Yes, if someone lived in 2018 and had more than $10,400 income as a single filer, you should file a final 1040 for him.
Follow these links for more information:
IRS on
Deceased Taxpayer
E-file
Deceased Tax Returns
https://turbotax.intuit.com/tax-tips/family/death-in-the-family/L5albFXM4
I am sorry for your loss.
