Net carrier density present near the silicon-oxide
interface may constitute an important acceptance requirement. Where there is
not significant compensation by impurities of the opposite conductivity type,
the material resistivity may be determined from this carrier density using SEMI
MF723.
Flatband voltage is an important parameter in the
manufacture of MOS devices. Its value is dependent on the work function
difference between the silicon and the metal field plate, interface trapped
charge, and fixed or trapped charge distributed within the oxide. It can be an
indicator of anomalies in these values.
Instability of the flatband voltage of an MOS structure
subjected to voltage stress at elevated temperatures is a measure of the mobile
ionic charge density within the oxide. Most device applications require that
mobile ionic charge be minimized.
The presence of unwanted subsurface p-n junctions may have
deleterious effects on device operation.
This Test Method may be employed for qualification of
furnaces or other semiconductor device-processing equipment where such
qualification depends on the determination of contamination resulting from high
mobile ionic charge density.
This Test Method covers measurement of metal-oxide-silicon
(MOS) structures for flatband capacitance, flatband voltage, average carrier
density within a depletion length of the semiconductor-oxide interface,
displacement of flatband voltage after application of voltage stress at
elevated temperatures, mobile ionic charge contamination, and total fixed
charge density. Also covered is a procedure for detecting the presence of p-n
junctions in the subsurface region of bulk or epitaxial silicon.
Referenced SEMI Standards (purchase separately)
SEMI M59 — Terminology for Silicon Technology
SEMI MF576 — Test Method for Measurement of Insulator
Thickness and Refractive Index on Silicon Substrates by Ellipsometry
SEMI MF723 — Practice for Conversion Between Resistivity
and Dopant or Carrier Density for Boron-Doped, Phosphorus-Doped, and
Arsenic-Doped Silicon
Revision History
SEMI MF1153-1110 (Reapproved 0222)
SEMI MF1153-1110 (Reapproved 1015)
SEMI MF1153-1110 (technical revision)
SEMI MF1153-1106 (technical revision)
SEMI MF1153-92 (Reapproved 2002) (first SEMI publication)
