Compound semiconductors for low-noise microwave MESFET applications

In order to determine the low-noise potential of microwave MESFET's fabricated from materials other than GaAs, a one-dimensional FET model is employed. From material parameters and device geometry the model enables the calculation of a small-signal equivalent circuit from which performance information is acquired. Material parameters, as predicted from Monte Carlo calculations, are used to simulate 1-µm devices fabricated from GaAs as well as InP, Ga
0.47
In
0.53
As, InP
0.8
As
0.2
, Ga
0.27
In
0.73
P
0.4
As
0.6
, and Ga
0.5
In
0.5
As
0.96
Sb
0.04
. Results obtained from simulations comparing a Ga
0.5
In
0.5
As
0.96
- Sb
0.04
device to an equivalent GaAs device indicate that a decrease in minimum noise figure of almost a factor of two is possible. Considerable improvement in noise performance over a GaAs device is also predicted for devices fabricated from Ga
0.47
In
0.53
As and Ga
0.27
In
0.73
P
0.4
As
0.6
. In addition, the quaternary and ternary devices as well as the InP device should exhibit superior gain and high-frequency performance compared to GaAs devices.