Improving the X-ray radiation tolerance of the analog ICs by using OCTO layout style

Abstract

This paper investigates and compares experimentally the total ionizing dose (TID) effects in the main analog parameters of the fully depleted (FD) OCTO Silicon-On-Insulator (SOI)n-type Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) (OSM), that presents an octagonal gate geometry, versus its conventional (rectangular gate geometry) counterpart (CSM). The main analog parameters taken into account in this study are the drain current in saturation region (I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DSsat</inf> ), the maximum transconductance (g <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m-max</inf> ), the transconductance (g <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> ) over the drain current (I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</inf> ) ratio (g <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> /I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</inf> ), the unity voltage gain frequency (f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> ), intrinsic voltage gain (A <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</inf> ) and Early voltage (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">EA</inf> ). This work demonstrates that OCTO layout style achieved the same relative variation due the TID effects as the conventional for the main analog parameters, but keeping the higher electrical performance related to the LCE and PAMDLE effects. In addition the OSM had a higher tolerance in terms of g <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m-max</inf> , I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DSsat</inf> and V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">EA</inf> relative variation and f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> and A <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</inf> performance in strong inversion regime.