Double heterostructure Ga0.47In0.53As MESFETs by MBE

Ga
0.47
In
0.53
As MESFETs have been fabricated on InP substrates. The low barrier height of Ga
0.47
In
0.53
As (0.20 eV) which makes simple GaInAs MESFETs at this composition impractical, has been overcome by using thin Al
0.48
In
0.52
As layers between gate metal and GaInAs active layers. Al
0.48
In
0.52
As has also been exploited in the form of buffer layers. The double heterostructure FET wafers with single crystal Al gate metal were grown by molecular beam epitaxy (MBE). The 2.75 µm gate length MESFETs showed d.c. transconductance g
m
= 57 mS mm
^-1
in spite of nonoptimized dimensions.