What is the Islamic position on the levirate marriage?

I saw a Jewish scholar (Jacob Emden ) claim that according to Islam, when a man dies without children then it is forbidden for his brother to marry the widow, but if he dies *with* children, then the living brother is *supposed* to marry his dead brother's widow. Is this true? (This is the exact opposite of the Jewish levirate marriage whereby if the deceased brother was childless, the living brother must marry the widow, and if the deceased brother was not childless, he is forbidden from marrying her.) I saw https://en.wikipedia.org/wiki/Levirate_marriage#Islam but this doesn't give me enough information.