Frequency Response of Metal–Semiconductor Structures With Thin-Films Sapphire Interlayer by ALD Technique

MIS-type Al/Al
₂
O
₃
/p-Si structures were fabricated to identify its admittance analysis through capacitance/conductance versus logarithmic frequency (
${C} / {G}$
–
${V}$
–
${f}$
) data in the 1 kHz–5 MHz and ±3 V ranges at room temperature. Admittance measurements determine the surface states (
${N}_{\text{ss}}$
) and these states occurred at M/S interlayer arise as a result of high capacitance and conductance values at low frequencies. This is also explained by adequacy of tracking ac signal by
${N}_{\text{ss}}$
at lower frequencies. In consequence with
${N}_{\text{ss}}$
presence, a peak turns up or becomes visible at the normalized parallel conductance versus logarithm of frequency [
${G}_{\text{p}} / \omega -$
ln(
${f}$
)] plot under various biases. In the energy range of (
$0.17- {E}_{\text{v}}$
)–(
$0.67- {E}_{\text{v}}$
),
${N}_{\text{ss}}$
and their life/relaxation time (
$\tau $
) values vary from
$4.95\times 10^{12}$
to
$7.42\times 10^{11}$
eV
$^{-1}\cdot \text{cm}^{-2}$
and from
$7.85\times 10^{-5}$
to
$1.05\times 10^{-6}$
s, respectively.