Eur. Phys. J. AP 14, 127-130 (2001)
https://doi.org/10.1051/epjap:2001147

Effect of substrate doping profile on C−V curves for thin MOS capacitors^*

Laboratoire d'Automatique et de Microélectronique (LAM), Université de Reims Champagne Ardenne, UFR Sciences, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2, France

Corresponding author: olivier.simonetti@univ-reims.fr

Received: 31 October 2000
Revised: 15 March 2001
Accepted: 15 March 2001
Published online: 15 May 2001

Abstract

We use a full quantum model of MOS (metal oxide semiconductor) structure to study the influence of a non-uniform doping profile of the substrate on the capacitance-voltage (C−V) behavior of the structure. For different “realistic” doping profiles, simulations are performed and compared to simulations with an uniform doping and to C−V measurements for samples with oxide thickness in the range [2−5 nm] [1]. In each case, we have extracted the oxide thickness that is found to be independent of the doping and the flat-band voltage which can be shifted up to 200 mV regarding the different profiles tested here. Moreover, below about 3 nm, the shape of the C−V simulation is more affected, which shows that the doping profile of the substrate has a great importance for an accurate C−V modeling of ultra-thin MOS structures.