First PCB design, PWM Motor Controller feedback
What's the purpose of the capacitor on the output of gate driver IC, and where did you found that 100 ohm gate resistors are good choice.
Next, why the gate driver is so far away from MOSFETs? Also, gate traces may be too thick, the inductance is increased, however you didn't mention the PWM frequency, if enough low this won't be an issue.
I don't see that MOSFETs have both drain and source connected on PCB layout.
EDIT:
The absolute maimum rating for U3 is 20V, while datasheet says that the working voltage is 4.5 to 18V, therefore you can't use 20V as Vcc.
The cap on the U3 output mentioned on page 10 of its datasheet is used for a test, it simulates the gate capacatance of the MOSFEET, but it is not intended that you mount a capacitor on the output in real project.
The gate resistor is usually very low from 3 to 10 ohm, surely not 100.