the material used in this invention is done either by using wet chemical techniques or by plasma for the materials of types 1 1a 1 1b or 1 1c typical wet chemical etching solutions use various proportions of hf hno 3 and h 2 o depending upon the etch rate desired typical gas mixtures used in plasma etching are cf 4 4 o 2 or other combinations with cf 4 if pt is used at step 1 1d sputter etching or lift off techniques need to be used if w is used at 1 1d either wet chemical h 2 o 2 etching or plasma etching with cf 4 4 o 2 is done steps 2 9 are the same in fig4 as in fig1 except that the first metal mask in step 7 does not have oversized regions around vias the next step of depositing interlayer dielectric can be done either in the conventional way as in step 10 of fig1 or one of the following 2 ways for improved etching of vias 10a deposit a doped and graded vapox such that the etch rate of the vapox in contact and near the first metal is lower than the upper part of the vapox in the etchant used for via etching a simple case will be to use an undoped vapox layer about 1 000 2 000 u00e5 thick to be deposited first and to deposit a doped vapox 5 8 by weight of phosphorus in sio 2 about 6 000 10 000 u00e5 thick the etch rate of the doped vapox is much higher than that of the undoped vapox in hf based etches thus undercutting during via etching to give a.