Is the وقف (pause/stop) on the word "فداء" in the noble verse "فإما منا بعد وإما فداءً" with an alif or with sukoon on the hamza?

If the reciter pauses at the word "fida'an" from the Almighty's saying: ﴿فَإِمَّا مَنًّا بَعْدُ وَإِمَّا فِدَاءً﴾ (…either a favor afterwards or a ransom), then he should pause on it with an alif, and not by silencing the hamza, because the alif is necessary for it when pausing, as a substitute for the tanween.