Hh. Busta et al., COLLECTOR-ASSISTED OPERATION OF MICROMACHINED FIELD-EMITTER TRIODES, I.E.E.E. transactions on electron devices, 40(8), 1993, pp. 1537-1542
The field at the tip of a field emitter triode can be expressed by E =
betaV(g) + gammaV(c) with V(g) and V(c) the gate and collector voltag
es, respectively. For small gate diameters and tips below or in the pl
ane of the gate and/or large tip-to-collector distances, gammaV(c) <<
betaV(g). The device is operated in the gate-induced field emission mo
de and the corresponding I-V(c) curves are ''pentode''-like. By increa
sing the gate diameter and/or recessing the gates from the tips, colle
ctor-assisted operation can be achieved at reasonable collector voltag
es. Results will be presented for two devices with gate diameters of 3
.6 and 2.0 mum. By obtaining gamma at different emitter-to-collector d
istances, I-V(c) and transconductance g(m)-V(g) curves have been calcu
lated and compared with experimental results. It will be shown that as
a consequence of collector-assisted operation, the transconductance o
f a device can be increased significantly.