The IRS gives the following guidance about whether or not a deceased person can receive a stimulus check:

A10. No. A Payment made to someone who died before receipt of the Payment should be returned to the IRS by following the instructions in the Q&A about repayments. Return the entire Payment unless the Payment was made to joint filers and one spouse had not died before receipt of the Payment, in which case, you only need to return the portion of the Payment made on account of the decedent. This amount will be $1,200 unless adjusted gross income exceeded $150,000.

If your deceased loved one has received a stimulus check and you need guidance on repayment, go to the IRS website here. Go to Question 41 for details.