4.3.1 Effective Mass and Band
Edge Energy
In [47]
and [48]
the effective masses as well as the band edge energies of electrons and
holes for AlGaAs and InGaAs are given, respectively. The effective masses
of electrons and holes for Al_{y}Ga_{1y}As read
(36)

. 
(37)

The lattice temperature T_{L} [K] and Al mole fraction
y dependent E_{g} of Al_{y}Ga_{1y}As
reads:
(38)

(39)

(40)

(41)

, 
(42)

. 
(43)





















As described in Chapter 2 the current in a HEMT
channel is conducted in a strained quantum well. The effective conduction
band offset DE_{C eff} of the
unstrained bulk material described by the above models is changed due to
strain and quantum effects. To account for these effects in the simulation
E_{g} of the channel material is adapted according to the
calculations shown in Section 2.2.
Next: 4.3.2 Mobility Up: 4.3
Physical Parameters Previous: 4.3 Physical
Parameters
Helmut Brech 19980311