The StaMPS export tool needs two layers: a layer with coregistred images+deburst (layer1) and another layer (layer2) with interferograms which topographic phase is removed.
Layer1 is obtained with backgeocoding+deburst of images.
As the results obtained with the topographic tool are wrong, I created interferograms for individual pairs and then created a stack (layer3).
For example, in case of 5 images, of which 1 master and 4 slaves, i created layer3 in this way:
1) I processed 4 single pairs (backgeocoding, deburst (and possibly subset), interferogram, topographic phase removal, export) and I obtained 4 different results.
2) I created a stack of these 4 results / pairs (with Create stack tool). In this stack, the images must be renamed with a name compatible with what appears in layer1 (for example, if the pair is 29Apr2015 and 22Jul2015, in layer1 you have i_IW1_VV_mst_29Apr2015, q_IW1_VV_mst_29Apr2015, i_IW1_VV_slv_22Jul2015, q_IW1_VV_slv_22Jul2015, in layer3 your renamed image must be i_ifg_VV_29Apr2015_22Jul2015 and q_ifg_VV_29Apr2015_22Jul2015).
After layer3 was created, I used layer1 and layer3 for export into stamps.