What causes a mosfet to oscillate? I have a high power h-bridge,
the circuit was set up so that the turn-on turn-off of the fet’s was
fast. However, since I am switching into a reactive load, to limit the
inrush current, I was told to slow down the rise time of the lower half of
the h-bridge (in effect current limit the h-bridge on turn on).

Now that I have slowed down the rising edge, the fets oscillate during
the transition. I am not sure what to do about this, or even where to
begin. I did replace the reactive load with a resistive load, and the
slowed down h-bridge does not oscillate. One person recommended placing a
small capacitor from gate to source… does this make sense? Will this
extra capacitance just make the mosfet switch even slower?

My switching speed is under 1kHz, and the mosfets oscillate around 16MHZ.
I have a fet driver driving the mosfets, there is a gate resistor (with a
diode across it so that turn off time is faster then rise time).

To me, this is the start of where electronics becomes voodoo.