tesi R. Miscioscia.pdf - EleA@UniSA

132 Exceptions in morphology-mobility relationship
measured drain current from the gate leakage contribution and then
performing thermal analyses for our OTFTs.
3.4.4 Gate leakage-free results and thermal analysis
As an example, if we consider the output characteristics of a
PMMA 114nm gate insulator OTFT, by applying the Esseni
method[26][27] at the first order (eq. 5) an estimation of the channel
current can be extracted by algebraic means once measured directly IG
and ID.
eq. 5
Where the meaning of symbols has already been cleared in chapter
1. This approximation is physically consistent with the expected
behavior because has the ability to restore in experimental curves the
zero-crossing as required from the gate leakage-free condition. Thus,
the fitting of output characteristics with the ideal MOSFET model
becomes easier and simulated curves are very close to estimated Ich
ones (compare the square symbols, the blue stars and red continuos
line in figure 16 for VG=-16V).
By applying the extraction method to all the trans-characteristics
of considered transistors, we can repeat the mobility analysis which
for the sake of simplicity we reported in figure 17.