Patent attributes
The present invention provides a method for making a vertical interconnect through a substrate. The method makes use of a sacrificial buried layer 220 arranged in between the first side 202 and the second side 204 of a substrate 200. After having etched trenches 206 and 206′ from the first side, the sacrificial buried layer 220 functions as a stop layer during etching of holes 218 and 218′ from the second side, therewith protecting the trenches from damage during overetch of the holes. The etching of trenches is completely decoupled from etching of the holes providing several advantages for process choice and device manufacture. After removing part of the sacrificial buried layer to interconnect the trenches and the holes, the resulting vertical interconnect hole is filled to form a vertical interconnect.
