See attachment at...
Newsgroups: alt.binaries.schematics.electronic Subject: Power MOS, Log(ID) versus Gate-Source Voltage - LogIDvsVGS.pdf Message-ID:
All the discussions here and in A.B.S.E about cobbling up a "patched" power MOS Spice model to cover low-voltage-low-current characteristics have always struck me as dangerous, fraught with possibility for error in other parameters.
The attachment shows how Level=7 seems to naturally cover the region.
So I think two things are in order...
(1) Harass Power MOS manufacturers to provide a correct Spice model
or
(2) Roll you own, but use Level=7 parameters rather than patching.
...Jim Thompson