BUSFET - A Novel Radiation-Hardened SOI Transistor. United States. doi:10.1109/23.819158.
Schwank, J.R., Shaneyfelt, M.R., Draper, B.L., and Dodd, P.E.. Tue . "BUSFET - A Novel Radiation-Hardened SOI Transistor". United States. doi:10.1109/23.819158. https://www.osti.gov/servlets/purl/9468.
@article{osti_9468,
title = {BUSFET - A Novel Radiation-Hardened SOI Transistor},
author = {Schwank, J.R. and Shaneyfelt, M.R. and Draper, B.L. and Dodd, P.E.},
abstractNote = {The total-dose hardness of SOI technology is limited by radiation-induced charge trapping in gate, field, and SOI buried oxides. Charge trapping in the buried oxide can lead to back-channel leakage and makes hardening SOI transistors more challenging than hardening bulk-silicon transistors. Two avenues for hardening the back-channel are (1) to use specially prepared SOI buried oxides that reduce the net amount of trapped positive charge or (2) to design transistors that are less sensitive to the effects of trapped charge in the buried oxide. In this work, we propose a new partially-depleted SOI transistor structure that we call the BUSFET--Body Under Source FET. The BUSFET utilizes a shallow source and a deep drain. As a result, the silicon depletion region at the back channel caused by radiation-induced charge trapping in the buried oxide does not form a conducting path between source and drain. Thus, the BUSFET structure design can significantly reduce radiation-induced back-channel leakage without using specially prepared buried oxides. Total dose hardness is achieved without degrading the intrinsic SEU and dose rate hardness of SOI technology. The effectiveness of the BUSFET structure for reducing total-dose back-channel leakage depends on several variables, including the top silicon film thickness and doping concentration and the depth of the source. 3-D simulations show that for a doping concentration of 10{sup 18} cm{sup {minus}3} and a source depth of 90 nm, a silicon film thickness of 180 nm is sufficient to almost completely eliminate radiation-induced back-channel leakage. However, for a doping concentration of 3x10{sup 17} cm{sup {minus}3}, a thicker silicon film (300 nm) must be used.},
doi = {10.1109/23.819158},
journal = {IEEE Transactions on Nuclear Science},
number = ,
volume = ,
place = {United States},
year = {Tue Jul 20 00:00:00 EDT 1999},
month = {Tue Jul 20 00:00:00 EDT 1999}
}