Metallization system of a semiconductor device comprising extra-tapered transition vias

摘要

In a metallization system of a semiconductor device, a transition via may be provided with an increased degree of tapering by modifying a corresponding etch sequence. For example, the resist mask for forming the via opening may be eroded once or several times in order to increase the lateral size of the corresponding mask opening. Due to the pronounced degree of tapering, enhanced deposition conditions may be accomplished during the subsequent electrochemical deposition process for commonly filling the via opening and a wide trench connected thereto.

主权项

1. A method, comprising:
forming an etch mask above a dielectric material of a first metallization layer of a semiconductor device, said etch mask comprising a mask opening having a first lateral size corresponding to a target lateral size at a bottom of a via to be formed in said dielectric material; forming a via opening on the basis of said mask opening having said first lateral size, said via opening extending to a first depth in said dielectric material; increasing a lateral size of said mask opening from said first lateral size to a second lateral size; increasing a depth of said via opening in said dielectric material from said first depth to a second depth on the basis of said mask opening having said second lateral size, wherein after increasing said depth, a lateral size of a top of said via opening is greater than a lateral size of a bottom of said via opening; after increasing said depth of said via opening, forming a trench above said via opening in said dielectric material so as to connect to said via opening; and commonly filling said via opening and said trench with a metal-containing material, said via opening extending to a metal region of a second metallization layer located below said first metallization layer.