Do you have to pay tax on your deceased sons super and death policy?

Insurance benefits are considered part of the decedent's estate. There are (theoretically) estate taxes due on them, but unless your son had a lot of other assets or an unusually large policy it's unlikely that there will be any estate tax due; the first five million dollars of the estate's assets (roughly) are exempt from federal estate taxes (it may not be exempt from state taxes, though; check with a tax professional if you're not sure).

Benefits received from someone's estate are not subject to income tax.