No, the death benefit paid to you by your father's life insurance is not taxable income, unless you were also paid interest.
The following guidance is provided from IRS Pub. 525 Taxable and
Nontaxable Income:
"Life Insurance Proceeds
Life insurance proceeds paid to you because of
the death of the insured person aren't taxable
unless the policy was turned over to you for a
price. This is true even if the proceeds were
paid under an accident or health insurance policy or an endowment contract. However, interest income received as a result of life insurance
proceeds may be taxable.
Proceeds not received in installments. If
death benefits are paid to you in a lump sum or
other than at regular intervals, include in your
income only the benefits that are more than the
amount payable to you at the time of the insured person's death. If the benefit payable at
death isn't specified, you include in your income
the benefit payments that are more than the
present value of the payments at the time of
death.
Proceeds received in installments. If you receive life insurance proceeds in installments,
you can exclude part of each installment from
your income.
To determine the excluded part, divide the
amount held by the insurance company (generally the total lump sum payable at the death of
the insured person) by the number of installments to be paid. Include anything over this excluded part in your income as interest."
