NH3 and PH3 molecule shape



hello,
i have read that the difference in the shape of molecule of NH3 and
PH3 stems from different hybridization. can anybody explain me this?
electron configurations of N and P are rather similar (2s2 2p3 and 3s2
3p3). why they are different in shape? is VSEPRT helpful in this case?

thank you.
.