According to the IRS FAQs:
If you can't cash or deposit the payment on behalf of any other individual who died in 2021:
The IRS says that a stimulus payment made to someone who died before receiving it should be returned to the government. The entire payment should be returned, unless it was made payable to joint filers and one spouse is still alive. In this case return only the portion for the deceased spouse.
It depends when your father passed away. According to the IRS, your father was not eligible for the second round of Economic Impact Payments if he passed away before 2020.
He would have been eligible if he was a U.S. citizen or U.S. resident alien, has a social security number (SSN) valid for employment (see exception when married filing joint) and your their adjusted gross income (AGI) does not exceed:
To read the IRS Questions and Answers about the Second Economic Impact Payment, click here and scroll down to Eligibility.
If you need to return the payment, scroll down to Returning the Second Economic Impact Payment.
According to the IRS FAQs:
If you can't cash or deposit the payment on behalf of any other individual who died in 2021:
The IRS says that a stimulus payment made to someone who died before receiving it should be returned to the government. The entire payment should be returned, unless it was made payable to joint filers and one spouse is still alive. In this case return only the portion for the deceased spouse.