The effect of small transverse dimensions on the operation of Gunn devices

For the formation of dipole domains in specimens of GaAs, it is normally required that the product of donor density n and length be nL > 5 × 10
¹¹
cm
^-2
. For surface oriented Gunn diodes prepared on thin epitaxial GaAs layers, it is shown theoretically that under certain conditions the oscillation criterion is now nd ≥ 1.6 × 10
¹¹
cm
^-2
, where d is the film thickness.