La. Ragnarsson et al., Electrical characterization of interfacial reactions in ultrathin oxides during postmetalization anneal, J ELCHEM SO, 146(7), 1999, pp. 2637-2642
The chemical reduction of ultrathin oxides in aluminum-SiO2-silicon metal o
xide semiconductor (MOS) structures during post-metalization anneal was Stu
died by means of electrical measurements. This reduction is a possible way
of increasing the capacitance of the MOS device without necessarily increas
ing the leakage current and also without harming the electrical Si-SiO2 int
erface. This is accomplished by replacing part of the SiO2 with a compound
of higher permittivity. The reduction was found to be insensitive to (i) th
e substrate doping type, (ii) the oxidation ambient, (iii) the oxidation te
mperature, and (iv) the initial oxide thickness. It appears to be dependent
on the oxide quality. An accurate method of determining the thickness diff
erence between two dielectrics using capacitance-voltage measurements is al
so presented. (C) 1999 The Electrochemical Society. S0013-4651(98)11-045-5.
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