We studied the exclusive reaction ep-->e'p'phi using the phi-->K+K- decay m
ode. The data were collected using a 4.2 GeV incident electron beam and the
CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson Nationa
l Accelerator Facility. Our experiment covers the range in Q(2) from 0.7 to
2.2 GeV2, and W from 2.0 to 2.6 GeV. Taken together with all previous data
, we find a consistent picture of phi production on the proton. Our measure
ment shows the expected decrease of the t slope with the vector-meson forma
tion time c Delta tau below 2 fm. At (c Delta tau) = 0.6 fm, we measure b p
hi = 2.27 +/- 0.42 GeV-2. The cross section dependence on W as W0.2+/-0.1 a
t Q(2) = 1.3 GeV2 was determined by comparison with phi production at HERA
after correcting for threshold effects. This is the same dependence as obse
rved in photoproduction.